WO2009094367A1

WO2009094367A1 - Systems and methods to control electrical systems of vehicles

Info

Publication number: WO2009094367A1
Application number: PCT/US2009/031525
Authority: WO
Inventors: C. Richard Owens, Jr.; Nick Scheufler; John Sgueglia; Toshihiro Okama; Tadashi Fujiwara; Makoto Murata
Original assignee: Honda Motor Co., Ltd.
Priority date: 2008-01-22
Filing date: 2009-01-21
Publication date: 2009-07-30
Also published as: EP2238668A4; JP5351904B2; JP2011512784A; EP2238668A1

Abstract

As described herein, a generator control system is provided in a vehicle having an engine that drives an electric power generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle. The generator control system includes: a sensor that detects at least a state of charge (SOC) of the battery; and, a controller that controls at least a voltage output mode of the generator in response to the SOC detected by the sensor.

Description

SYSTEMS AND METHODS TO CONTROL ELECTRICAL SYSTEMS OF VEHICLES

BACKGROUND The present disclosure generally relates to battery control systems and methods for vehicles, and particularly relates to a battery control system and method for a vehicle having an engine (e.g., an internal combustion engine). Control systems for power delivery of specific related systems are also discussed herein. New vehicle models continue to be responsive to consumer demands for an ever increasing number of electrically powered features and devices. These features and devices add an additional burden to the vehicle's battery and thus more consideration is needed for maintaining the battery. Examples of such features and devices are memories for preferred positions of electrically adjustable devices, such as seats and mirrors, and memories for other electrically powered devices, such as radios having tuning presets. Still other examples include clocks, user specified navigational information, etc. The foregoing examples of features and devices that tax the vehicle's battery are normally of the type that cannot be manually isolated from the vehicle's battery by the driver. In addition to these, electrical components and devices of a vehicle can be inadvertently left on when their use is no longer desired and/or the vehicle is unattended. Obviously, this can further stress a vehicle's battery.

When a battery is overly discharged (such as by powering too many devices and features and/or inadvertently powering a device for an extended period without being recharged), the battery may no longer hold sufficient charge such as may be necessary, for example, for starting an internal combustion engine of a vehicle, if so equipped. Moreover, as the battery ages, it may become more susceptible to such over discharging, as vehicle batteries are known to degrade over time and with repeated cycles of charging and discharging. Accordingly, it is desirable to maintain a healthy battery condition by monitoring the loads on the battery and selectively electrically connecting and/or disconnecting such loads under certain operating conditions. To maintain the general health of a battery in good condition and/or to retain sufficient charge in the battery for starting the vehicle's engine, it is generally advantageous to protect a vehicle's battery from excessive discharge. As can be appreciated, however, some of the foregoing examples of electronic features and/or devices that tax the vehicle's battery are normally of the type that cannot be manually isolated from the vehicle's battery by the driver or other vehicle occupant. Additionally, electrical components and/or devices of a vehicle can be inadvertently left on when their use is no longer desired and/or the vehicle is unattended. Clearly, this can further stress a vehicle's battery unduly.

Accordingly, a new and improved system and/or method for protecting a vehicle battery from excessive discharge is disclosed that overcomes the above-referenced problems and others.

Generally, the trend is to provide more electronic features and/or devices in a vehicle, which typically results in additional burden on the vehicle's battery and/or electrical system. Moreover, automobiles and/or other motor vehicles have been or are now being developed which additionally make use of the battery and/or electrical system to control, power and/or assist in the operation of features and/or systems which are increasingly important to the safe overall operation, driving and/or other like use of the vehicle (e.g., including electric brakes, electric steering, etc.). Accordingly, it becomes even more prudent to pay meaningful consideration to monitoring the battery and/or electrical system to be sure they are functioning properly.

Accordingly, a new and improved system and/or method is disclosed for detecting an open circuit fault in the ground circuit of a vehicle's electrical system.

Typically, a vehicle's electrical system also includes an alternating current generator (ACG) or other like device that is driven by the engine to produce electric power when the engine is running. An ACG is also commonly known as an alternator and in a more general case the electric power producing device may simply be a generator. For the sake of convenience however, the term ACG has generally been used in the present specification. Nevertheless, as used herein, any of the terms and/or devices (i.e., ACG, alternator or generator) may suitably be substituted for any other term or device as deemed appropriate for particular applications.

Generally, the ACG is arranged to selectively provide electric power to the aforementioned loads and/or to charge the battery. The amount of electric power produced and/or output by the ACG is generally dependent upon the rotational speed at which the ACG is driven and accordingly upon the rotational speed of the engine which is driving the ACG. That is to say, when the engine is operating at a relatively lower rpm (revolutions per minute), then the output of the ACG is correspondingly lower and when the engine is operating at a relatively higher rpm, then the output of the ACG is correspondingly higher.

As can be appreciated, while the vehicle engine is idling, changes in the operation of various different electric loads may affect the SOC of the battery. For example, an increase in the use of electric power by the electric loads may tend to result in an undesirable reduction in the SOC of the battery. Accordingly, in such cases it is generally advantageous to increase the idle speed of the engine so as to produce more electric power output from the ACG to thereby compensate for the increased demand from the loads and/or suitably provide for charging of the battery to promote desired SOC recovery. Alternately, when the battery SOC is sufficiently high, it is generally desirable to maintain the idle speed of the engine relatively low insomuch as obtaining additional electrical power output from the ACG is not a concern and the lower engine idle speed tends to conserve fuel.

It is therefore generally advantageous, for at least the aforementioned reasons, to adjust engine idle speeds up or down and thereby regulate or otherwise control the ACG electric power output to compensate for changes in the operation of the various different electric loads and/or to maintain a desired battery SOC. However, at particular engine idle speeds, undesired noises or vibrations can be generated or otherwise experienced in the vehicle's engine, exhaust or at other locations, e.g., due to resonance or other causes. If significant enough, such noises or vibrations can cause a driver and/or passenger of the vehicle to be dissatisfied and/or uncomfortable with the driving experience. Additionally, at particular idle speeds, emissions control may be suboptimal and/or driveline (i.e., transmission) torque and/or losses may increase.

Accordingly, a new and improved system and/or method is disclosed that overcomes the above-referenced problems and others by controlling the engine idle speed in response to the detected SOC of the battery while avoiding selected engine idle speeds, e.g., identified as being associated with an undesirable generation of noise and/or vibrations; undesirable driveline and/or transmission torque and/or losses; and/or undesirable emissions control. As is known in the art, during the vehicle manufacturing process it is generally desirable to test various electrical components or systems of a vehicle. Accordingly, the vehicle battery is often operatively connected to selected circuits and/or electrical loads while such tests are conducted. However, to protect the battery from undesirable drainage or loss of charge after manufacture (e.g., during shipping and/or storage), it has commonly been the practice after completing the aforementioned testing to disconnect selected circuits or loads from the battery by manually removing or physically disconnecting a corresponding fuse typically arranged between the battery and the load or circuit that is to be isolated. While generally effective, this approach can be time consuming and labor intensive with respect to the manufacturing process. Furthermore, physically removing the fuse from its proper location generally increases the risk that the fuse may become lost or misplaced.

Additionally, the aforementioned approach generally requires replacement of the fuse before delivery of the vehicle to a customer. To maximize battery protection, it is typically preferred that the fuse be replaced just before the customer takes delivery of the vehicle. In this manner, the battery remains isolated from the otherwise current drawing load, e.g., while the vehicle sits in inventory on a dealer's lot. The dealer is therefore commonly responsible for replacing the fuse at the appropriate time. Nevertheless, dealer compliance can be difficult to ensure. For example, a dealer may replace the fuse at or near the time they receive the vehicle, thereby causing the battery charge to drain or diminish while the vehicle remains on their lot. Alternately, a dealer may forget to replace the fuse before the vehicle is delivered to a customer. In either case, customer dissatisfaction can result.

Accordingly, a new and improved method and/or system is disclosed that overcomes the above-referenced problems and others by automatically isolating one or more electrical current drawing loads from a vehicle battery after completing desired testing in connection with the manufacturing processes.

A conventional generator or ACG of the type typically employed in an automotive vehicle is usually free to selectively operate in and/or cycle between one of two voltage output modes, e.g., depending on the operative state of the loads and/or demand for electric power from the generator or ACG. For example, in a first or HI output voltage mode, the output voltage of the generator or ACG is typically about 14.5 volts (V), and in a second or LO output voltage mode, the output voltage of the generator or ACG is typically about 12.5 V. Accordingly, when the electric power demand is relatively high or heavy, the generator or ACG normally operates in the HI output voltage mode, and when the electric power demand is relatively low or light, the generator or ACG normally operates in the LO output voltage mode. In customary automotive applications, the generator or ACG is generally free to selectively cycle between the two modes as the electric power demanded from the generator or ACG varies, e.g., due to changes in the operative states of the various loads.

In any event, while generally acceptable, the foregoing conventional operation of the ACG or generator may still not provide for suitable maintenance of the battery at a desired SOC in all circumstances. For example, continual operation of the ACG or generator in the HI voltage output mode, can result in overcharging of the battery and/or inefficient use of the vehicle's fuel - i.e., wasted fuel. Conversely, continual operation of the ACG or generator in a LO voltage output mode, can result in insufficient electrical power generation to effectively maintain the battery's SOC at or above a desired level.

Accordingly, a new and improved system and/or method is disclosed that overcomes the above-referenced problems and others by suitably controlling the output voltage of the ACG or generator. BRIEF DESCRIPTION

According to one aspect, a battery control system for a vehicle is provided. More particularly, in accordance with this aspect, the battery control system includes a battery for supplying electrical power in the vehicle. A controller receives a battery signal representative of a condition of the battery, an ignition key signal representative of a state of an ignition key of the vehicle, and an engine signal representative of a state of an internal combustion engine in the vehicle. At least one load is selectively connected to the battery by the controller in response to at least one of the battery signal, the ignition key signal and the engine signal. An interface provides information on at least one of the battery and a connection state between the at least one load and the battery.

According to another aspect, a battery control method is provided for a battery of a vehicle that provides electrical power to a plurality of loads of the vehicle. More particularly, in accordance with this aspect, a battery signal representative of a condition of the battery is received. An ignition key signal representative of a state of an ignition key of the vehicle is also received, along with an engine signal representative of a state of an internal combustion engine of the vehicle. The plurality of loads of the vehicle are selectively electrically connected to the battery based on at least one of the battery signal, the ignition key signal and the engine signal. Information on at least one of the battery and a connection state between at least one of the plurality of loads and the battery is provided.

According to yet another aspect, a control system for a battery in a vehicle is provided. More particularly, in accordance with this aspect, the control system includes a battery for supplying electrical power in the vehicle. A controller receives a battery signal representative of a condition of the battery, an ignition key signal representative of a state of an ignition key of the vehicle, and an engine signal representative of a state of an engine in the vehicle. A plurality of loads is selectively electrically disconnected from the battery by the controller in response to the battery signal, the ignition key signal and the engine signal. The controller electrically disconnects a load A1 of the plurality of loads when the ignition key signal indicates that the ignition key is not in an ON position and the battery signal indicates the condition of the battery to be below a threshold A1. The controller electrically disconnects a load A1 +N of the plurality of loads from the battery when the ignition key signal indicates that the ignition key is not in the ON position and the battery signal indicates that the condition of the battery is below a threshold A1+N. The threshold A1+N is lower than the threshold Al An interface provides a message A1 when the load A1 is electrically disconnected from the battery and provides a message A1 +N when the load A1+N is electrically disconnected from the battery.

According to yet another aspect, a method of protecting a battery is provided in a vehicle having a battery that selectively supplies electric power for starting an engine of the vehicle and that selectively supplies electric power to a plurality of electric loads of the vehicle. The method includes: obtaining a temperature; determining a state of charge (SOC) of the battery; determining a first threshold based on the obtained temperature; determining a second threshold based on the obtained temperature, the second threshold being different than the first threshold; taking a first remedial action if the SOC is below the first determined threshold; and taking a second remedial action if the SOC is below the second determined threshold, the second remedial action being different from the first remedial action. According to yet another aspect, a system for protecting a battery is provided in a vehicle having a battery that selectively supplies electric power for starting an engine of the vehicle and that selectively supplies electric power to a plurality of electric loads of the vehicle. The battery protection system includes: temperature sensing means for obtaining a temperature; battery sensing means for determining a state of charge (SOC) of the battery; threshold determining means for determining a first threshold based on the temperature obtained by the temperature sensing means and a second threshold based on the temperature obtained by the temperature sensing means, the second threshold being different than the first threshold; and remedial action means for taking a first remedial action if the SOC is below the first determined threshold and a second remedial action if the SOC is below the second determined threshold, the second remedial action being different from the first remedial action. According to still another aspect, a battery protection system is provided in a vehicle having a battery that selectively supplies electric power for starting an engine of the vehicle and that selectively supplies electric power to a plurality of electric loads of the vehicle. The battery protection system includes: a first sensor that measures at least one of a temperature of the battery, a temperature of the vehicle's engine and an ambient temperature; a second sensor that detects a state of charge (SOC) of the battery; and a controller that: (i) determines a plurality of different thresholds based upon the measurement from the first sensor; (ii) compares the SOC detected by the second sensor to the plurality of thresholds; and (iii) selectively triggers a plurality or different remedial actions in response to comparing the detected SOC to the plurality of different thresholds.

According to yet another aspect, in a vehicle having an electrical system including a ground circuit that provides an operative connection from the electrical system to an electrical ground and an electric power generator driven by an engine of the vehicle, the generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle, a fault detection system is provided for detecting an open circuit or high resistance fault in the ground circuit. The fault detection system includes: a controller that controls a voltage output of the generator so as to at least one of restrict or suspend charging or increase or start charging of the battery by the generator for a designated test period; and, determining means for determining a current discharge from the battery or a charging current into the battery during the test period, wherein if the determined current discharge or charging current is less than a given threshold, then an open circuit or high resistance fault is deemed to be detected in the ground circuit.

According to another aspect, in a vehicle having an electrical system including a ground circuit that provides an operative connection from the electrical system to an electrical ground and an electric power generator driven by an engine of the vehicle, the generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle, a method is provided for detecting an open circuit or high resistance fault in the ground circuit. The method includes: controlling a voltage output of the generator so as to at least one of restrict or suspend charging or increase or start charging of the battery by the generator for a designated test period; and, determining a current discharge from or charging current into the battery during the test period, wherein if the determined current discharge or charging current is less than a given threshold, then an open circuit fault is deemed to be detected in the ground circuit.

According to yet another aspect, an engine idle control system is provided in a vehicle having an engine that drives an electric power generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle. The engine idle control system includes: a sensor that detects a state of charge (SOC) of the battery; and a controller that controls an idle speed of the engine in response to the SOC detected by the sensor, wherein the controller is provisioned to skip at least one specific engine idle speed that has been identified as a cause of at least one of: unwanted noise in the vehicle; unwanted vibrations in the vehicle; undesirable emissions control; or undesirable driveline torque.

According to yet another aspect, an engine idle control system is provided in a vehicle having an engine that drives an electric power generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle. The engine idle control system includes: sensing means for detecting a state of charge (SOC) of the battery; and control means for controlling an idle speed of the engine in response to the SOC detected by the sensing means, wherein the control means is provisioned to skip at least one specific engine idle speed that has been identified as a cause of at least one of: unwanted noise in the vehicle; unwanted vibrations in the vehicle; undesirable emissions control; or undesirable driveline torque.

According to still another aspect, a method for controlling a idle speed of the engine is provided in a vehicle having an engine that drives an electric power generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle. The method includes: identifying an engine idle speed that is a cause of at least one of: unwanted noise in the vehicle; unwanted vibrations in the vehicle; undesirable emissions control; or undesirable driveline torque; determining a state of charge (SOC) of the battery; and adjusting the idle speed of the engine in response to the determined SOC of the battery, wherein said adjustment of the idle speed of the engine is executed such that the identified engine idle speed is avoided.

According to still another aspect, a battery protection system is provided in a vehicle having an ignition system for selectively starting and stopping an engine of the vehicle and an electrical system including an electrical load and a battery that selectively delivers electric current to said load via a first device that protects said load from receiving excessive current. The battery protection system includes: a second device that selectively connects and disconnects the load from the battery; and a controller that controls said second device in response to a detected number of ignition cycles. According to yet another aspect, a method of protecting a battery is provided in a vehicle having an ignition system for selectively starting and stopping an engine of the vehicle and an electrical system including an electrical load and a battery that selectively delivers electric current to said load via a first device that protects said load from receiving excessive current. The method includes: detecting ignition cycles of the engine; counting the number of detected ignition cycles; and selectively disconnecting the load from the battery in response to the counted number of ignition cycles.

According to still another aspect, a battery protection system is provided in a vehicle having an ignition system for selectively starting and stopping an engine of the vehicle and an electrical system including an electrical load and a battery that selectively delivers electric current to said load. The battery protection system includes: means for detecting ignition cycles of the engine; means for counting the number of detected ignition cycles; and means for selectively disconnecting the load from the battery in response to the counted number of ignition cycles.

According to still another aspect, a generator control system is provided in a vehicle having an engine that drives an electric power generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle. The generator control system includes: a sensor that detects a state of charge (SOC) of the battery; and, a controller that controls a voltage output mode of the generator in response to the SOC detected by the sensor.

According to yet another aspect, a method for controlling a voltage output mode of a generator is provided in a vehicle having an engine that drives an electric power generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle. The method includes: determining a state of charge (SOC) of the battery; and, controlling a voltage output mode of the generator in response to the SOC.

According to still another aspect, a system for controlling a voltage output mode of a generator is provided in a vehicle having an engine that drives an electric power generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle. The system includes: means for determining a state of charge (SOC) of the battery; and, means for controlling a voltage output mode of the generator in response to the SOC.

According to another aspect, a system provides generator control for a power system within a vehicle. The system includes a battery, a generator that outputs power to charge the battery. A sensor detects a state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery. A controller controls a voltage output mode of the generator in response to at least one of a state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery detected by the sensor, the voltage output mode is in response to the SOC and the temperature of the battery.

According to yet another aspect, a method controls a voltage output mode of the generator in a vehicle having an engine that drives an electric power generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle. A state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery are determined. A voltage output mode of the generator is controlled in response to at least one of a state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery detected by the sensor, the voltage output mode is in response to the SOC and the temperature of the battery.

According to still another aspect, a system for controlling a voltage output mode of the generator is used in a vehicle having an engine that drives an electric power generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle. Means are employed to detect a state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery. Means are used to control a voltage output mode of the generator in response to at least one of a state of charge (SOC) value, a health value, a voltage, a current, a temperature, and a charging voltage of the battery detected by the sensor, the voltage output mode is in a linear response to SOC of the battery.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE 1 is schematic view of a battery control system for a vehicle. FIGURE 2 is a block diagram illustrating a battery control method for a battery of a vehicle that provides electrical power to a plurality of loads of the vehicle. FIGURE 3 is another block diagram illustrating a battery control method for the battery of a vehicle.

FIGURE 4 is still another block diagram illustrating a battery control method for the battery of a vehicle.

FIGURES 5a-5c illustrate various notifications or messages that can be provided to a vehicle operator to indicate a condition of the vehicle's battery and/or a connection state between one or more loads on the battery and the battery itself.

FIGURE 6 is an exemplary diagram showing the prioritization of various loads on a vehicle's battery. FIGURE 7 is a schematic diagram showing an exemplary battery protection system of a vehicle suitable for practicing aspects of the present disclosed subject matter. FIGURE 8 is a flow chart showing an exemplary process for protecting a battery from excessive discharge in accordance with aspects of the present disclosed subject matter.

FIGURE 9 is a schematic diagram showing an exemplary electrical system of a vehicle suitable for practicing aspects of the present disclosed subject matter.

FIGURE 10 is a flow chart showing an exemplary process for detecting an open circuit and/or high resistance fault in a vehicle's electrical system in accordance with aspects of the present disclosed subject matter. FIGURE 11 is a flow chart showing another exemplary process for detecting an open circuit and/or high resistance fault in a vehicle's electrical system in accordance with aspects of the present disclosed subject matter.

FIGURE 12 is a schematic diagram showing an exemplary engine idle speed control system of a vehicle suitable for practicing aspects of the present disclosed subject matter.

FIGURE 13 is a graph showing an exemplary plot of engine idle speed as a function of battery SOC in accordance with aspects of the present disclosed subject matter.

FIGURE 14 is a schematic diagram showing an exemplary electrical system of a vehicle suitable for practicing aspects of the present disclosed subject matter.

FIGURE 15 is a flow chart showing an exemplary process for automatically isolating an electrical load from a vehicle battery in accordance with aspects of the present disclosed subject matter. FIGURE 16 is a flow chart showing an exemplary process for selectively reconnecting an electrical load to a vehicle battery and/or disabling the automatic load isolating function.

FIGURE 17 is a schematic diagram showing an exemplary electric generator output voltage control system of a vehicle suitable for practicing aspects of the present disclosed subject matter.

FIGURE 18 is a flow chart showing an exemplary process for controlling an electric generator's output voltage in accordance with aspects of the present disclosed subject matter. FIGURE 19 is a chart that illustrates an electric generator's output voltage in accordance with aspects of the present disclosed subject matter.

DETAILED DESCRIPTION Referring now to the drawings, wherein the showings are for purposes of illustrating one or more exemplary embodiments, FIGURE 1 shows a battery control system 10 for a vehicle. In the illustrated embodiment, the battery control system 10 includes a battery 12 for supplying electrical power in the vehicle. Battery 12 can be a conventional battery, such as a 12 V battery, used to power a vehicle having an engine 14 (e.g., an internal combustion engine). The control system 10 can further include a controller 16 powered and/or linked to the battery 12. As used herein, a link or being linked is used broadly to cover any operative connection between components of the system 10 whether wired or wireless that enables the linked components to communicate (e.g., transmit a signal from one component to another). Though the controller 16 of FIGURE 1 is schematically shown as a central controller, it is to be appreciated by those skilled in the art that the controller 16 could be distributed throughout the system 10 or vehicle in which the system 10 is disposed. As is known and understood by those skilled in the art, the controller 16 can be implemented by a microcomputer comprised of a CPU, a ROM for storing various operating programs or modules to be executed by the CPU, a RAM for storing the results of computations or the like by the CPU and any number of input/output interfaces, none of which is shown in FIGURE 1. In addition to coordinating operation of the system 10, the controller 16, whether centralized or distributed, can store data obtained about the condition of the battery 12 for future diagnostic review (e.g., battery data stored by the controller 16 can be reviewed when the battery loses all of its charge and/or its ability to hold a sufficient charge). The control system 10 can further include a sensor unit 18 and an interface 20, both of which can be linked to the controller 16. The system 10 can also include an ignition switch or device 22 linked to the controller 16 for use in association with a key 24, which can be a conventional cut key, an electronic key or the like. As will be described in more detail below, the battery control system 10 includes at least one load, a plurality of loads 26, 28, 30, 32, 34 in the illustrated embodiment, that is selectively electrically connected/disconnected to the battery 12 by the controller 16. As will also be described in more detail below, the interface 20 provides information (e.g., audio and/or video information) on at least one of the battery 12 and a connection state between at least one of the loads 26-34 and the battery 12.

The controller 16 receives a battery signal 36 representative of a condition of the battery 12 from the sensor unit 18. The controller 16 also receives an ignition key signal 38 from the ignition switch or device 22 that is representative of a state of the ignition key 24 of the vehicle (e.g., the ignition key 24 is either in an ON position or in a key OFF or key REMOVED position). The controller 16 can further receive an engine signal 40 from the engine 14 representative of a state of the engine 14 (i.e., indicating that the engine is running or is off). Using at least one of these signals 36, 38, 40, the controller 16 can selectively electrically connect or disconnect one or more of the loads 26-34 from the battery 12. In one embodiment that will be described in more detail below, one or more of the loads 26-34 is electrically disconnected from the battery 12 in response to the battery signal 36, the ignition key signal 38, and the engine signal 40. In the illustrated embodiment, the sensor or sensor unit 18 is electrically connected to the battery 12 for determining the condition of the battery 12 and generating the battery signal representative thereof to send to the controller 16. The battery signal 36 can be one or more signals that indicate the condition of the battery 12. The condition can be a state of charge (SOC), such as a value indicating the charge remaining in the battery 12 relative to a scale ranging between a low end where no charge remains in the battery 12 and a high end where the battery 12 is fully charged (or overcharged). In addition, or in the alternative, the condition of the battery 12 can be a state of function (SOF) of the battery, such as an indication or value indicative of the cranking ability of the battery, the battery's cranking voltage, the battery's health or state or the like. For example, the sensor unit 18 could determine that the battery 12 lacks sufficient energy capacity or output capability to start the engine 14 and the signal 36 sent to the controller 16 could be representative of this indication. In one embodiment, the signal 36 indicates the condition of the battery as relates to its overall state of charge (i.e., a value or percentage of a maximum state of charge of the battery 12) and an indication of the cranking ability of the battery 12. In one exemplary embodiment, the state of charge is the percentage of maximum electrical energy output of the battery 12 and the cranking ability is the percent state of charge required to start the engine, which can vary by temperature and other external factors.

The loads 26-34 can be various electrical consuming devices or groups of devices within the vehicle. For example, first load 26 can be interior lighting within the vehicle and second load 28 can be backup functions (+B functions) of the vehicle. The remaining loads 30, 32, 34 can be, for example, headlights, windshield wipers, the entertainment or sound system, rear defogger, various customer accessories, trunk lights, navigational systems and displays or other displays (e.g., a rear entertainment screen), heated seats, ventilation blower, etc. Though the illustrated battery control system 10 is shown with loads 26-34, it is to be appreciated and understood by those skilled in the art that any number of loads could be selectively electrically connected by the controller 16 to the battery 12.

With additional reference to FIGURE 2, an exemplary battery protection or control method will now be described in association with the illustrated system 10 of FIGURE 1. In the method, the controller 16 receives the battery signal 36 that is representative of the condition of the battery 12 (step S50). The controller 16 also receives the ignition key signal 38 (step S52) that is representative of the state of the ignition key 24 (i.e., in the ON position or in the OFF or REMOVED position) and receives the engine signal 40 (step S54) representative of the state of the engine 14 (e.g., the state can either be on and running or off). Using at least one of the signals 36, 38, 40, (and using all of the signals 36-40 in one exemplary embodiment), the controller 16 selectively electrically connects/disconnects the loads 26-34 of the vehicle relative to the battery 12 (step S56). The controller 16 can also provide information on the interface 20 on at least one of the battery 12 (e.g., the condition of the battery) and/or a connection state between one or more of the loads 26-34 and the battery 12 (step S58). For example, the interface 20 can include a display or display portion for displaying said information. Alternatively, or in addition, the interface can include an audio or alarm producing device for providing audio or an alarm.

Turning to FIGURE 3, the battery protection or control method is shown in further detail according to one exemplary embodiment. More particularly, the illustrated method of FIGURE 3 includes receiving the battery signal 36, the ignition key signal 38, and the engine signal 40 (steps S60, S62, S64) but illustrates the steps S56 and S58 of FIGURE 2 in further detail. More particularly, for selectively electrically connecting/disconnecting the loads 26- 34 and the battery 12, the controller determines if the ignition key 24 is in the key ON position (step S66). If the ignition key 24 is not in the key ON position, the controller 16 electrically disconnects the first load 26, which can be interior lighting within the vehicle for example, from the battery when the battery signal 36 indicates the condition of the battery 12 is below a first predetermined threshold (e.g., such as below 80% of a full charge) (step S68). The controller 16 then commands the interface 20 to provide a first message when the first load 26 is electrically disconnected from the battery 12 (step S70). The first message can be an indication (e.g., a visual and/or an audio indication) that the first load 26 has been disconnected from the battery 12. For example, with reference to FIGURE 5A, an example first message is shown wherein the load 26 is interior lighting of the vehicle that has been disconnected from the battery 12. The example first message could be provided alone or with audio (e.g., an alarm).

Next, the controller 16 can electrically disconnect the second load 28, which can be backup functions of the vehicle (i.e., +B functions), when the ignition key signal 38 indicates that the ignition key 24 is in the key OFF position in step S66 and the battery signal 36 indicates that the condition of the battery 12 is below a second predetermined threshold (e.g., below 60% of full charge), wherein the second predetermined threshold is lower than the first predetermined threshold (step S72). Thus, the first predetermined threshold used in step S68 is associated or corresponds with the first load 26 and the second predetermined threshold used in step S72 is associated or corresponds with the second load 28. The controller 16 then commands the interface 20 to provide a second message when the second load 28 is electrically disconnected from the battery 12 (step S74). The second message can indicate (e.g., a visual and/or an audio notification) that the second load 28 has been disconnected from the battery 12. With reference to FIGURE 5b, an example second message is shown wherein the second load 28 is the backup function or +B power supply of the vehicle that has been disconnected from the battery 12. Like the example first message, the second message could be provided alone or with audio (e.g., another alarm).

Should a determination be made in step S66 that the ignition key 24 is in the key ON position, a second determination is made to determine whether the engine 14 is on or running (step S76). Using the method illustrated in FIGURE 3, the controller 16 commands the interface 20 to provide a message (step S78) when the ignition key signal 38 indicates that the ignition key 24 is in the ON position (in step S66), the engine signal 40 indicates that the engine 14 is off, and the battery signal 36 indicates that the condition of the battery 12 is below a predetermined threshold (e.g., 75% of a fully charged battery). Again, the message can be a visual and/or an audio message (e.g., a visual display accompanied by an alarm). This predetermined threshold, which is associated with the ignition key 24 being in the ON position and the engine being OFF, can be the same or different than the predetermined thresholds of steps S68 and S72. The message provided in step S78 can indicate that the condition of the battery 12 is below the predetermined threshold associated or corresponding with step S78. With reference to FIGURE 5c, in one exemplary embodiment, the message in step S78 can be a visual message as illustrated. This example message could be provided alone or with audio (e.g., an alarm). When the ignition key 24 is in the key ON position, as determined in step S66, and the engine 14 is on, as determined in step S76, the controller 16 can progressively disconnect each of the loads 26-34 (or a subset thereof) when the battery signal 36 indicates that the condition of the battery 12 is below a predetermined threshold that corresponds specifically to each of the loads 26-34 (step S80). As the loads are progressively disconnected in step S80, corresponding messages can be provided when the loads are disconnected (step S82), though this is not required. Like the other messages, these messages can be visual and/or audio messages. The predetermined threshold or thresholds corresponding to each of the loads 26- 34 (and thus the messages) can be set or prioritized based on one or more predetermined factors. For example, the prioritization of the loads 26-34 can be based on regulations, importance to the customer, and/or energy or power usage, etc. In the system 10, these and other factors can be used to determine an importance consideration for a load or a group of loads. The importance consideration can be, for example, a valve or position assigned to a load or group of loads that prioritizes or ranks the load or group of loads relative to other loads or groups of loads.

More particularly, and with additional reference to FIGURE 6, the loads or groups of loads of the vehicle can be prioritized due to an assigned importance consideration versus energy consumption (i.e., power consumption x energized time). Thus, for example, a comfort accessory load which may have a relatively lower assigned importance consideration could have its threshold set so as to be electrically disconnected prior to a visual lighting system load, which may use approximately the same amount of energy but have a higher assigned importance consideration. As a further example, a convenience load could have a threshold set so as to be disabled sooner than a telematics load because, while being shown as having similar importance considerations, the convenience load may require more energy. Alternatively, some loads (e.g., vision/lighting systems and drive-by-wire devices) which may have a relatively higher importance consideration, could be removed from the system 10 so as to prevent being electrically disconnected from the battery 12 by the controller 16 or could have a threshold that is very low and is only met when the condition of the battery 12 is critical (e.g., just above a point where the engine can still be started).

With reference back to FIGURE 1 , the progressive electrical disconnection of the loads 26-34 from the battery 12 (i.e., step S80) will be described in a particular example. In this example, each of the loads 26-34 is associated or corresponds to a particular threshold (at least for step S80). Accordingly, the threshold for each load 26-34 is set so as to determine when the load 26-34 is electrically disconnected from the battery 12 based on the condition of the battery 12. In this example, the controller 16 could electrically disconnect the first load 26 from the battery 12 when the battery signal 36 indicates that the condition of the battery 12 is below a first predetermined threshold corresponding to the load 26 (e.g., 85% of full charge) and a corresponding message could be provided on the interface 20. Similarly, the second load 28 can be electrically disconnected from the battery 12 by the controller 16 when the battery signal 36 indicates that the condition of the battery 12 is below a second predetermined threshold that corresponds to the second load 28 (e.g., 75% of full charge) and another corresponding message could be provided on the interface 20. The additional loads 30-34 can then each, in turn, have an associated or corresponding predetermined threshold (e.g., 60% of full charge for load 30, 50% of full charge for load 32, and 20% of full charge for load 34).

In this manner, the controller 16 can progressively electrically disconnect the loads 26-34 from the battery 12 as the battery signal 36 indicates the condition of the battery 12 to be below each of the thresholds associated with the loads 26-34. Again, it is to be appreciated that the progressive electrical disconnection of loads 26-34 in step S80 occurs when the battery signal 36 indicates that the condition of the battery 12 is below each threshold associated with each load 26-34 and the ignition key signal 38 indicates that the ignition key 24 is in the key ON position (step S66) and the engine signal 40 indicates that the engine 14 is on (step S76). Through the progressive electrical disconnection of the loads 26-34 from the battery 12 by the controller 16, the condition of the battery 12 can be preserved or at least extended. Moreover, the decreasing condition of a battery 12 can be used to continue to electrically power only the loads of the vehicle having more important considerations. Optionally, the controller can progressively reconnect any of the loads

26-34 (or a subset thereof) after disconnection in step S80 when the battery signal 36 indicates that the condition of the battery is above a predetermined threshold that corresponds specifically to each of the disconnected loads 26- 34 (step S83). If desirable, the progressive reconnection of step S83 can use the same thresholds as used in step S80, though this is not required. For example, if load 26 is disconnected from the battery 12 when the battery signal 36 indicates that the condition of the battery is below a first predetermined threshold (e.g., 85% of full charge), the load 26 can be reconnected to the battery 12 when the battery signal 36 indicates that the condition of the battery returns above the first predetermined threshold. Of course, however, the reconnection of loads in step S83 could alternately use different thresholds than used in step S80 and such different thresholds can be established independently of those used in step S80 from the same factors and/or some other factors relating to prioritization of the loads. In addition, all loads, such as loads 26-34 can be reconnected to the battery 12 when a particular condition is met. For example, the condition could be cycling of the ignition key from its ON position to its OFF position and back to its ON position, or the condition could be some other resetting means (e.g., a reset button).

With reference now to FIGURE 4, a battery protection or control method is shown according to an alternate embodiment. More particularly, the battery protection method of FIGURE 4 is similar to that depicted in FIGURE 3, but allows for any number of loads to be progressively disconnected when the ignition key is not in the ON position, allows any number of messages to be displayed as the battery condition deteriorates when the ignition key is in the ON position and the engine is not running, and continues to allow progressive electrical disconnection and reconnection of the loads from the battery when the ignition key is in the ON position and the engine is on.

More specifically, the battery protection method depicted in FIGURE 4 can be used in association with the control system of FIGURE 1. Thus, in steps S84, S86, and S88, the controller 16 receives the battery signal 36, the ignition key signal 38, and the engine signal 40. Like steps S66 and S76 in FIGURE3, the method of FIGURE 4 includes steps S90 and S92 for, respectively, determining if the ignition key 24 is in the key ON position and if the engine 14 is ON. When the ignition key 24 is not in the key ON position, as determined in step S90, selected loads can be progressively disconnected electrically from the battery 12. More particularly, a load A1 can be electrically disconnected from the battery 12 when the battery condition is below a corresponding threshold A1 (step S94). The load A1 can be any one of the loads selectively electrically connected to the battery 12 by the controller 16. The threshold A1 can be a threshold that particularly corresponds to the selected load A1 and can be set for electrically disconnecting load A1 under the condition that the ignition key 24 is not in the key ON position. Next, in step S96, a message A1 can be provided when the load A1 is electrically disconnected. The message A1 , which can be a visual and/or audio message, can be specific to the condition of load A1 being disconnected due to the battery condition being below threshold A1 when the ignition key 24 is not in the key ON position.

This sequence can be repeated for any number of loads, as desired. Thus, in step S98 a load A1 +N can be electrically disconnected from the battery 12 when the battery condition is below a threshold A1 +N that corresponds to the load A1+N. The load A1 +N can be any load selectively electrically connected to the battery 12 by the controller 16, other than load A1. A message A1 +N can be provided when the load A1 +N is disconnected due to the battery condition falling below the corresponding threshold A1+N (step S100). This sequence of disconnecting a load when the battery condition is below a corresponding threshold and providing a corresponding message can be repeated for any number of additional loads as desired (i.e., N can be indexed upward as desired and steps S98 and S100 repeated as necessary).

When determined that the ignition key 24 is in the key ON position in step S90 and determined that the engine 14 is off in step S92, messages (e.g., visual and/or audio messages) can be progressively provided as the battery condition falls below a series of thresholds (step S102). For example, a message B1 can be provided when a battery condition falls below threshold B1. The threshold B1 can be the same as any of the thresholds A1 or A1+N, or can be some other threshold. This sequence can then be repeated for any number of additional messages corresponding to additional thresholds. For example, in step S104, a message B1+N can be displayed when the condition of battery 12 is below a corresponding threshold B1 +N. Then, N can be indexed upward as desired and step S104 repeated. When the ignition key 24 is in the key ON position as determined in step S90 and the engine 14 is on as determined in step S92, loads selectively electrically connected to the battery 12 by the controller 16 can be progressively disconnected as the battery condition falls below thresholds associated with each of the loads (step S106). For example, in step S106, load C1 can be electrically disconnected from the battery 12 when the battery condition falls below corresponding threshold C1. When load C1 is disconnected, a message C1 can be provided (step S108) to indicate that load C1 has been disconnected. Like the other messages, the message C1 can be a visual and/or an audio message (e.g., a text display and/or an audio alarm). Then, should the battery condition further deteriorate, a load C1 +N can be electrically disconnected from the battery 12 when the battery condition falls below a corresponding threshold C1+N (step S110). When load C1 +N is disconnected, a message C1+N can be provided (step S112) to indicate that load C1+N has been disconnected. This sequence can be repeated for any number of loads having corresponding thresholds (i.e., N can be indexed upward for however many loads and corresponding thresholds are desired). Though not shown, the loads C1 and C1+N can be reconnected to the battery as its condition improves in some manner as described in reference to step S83 of FIGURE 3, though this is not required.

Also, the loads C1 and C1 +N and corresponding thresholds C1 and C1+N can be the same or different than the loads A1 and A1 +N and corresponding thresholds A1 and A1+N. That is, the loads and thresholds of steps S106 and S108 need not be the same or ordered the same as the loads in corresponding thresholds in the steps S94-S100. For example, load A1 can correspond to load 26 in FIGURE 1 and have a threshold A1 set at 80% of full charge. Load A1 +N could then correspond to load 28 and have a corresponding threshold A1 +N that is 60% of full charge of the battery 12. Load C1 , however, could correspond to load 30 and threshold C1 could be set at 85% of full charge of the battery 12 and load C1+N could be set as load 26 and threshold C1+N could be set as 60% of full charge of the battery 12. In this manner, the selective electric disconnection of the loads 26-34, or any other loads, from the battery 12 can be optimized differently for the condition where the ignition key 24 is not in the key ON position than for the conditions where the ignition key is in the key ON position and the engine is on.

While one or more of the various embodiments have been described herein with reference to the battery's SOC, it is to be appreciated that SOC is merely an exemplary parameter that is sensed, measured and/or otherwise determined and accordingly used in one or more suitable manners as explained above. More generally and/or in alternate embodiments, other parameters indicative of and/or related to the battery's state of function (SOF) may similarly be obtained (i.e., sensed, measured and/or otherwise determined) and suitably used in place of the SOC. In this regard, examples of the battery's SOF include not only the battery's SOC but also the battery's cranking voltage, the internal resistance of the battery, the battery's reserve capacity, the cold cranking amperes (CCA) of the battery, the battery's health and the like. Accordingly, it is intended that the terms and/or parameters SOC and SOF when used herein may optionally be interchanged where appropriate to achieve various alternate embodiments suitable for particular desired applications.

It is to be appreciated that in connection with the particular exemplary embodiments presented herein certain structural and/or function features are described as being incorporated in defined elements and/or components. However, it is contemplated that these features may, to the same or similar benefit, also likewise be incorporated in common elements and/or components where appropriate. For example, the sensor 18 and controller 16 may suitably be integrated together. It is also to be appreciated that different aspects of the exemplary embodiments may be selectively employed as appropriate to achieve other alternate embodiments suited for desired applications, the other alternate embodiments thereby realizing the respective advantages of the aspects incorporated therein.

It is also to be appreciated that particular elements or components described herein may have their functionality suitably implemented via hardware, software, firmware or a combination thereof. For example, the controller 16 and/or sensor 18 may be implemented as appropriate hardware circuits or alternately as microprocessors programmed to implement their respective functions. Additionally, it is to be appreciated that certain elements described herein as incorporated together may under suitable circumstances be stand-alone elements or otherwise divided. Similarly, a plurality of particular functions described as being carried out by one particular element may be carried out by a plurality of distinct elements acting independently to carry out individual functions, or certain individual functions may be split-up and carried out by a plurality of distinct elements acting in concert. Alternately, some elements or components otherwise described and/or shown herein as distinct from one another may be physically or functionally combined where appropriate.

Referring now to FIGURE 7, which shows a schematic diagram of a battery protection system for a vehicle 710, e.g., such an automobile or other similar automotive vehicle. Suitably, the vehicle 10 includes an engine 712 (e.g., an internal combustion engine or the like) that drives the vehicle 710. The vehicle 710 is also provisioned with an electrical system including: a battery 714 which suitably provides a source of electric power for starting the engine 712 of the vehicle 710; and, one or more electric circuits or loads that may also be selectively powered by the vehicle's battery 714. For example, the loads may include: headlights, clocks, electrically powered adjustable components such as seats, mirrors or steering columns, interior cabin lights, electric heaters for seats, mirrors, windows or the like, radios and/or other entertainment systems, electronic memories for recording radio station presets and/or user preferred seat and/or mirror positions, electronic navigation systems, etc. In particular, there are two loads illustrated in FIGURE 7, namely, a first load 716 and a second load 718. Optionally, the first load 716 represents, e.g., interior cabin lights for the vehicle 710, while the second load 718 represents, e.g., backup electronic functions - also commonly referred to as "+B" functions. Suitably, the battery is a nominal 712 volt (v) battery of the type commonly employed in automobiles or may be any other type of battery, e.g., typically used in automotive applications.

According to one exemplary embodiment, the vehicle 710 is further equipped or otherwise provisioned with an ignition system for selectively starting and stopping the engine 712 of the vehicle 710. As illustrated in FIGURE 7, the ignition system suitably includes an ignition switch 20 or other like device use in conjunction with a key 722, e.g., which can be a conventional cut key, an electronic key or the like. In the usual fashion, the key 722 is optionally manipulated to selectively place the ignition switch 720 in either of two or more positions or states, namely, (i) a key ON position or state, or (ii) a key OFF position or state.

As shown in FIGURE 7, the battery protection system includes one or more devices such as relays 736 and 738 or other suitable switches or the like that are arranged between the battery 714 and the loads 716 and 718. Under the control of a controller 730 which is also part of the battery protection system, the relays 736 and 738 are selectively opened and closed. In their open states, each relay disconnects or otherwise isolates its respective the load from the battery 714 so that current or electric power from the battery 714 is cut-off to the corresponding load. That is to say, in practice, when the controller 730 detects one or more selected conditions or otherwise determines that certain criteria are met, the controller 730 sends a suitable control signal to the appropriate relay 736 and/or 738. In response to the control signal, the respective relay 736 and/or 738 is tripped or otherwise set to its open state thereby cutting-off the delivery of electric power or current from the battery 714 to the corresponding load 716 and/or 718. Alternately, in their normally closed states, the respective relays 736 and 738 operatively connect their corresponding loads 716 and/or 718 to the battery 714 so that electric power and/or current can be delivered from the battery 714 to the respective loads 716 and/or 718.

In the illustrated embodiment, the battery protection system also suitably includes: a state of charge (SOC) sensor 732 that senses, detects and/or otherwise determines a SOC or condition of the battery 714; a temperature sensor 734 that senses, detects and/or otherwise determines a temperature of the engine 712, the battery 714 and/or the surrounding ambient temperature; and, a display 740 or other suitable visual, audible or humanly perceivable warning indicator. Suitably, the controller 730 regulates or otherwise controls operation of the relays 736 and 738 and/or the display 740 in response to the SOC or condition of the battery 714 as detected by the sensor 732. As shown, the SOC or condition of the battery 714 is obtained by the controller 730 from the sensor 732 which is electrically and/or otherwise operatively connected to the battery 714 so as to sense and/or otherwise detect the SOC and/or condition of the battery 714. More specifically, for example, the controller 730 receives a signal representative of a condition or SOC of the battery 714 from the sensor 732. In the illustrated embodiment, the sensor 732 is electrically connected to the battery 714 for determining the SOC and/or condition of the battery 714 and generating an SOC signal representative thereof to send to the controller 730. The SOC signal can be one or more signals that indicate the condition or SOC of the battery 714. The condition can be a value indicating the charge remaining in the battery 714 relative to a scale ranging between a low end where no charge remains in the battery 714 and a high end where the battery 714 is fully charged. In one suitable embodiment, the SOC signal indicates the condition of the battery 714 as related to its overall charge capacity (i.e., a value or percentage of a maximum SOC of the battery 714). In another exemplary embodiment, the SOC signal indicates the percentage of maximum electrical energy output of the battery 714. In either event, suitably the sensor 732 measures or otherwise detects any one or more of a variety of different factors and/or parameters from which the battery's SOC is calculated or otherwise determined. These factors or parameters suitably include but are not limited to, the battery voltage, battery current, charge balance, etc. In practice, any of a variety of well known or otherwise appropriate methods and/or algorithms may optionally be used to calculate or determine the SOC from the respective parameters measured or otherwise obtained by the sensor 732.

In addition to the SOC signal received from the SOC sensor 732, the controller 730 also receives a temperature signal or measurement obtained from the temperature sensor 734. Suitably, the controller 730 uses this temperature signal or measurement to calculate, adjust and/or otherwise determine the values for a plurality of different thresholds. Moreover, the controller 730 also optionally monitors and/or otherwise receives a signal indicative of the state of the ignition switch 720, i.e., ON or OFF. In turn, the controller 730 selectively takes one or more appropriate remedial actions to protect the battery 714 from excessive discharge by comparing the SOC obtained from the SOC sensor 732 to the respective determined thresholds. For example, suitable remedial actions include: (i) selectively disconnecting one or more of the loads 716 and/or 718 from the battery 714 or otherwise cutting-off power from the battery 714 to one or more of the loads 716 and/or 718, e.g., via appropriate control of the respective relays 736 and/or 738; and/or, (ii) selectively output via the display 740 a suitable warning indication regarding the SOC or condition of the battery and/or other indication of the remedial actions taken by the controller 730. In one suitable embodiment, each threshold value is calculated as a corresponding function of the measured or otherwise obtained temperature. For example, to determine each individual threshold the controller 730 optionally executes the equation THn = fn(TEMP), where THn represents the nth threshold and fn(TEMP) represents a function of the obtained temperature (TEMP) for the nth threshold. Alternately, each threshold may be given or assigned some preset or otherwise determined value in the controller 730 and the obtained temperature is used by the controller 730 to select or determine an offset amount or otherwise adjust each preset threshold value by some set or otherwise determined amount. Suitably, for any given temperature, the offset or adjustment amount may be the same for each threshold or it may vary between different thresholds. In yet another example, a look-up table (LUT) or the like may be provisioned in the controller 730 which relates nominal threshold values and temperature. Accordingly, to determine an actual threshold to which the SOC will be compared by the controller 730, the controller 730 accesses the LUT by cross-referencing a nominal threshold value with the obtained temperature, thereby retrieving the corresponding entry in the LUT to be used as the actual threshold value.

With reference now to FIGURE 8, there is shown an exemplary process 8100 for protecting the battery 714 from excessive discharge. In the illustrated example, three thresholds (namely, TH1 , TH2 and TH3) that are calculated or otherwise determined based upon the measured or otherwise obtained temperature from the temperature sensor 734 are employed to selectively trigger corresponding remedial actions by the controller 730 based upon a comparison of the SOC received from the SOC sensor 732 to the respective thresholds. It is to be appreciated, however, that in practice more or less thresholds and/or corresponding remedial actions may in fact be employed as desired for a specific application and/or implementation.

In the illustrated example, at step 8102, the controller 730 obtains the temperature signal or measurement from the sensor 734 and the SOC signal or measurement from the sensor 732. At decision step 8104, the state of the ignition switch 720 is also obtained by the controller 30 and it is determined if the state of the ignition switch 720 is ON or OFF. If the state of the ignition switch 720 is determined to be ON, then the process 8100 continues to step 8118, otherwise if the state of the ignition switch is determined to be OFF, then the process 8100 branches to step 8106.

At step 8106, the controller 730 calculates (e.g., from a function f1 ) and/or otherwise determines a value for a first threshold (TH1 ) based on the temperature (TEMP) obtained in step 8102. In turn, at step 8108, the controller 730 compares the SOC obtained in step 8102 to the threshold TH1 determined in step 8106. If the SOC has met the threshold (i.e., SOC < TH1 ), then the process 8100 branches to step 8110. At step 8110, the controller 730 turns off the power supply from the battery 714 to the load 716, e.g., via suitable control of the relay 736. Optionally, at this point the controller 730 also signals and/or otherwise controls the display 40 to output a corresponding message or other indication of the remedial action being taken, e.g., "Due to Insufficient Battery Level, Your Vehicle's Battery Management System has Forcefully Tumed-Off the Interior Lighting." Following step 8110, the process 8100 continues to step 8112. Alternately, if at decision step 8108, it is determined that the SOC has not met the threshold (i.e., SOC > TH1 ), then the process 8100 skips step 8110 and proceeds directly to step 8112.

At step 8112, the controller 730 calculates (e.g., from a function f2) and/or otherwise determines a value for a second threshold (TH2) based on the temperature (TEMP) obtained in step 8102. In turn, at step 8114, the controller 730 compares the SOC obtained in step 8102 to the threshold TH2 determined in step 8112. If the SOC has met the threshold (i.e., SOC < TH2), then the process 8100 branches to step 8116. At step 116, the controller 730 turns off the power supply from the battery 714 to the load 718, e.g., via suitable control of the relay 738. Optionally, at this point the controller 30 also signals and/or otherwise controls the display 740 to output a corresponding message or other indication of the remedial action being taken, e.g., "Due to Insufficient Battery Level, Your Vehicle's Battery Management System has Forcefully Turned-Off the +B Power Supply." Following step 81 16, the process 8100 suitably end. Alternately, if at decision step 8114, it is determined that the SOC has not met the threshold (i.e., SOC > TH2), then the process 8100 skips step 8116 and proceeds directly to the end of the process 8100.

Returning attention now to decision step 8104, if it is determined that the ignition switch 720 is in the ON state, then the process 8100 continues to step 8118. At step 8118, the controller 730 calculates (e.g., from a function f3) and/or otherwise determines a value for a third threshold (TH3) based on the temperature (TEMP) obtained in step 8102. In turn, at step 8120, the controller 730 compares the SOC obtained in step 8102 to the threshold TH3 determined in step 8118. If the SOC has met the threshold (i.e., SOC ≤ TH3), then the process 8100 branches to step 8122. At step 8122, the controller 730 signals and/or otherwise controls the display 740 to output an appropriate warning message or other indication regarding the SOC or condition of the battery 714, e.g., "BATTERY CHARGE LOW - Please Start Engine to Recharge Battery or Turn Vehicle Off to Conserve Battery Condition." Alternately, if at decision step 8120, it is determined that the SOC has not met the threshold (i.e., SOC > TH3), then the process 8100 skips step 8122 and proceeds directly to the end of the process 8100.

While one or more of the foregoing embodiments have been described with reference to the battery's SOC, it is to be appreciated that SOC is merely an exemplary parameter that sensed, measured and/or otherwise determined and accordingly used as a basis for adjusting the respective thresholds (e.g., TH1 , TH2 and TH 3). More generally and/or in alternate embodiments, other parameters indicative of and/or related to the battery's state of function (SOF) may similarly be obtained (i.e., sensed, measure and/or otherwise determined) and accordingly used as a basis for adjusting the respective thresholds. In this regard, examples of the battery's SOF include not only the battery's SOC but also the battery's cranking voltage, the internal resistance of the battery, the battery's reserve capacity, the cold cranking amperes (CCA) of the battery, the battery's health and the like. Accordingly, it is intended that the terms and/or parameters SOC and SOF when used herein may optionally be interchanged where appropriate to achieve various alternate embodiments suitable for particular desired applications.

In any event, it is to be appreciated that in connection with the particular exemplary embodiments presented herein certain structural and/or function features are described as being incorporated in defined elements and/or components. However, it is contemplated that these features may, to the same or similar benefit, also likewise be incorporated in common elements and/or components where appropriate. For example, the sensor 732 and controller 730 may suitably be integrated together. It is also to be appreciated that different aspects of the exemplary embodiments may be selectively employed as appropriate to achieve other alternate embodiments suited for desired applications, the other alternate embodiments thereby realizing the respective advantages of the aspects incorporated therein.

It is also to be appreciated that particular elements or components described herein may have their functionality suitably implemented via hardware, software, firmware or a combination thereof. For example, the controller 730 and/or sensor 732 may be implemented as appropriate hardware circuits or alternately as microprocessors programmed to implement their respective functions. Additionally, it is to be appreciated that certain elements described herein as incorporated together may under suitable circumstances be stand-alone elements or otherwise divided. Similarly, a plurality of particular functions described as being carried out by one particular element may be carried out by a plurality of distinct elements acting independently to carry out individual functions, or certain individual functions may be split-up and carried out by a plurality of distinct elements acting in concert. Alternately, some elements or components otherwise described and/or shown herein as distinct from one another may be physically or functionally combined where appropriate.

Referring now to FIGURE 9, which shows a schematic diagram of an etectric system for a vehicle 96, e.g., such an automobile or other similar automotive vehicle. As shown, the vehicle 96 includes an engine 98 (e.g., an internal combustion engine or the like) that drives the vehicle 96. The vehicle 98 is also provisioned with an electrical system including: a battery 910 which suitably provides a source of electrical power for starting the engine 98 of the vehicle 96 (e.g., by selectively providing electric power to the vehicle's ignition system (not shown)); and, one or more electric circuits or loads (not shown) that may also be selectively powered by the vehicle's battery 910. For example, the loads may include: headlights; clocks; electrically powered adjustable components such as seats, mirrors or steering columns; interior cabin lights; electric heaters for seats, mirrors, windows or the like; radios and/or other entertainment systems; electronic memories for recording radio station presets and/or user preferred seat and/or mirror positions; electronic navigation systems; electrically controlled, powered and/or assisted brakes; electrically controlled, powered and/or assisted steering; etc. Suitably, the battery 910 is a nominal 912 volt (V) battery of the type commonly employed in automobiles or may be any other type of battery, e.g., typically used in automotive and/or motor vehicle applications.

The vehicle 96 also includes an electric generator 912 (e.g., an ACG or alternator or other like device commonly known and/or employed in the automotive or motor vehicle arts) that is driven by the engine 98 to produce electric power when the engine 98 is running. In the illustrated embodiment, the ACG 912 is also operatively connected to the battery 910 and/or the aforementioned electrical loads or otherwise arranged to selectively provide electric power to the aforementioned loads and/or to charge the battery 910. That is to say, when the engine 98 of the vehicle 96 is running, the engine 98 drives the ACG 912 which in turn normally provides electric current to charge the battery 910 and/or power the various electrical loads.

Suitably, the ACG 912 is a dual output mode ACG, capable of outputting or generating electrical power at one of two selected voltages, namely, a HI voltage output (e.g., approximately 14.5 V) and a LO voltage output (e.g., approximately 12.5 V). Customarily, the operation of the ACG 912 cycles between the HI and LO voltage output modes in response to various operating conditions. More specifically, the generator 912 is the type typically employed in an automotive vehicle and under normal operating conditions the generator 912 is free to selectively operate in and/or cycle between one of the two voltage output modes, e.g., depending on the operative state of the loads and/or demand for electric power from the generator 912. For example, in a first or HI output voltage mode, the output voltage of the generator 912 is typically about 14.5 V, and in a second or LO output voltage mode, the output voltage of the generator 912 is typically about 12.5 V. Optionally, these voltage values may vary, e.g., depending on the internal or other temperature of the generator 912. In a suitable embodiment, under normal operating conditions, when the demand for electric power is relatively high or heavy or when the battery 910 is to be charged, the generator 912 generally operates in the HI output voltage mode, and when the demand for electric power is relatively low or light or when the battery is allowed or desired to discharge, the generator 912 generally operates in the LO output voltage mode. That is to say, under normal operating conditions, the generator 912 is generally free to selectively cycle between the two modes as the electric power demanded from the generator 912 varies, e.g., due to changes in the operative states of the loads. Alternately, the ACG 912 is optionally a linear ACG that outputs an arbitrary voltage, e.g., commanded by a control unit 914.

Also illustrated in FIGURE 9, are the control unit 914, a sensor 916 (e.g., a current sensor or the like) and a ground circuit 918 (e.g., a ground wire or the like). Suitably, the sensor 916 is operatively connected to the battery 910 as shown and/or otherwise arranged under the control of the control unit 914 to selectively measure and/or otherwise obtain a value representative of the charge and/or discharge current of the battery 910. As shown, the control unit 914 is operatively connected to both the generator 912 and the sensor 916 to suitably control and/or regulate operation thereof and/or obtain readings of measurements and/or data therefrom. Suitably, as illustrated, the ground circuit 918 optionally comprises a ground wire or other conductor operatively connecting the negative terminal of the battery 910 through the sensor 916 to an electrical ground, e.g., such a frame, chassis and/or body of the vehicle 96.

Generally, the present inventive subject matter is directed to detecting an open circuit fault or high resistance fault in the ground circuit (e.g., the ground circuit 918) of a vehicle's electrical system (e.g., such as the vehicle 96). To achieve the aforementioned fault detection, the charge or discharge current from the battery 910 is directly measured, indirectly measured and/or estimated from other operating parameters of the vehicle 96. More specifically, in one suitable embodiment, just after the vehicle 96 has been started (and periodically or intermittently thereafter), the control unit 914 commands, regulates or otherwise controls the ACG 912 so as to force the ACG 912 to operate for a brief test period in the LO voltage output mode or at an arbitrarily lower voltage, or optionally, the control unit 914 turns the ACG output off altogether during the test period. In any case, at this point (i.e., during the test period), a battery discharge current larger than zero will generally be experienced or otherwise achieved. Accordingly, during the test period, the control unit 914 instructs and/or requests the battery sensor 916 to take a measurement and/or return a reading of the present battery current. The obtained battery current is then compared with an expected, estimated and/or typical value (i.e., a threshold value). If the obtained battery current value (e.g., from the sensor 916) does not meet or exceed the threshold value, then the ground circuit 18 is deemed to be compromised (i.e., in an open circuit or high resistance fault condition). Suitably, a warning or other appropriate indication of the detected fault condition may then be provided. Alternately, the ACG 912 can be commanded to operate at a higher voltage and the battery charging current can be observed to determine the respective fault condition, more specifically the difference between the previous or pretest period battery current and the present battery current during the test period.

With regard to the embodiment shown in FIGURE 9, suitably the sensor 916 directly measures the battery current. However, in other suitable embodiments, the battery current may be indirectly measured by sensing or detecting the ACG output current and vehicle's electrical load current, or alternately, the battery current may be estimated based upon ACG operating curves and knowledge of the operational status of the vehicle's electrical loads. In yet other suitable embodiment, aspects of any combination of the three techniques may be combined as appropriate.

With reference to FIGURE 10, there is shown an exemplary process 10100 for detecting an open circuit and/or high resistance fault condition in the ground circuit 918, e.g., a break or discontinuity in the ground wire or other like conductor. Suitably, the process is 10100 is executed just after or nearly after the vehicle 96 is started (e.g. as detected by activation and/or operation of the vehicle's ignition system) and/or periodically or intermittently thereafter as desired to ensure that the ground circuit 918 is not compromised during otherwise normal operation of the vehicle 96. Suitably, at a first step 10102 in the process 10100, the control unit 914 temporarily forces the ACG or generator 912 into the LO output voltage mode or optionally turns off, disables, discontinues or otherwise interrupts the output from the ACG 912 to the battery 910 altogether. For example, the control unit 914 optionally sends a suitable control or regulating signal to the ACG or generator 912 to achieve the foregoing result, in practice, this state is suitably maintained for a designated test period in which the battery discharge current is measured or otherwise obtained, e.g., at step 10104. Once the test period is completed (i.e., once the battery discharge current has been established), then the control unit 914 suitably signals or otherwise permits the ACG or generator 912 to return to a normal operational state, i.e., freely switching or cycling between HI and LO output voltage modes as appropriate (e.g., depending on the demand from the electric loads being supplied electric power thereby). As illustrated, at step 10104, the control unit 914 reads a measurement or otherwise obtains a value for the battery discharge current. For example, the battery discharge current may be measured directly by the sensor 916 during the test period and supplied to the control unit 914 therefrom. Alternately, the battery discharge current may be indirectly measured by sensing or detecting the ACG output current and the vehicle's electrical load current, or alternately, the battery discharge current may be estimated based upon ACG operating curves and knowledge of the operational status of the vehicle's electrical loads, or some combination of the aforementioned direct measurement, indirect measurements and/or estimates may be made to obtain and/or establish a value for the battery discharge current during the test period. In any event, for notation purposes, this measured, obtained or otherwise established current for the battery 910 during the test period will be referred to as IBAT herein.

At decision step 10106, the IBAT measured, obtained or otherwise established in step 10104 is compared to a threshold value (for notation purposes referred to herein as ITH), e.g., by the control unit 914. Suitably, ITH is selected, set and/or otherwise determined so as to represent a normal expected, estimated and/or typical value for IBAT under the test circumstances. As illustrated in the flow chart of FIGURE 10, if IBAT meets or exceeds ITH, then no open circuit or high resistance fault in the ground circuit 918 is deemed to have been detected, i.e., the ground circuit 918 is deemed "OK" or not compromised by an open circuit or high resistance fault as shown in box 10108. Alternately, if IBAT is below or less than ITH, then an open circuit or high resistance fault in the ground circuit 918 is deemed to have been detected, i.e., the ground circuit 18 is deemed to be compromised by an open circuit or high resistance fault as shown in box 10110, e.g., there may be a discontinuity or break in the wire or conductor. Accordingly, at step 10112, appropriate remedial action and/or a suitable warning is triggered, e.g., by the control unit 914. In one suitable embodiment, for example, a warning light, audible signal or other appropriate indictor perceivable by the vehicle operator (e.g., on the vehicle's dashboard, instrument panel or elsewhere within the vehicle cabin) is suitably activated or otherwise controlled to alert the vehicle operator of the detected fault condition in the ground circuit 918. As can be appreciated from the foregoing description, FIGURE 10 illustrates an exemplary process which is generally applicable when a dual output mode ACG 912 is being employed. In an alternate embodiment, e.g., when a linear ACG 912 is being employed, the exemplary process illustrated in FiGURE 11 may optionally be employed. With reference to FIGURE 11 , there is shown another exemplary process 11200 for detecting an open circuit and/or high resistance fault condition in the ground circuit 918, e.g., a break or discontinuity in the ground wire or other like conductor. Suitably, the process is 11200 is executed just after or nearly after the vehicle 96 is started (e.g. as detected by activation and/or operation of the vehicle's ignition system) and/or periodically or intermittently thereafter as desired to ensure that the ground circuit 918 is not compromised during otherwise normal operation of the vehicle 96.

As illustrated, at step 11201 , the control unit 914 reads a measurement or otherwise obtains a pre-test period value for the battery current. For example, the battery current may be measured directly by the sensor 916 and supplied to the control unit 914 therefrom. Alternately, the battery current may be indirectly measured by sensing or detecting the ACG output current and the vehicle's electrical load current, or alternately, the battery current may be estimated based upon ACG operating curves and knowledge of the operational status of the vehicle's electrical loads, or some combination of the aforementioned direct measurement, indirect measurements and/or estimates may be made to obtain and/or establish a value for the pre-test period battery current. In any event, for notation purposes, this measured, obtained or otherwise established current for the battery 10 will be referred to as IBAT1 herein.

Suitably, at step 11202 in the process 11200, the control unit 914 temporarily forces the ACG or generator 912 to vary its output voltage by some selected, set or otherwise determined amount. That is to say, the ACG 912 is commanded by the control unit 914 so as to make the output voltage (VOUT) of the ACG 912 change by a known amount (ΔV). For example, the control unit 914 optionally sends a suitable control or regulating signal to the ACG or generator 912 to achieve the foregoing result. In practice, this state is suitably maintained for a designated test period in which the battery current is measured or otherwise obtained, e.g., at step 11204. Once the test period is completed (i.e., once the test period battery current has been established), then the control unit 914 suitably signals or otherwise permits the ACG or generator 912 to return to a normal operational state. As illustrated, at step 11204, the control unit 914 reads a measurement or otherwise obtains a value for the battery current during the test period. For example, the battery current may be measured directly by the sensor 916 during the test period and supplied to the control unit 914 therefrom. Alternately, the battery current may be indirectly measured by sensing or detecting the ACG output current and the vehicle's electrical load current, or alternately, the battery current may be estimated based upon ACG operating curves and knowledge of the operational status of the vehicle's electrical loads, or some combination of the aforementioned direct measurement, indirect measurements and/or estimates may be made to obtain and/or establish a value for the battery current during the test period. In any event, for notation purposes, this measured, obtained or otherwise established current for the battery 910 during the test period will be referred to as IBAT2 herein.

At decision step 11206, the difference between IBAT1 and IBAT2 measured, obtained or otherwise established in steps 1 1201 and 11204 is compared to a threshold value (for notation purposes referred to herein as ITH), e.g., by the control unit 914. Suitably, ITH is selected, set and/or otherwise determined so as to represent a normal expected, estimated and/or typical difference under the test circumstances. As illustrated in the flow chart of FIGURE11 , if the difference meets or exceeds ITH, then no open circuit or high resistance fault in the ground circuit 918 is deemed to have been detected, i.e., the ground circuit 918 is deemed "OK" or not compromised by an open circuit or high resistance fault as shown in box 1 1208. Alternately, if the difference is below or less than ITH, then an open circuit or high resistance fault in the ground circuit 918 is deemed to have been detected, i.e., the ground circuit 918 is deemed to be compromised by an open circuit or high resistance fault as shown in box 11210, e.g., there may be a discontinuity or break in the wire or conductor. Accordingly, at step 11212, appropriate remedial action and/or a suitable warning is triggered, e.g., by the control unit 914. In one suitable embodiment, for example, a warning light, audible signal or other appropriate indictor perceivable by the vehicle operator (e.g., on the vehicle's dashboard, instrument panel or elsewhere within the vehicle cabin) is suitably activated or otherwise controlled to alert the vehicle operator of the detected fault condition in the ground circuit 918.

It is to be appreciated that in connection with the particular exemplary embodiments presented herein certain structural and/or function features are described as being incorporated in defined elements and/or components. However, it is contemplated that these features may, to the same or similar benefit, also likewise be incorporated in common elements and/or components where appropriate. For example, the sensor 916 and controller 914 may suitably be integrated together. It is also to be appreciated that different aspects of the exemplary embodiments may be selectively employed as appropriate to achieve other alternate embodiments suited for desired applications, the other alternate embodiments thereby realizing the respective advantages of the aspects incorporated therein.

It is also to be appreciated that particular elements or components described herein may have their functionality suitably implemented via hardware, software, firmware or a combination thereof. For example, the controller 914 and/or sensor 916 may be implemented as appropriate hardware circuits or alternately as microprocessors programmed to implement their respective functions. Additionally, it is to be appreciated that certain elements described herein as incorporated together may under suitable circumstances be stand-alone elements or otherwise divided. Similarly, a plurality of particular functions described as being carried out by one particular element may be carried out by a plurality of distinct elements acting independently to carry out individual functions, or certain individual functions may be split-up and carried out by a plurality of distinct elements acting in concert. Alternately, some elements or components otherwise described and/or shown herein as distinct from one another may be physically or functionally combined where appropriate.

Referring now to FIGURE 12, which shows a schematic diagram of an engine idle speed control system for a vehicle 1210, e.g., such as an automobile or other similar automotive vehicle. As shown, the vehicle 1210 includes an engine 1212 (e.g., an internal combustion engine or the like) that drives the vehicle 1210. The vehicle 1210 is also provisioned with an electrical system including: a battery 1214 which suitably provides a source of electrical power for starting the vehicle 1210; and, one or more electric circuits or loads that may also be selectively powered by the vehicle's battery 1214. As illustrated in FIGURE 12, the loads are collectively represented by box 1216 and may include, e.g., headlights, clocks, electrically powered adjustable components such as seats, mirrors or steering columns, interior cabin lights, electric heaters for seats, mirrors, windows or the like, radios and/or other entertainment systems, etc. Suitably, the battery is a nominal 12 volt (v) battery of the type commonly employed in automobiles or may be any other type of battery, e.g., typically used in automotive applications.

In the illustrated embodiment, the vehicle 1210 also includes an ACG 1218 or other like device that is driven by the engine 1212 to produce electric power when the engine 1212 is running. For example, the ACG 1218 may be any type of alternator or other current generator commonly known and/or employed in the automotive arts. Suitably, the ACG 1218 is arranged to selectively provide electric power to the loads 1216 and/or to charge the battery 1214. The amount of electric power produced and/or output by the ACG 1218 is generally dependent upon the rotational speed at which the ACG 1218 is driven and accordingly upon the rotational speed of the engine 1212 which is driving the ACG 1218. That is to say, when the engine 1212 is operating at a relatively lower rpm, then the output of the ACG 1218 is correspondingly lower and when the engine 1212 is operating at a relatively higher rpm, then the output of the ACG 1218 is correspondingly higher.

Suitably, the vehicle 1210 also includes an engine idle speed controller 1220 that regulates and/or otherwise controls the idle speed of the engine 1212 in response to or as a function of the SOC of the battery 1214. As shown, the SOC of the battery 1214 is obtained by the controller 1220 from a sensor unit or sensor 1222 operatively connected to the battery 1214 so as to sense and/or otherwise detect the SOC of the battery 1214.

More specifically, for example, the controller 1220 receives a signal representative of a condition or SOC of the battery 1214 from the sensor 1222. In the illustrated embodiment, the sensor 1222 is electrically connected to the battery 1214 for determining the condition of the battery 1214 and generating the SOC signal representative thereof to send to the controller 1220. The SOC signal can be one or more signals that indicate the condition or SOC of the battery 1214. The condition can be a value indicating the charge remaining in the battery 1214 relative to a scale ranging between a low end where no charge remains in the battery 1214 and a high end where the battery 1214 is fully charged. In one suitable embodiment, the SOC signal indicates the condition of the battery 1214 as related to its overall charge capacity (i.e., a value or percentage of a maximum SOC of the battery 1214). In another exemplary embodiment, the SOC signal indicates the percentage of maximum electrical energy output of the battery 1214.

In either event, suitably the sensor unit or sensor 1222 measures or otherwise detects any one or more of a variety of different factors and/or parameters from which the battery's SOC is calculated or otherwise determined. These factors or parameters suitably include but are not limited to, the battery voltage, battery current, charge balance, battery temperature, etc. Any of a variety of well known or otherwise appropriate methods and/or algorithms may optionally be used to calculate or determine the SOC from the respective parameters measured or otherwise obtained by the sensor 1222.

With additional reference to FIGURE 13, the controller 1220 controls the idle speed of the engine 1212 based on and/or in response to the SOC signal received from the sensor 1222. Suitably, the engine idle speed is adjusted via any one or more of a variety of well known and/or appropriate techniques, e.g., by regulating the throttle or fuel injection, adjusting the fuel to air ratio, or controlling other engine speed determining factors and/or parameters. Depending on the battery SOC, the engine idle speed is suitably adjusted by the controller 1220 to a selected or determined value between a minimum idle speed (e.g., 600 rpm) and a maximum idle speed (e.g., 1 100 rpm). Generally, in accordance which a prescribed algorithm or function, the controller 1220 sets or selects a relatively higher engine idle speed in response to a relatively lower SOC and conversely sets or selects a relatively lower engine idle speed in response to a relatively higher SOC. For example, as shown in FIGURE 13, the minimum engine idle speed is set when the battery SOC is at or around 100% and the maximum engine idle speed is set when the battery SOC is at or around 80%.

In addition to controlling the engine idle speed based on the SOC, the controller 1220 is also programmed or otherwise provisioned to skip or avoid one or more selected engine idle speeds or ranges that have been identified as a cause of: unwanted noise in the vehicle 1210; unwanted vibrations in the vehicle 1210; undesirable emissions control; and/or undesirable driveline torque. In practice, one or more idle speeds or ranges are first identified at which the unwanted effects are generated and/or at which the undesired results manifest. Suitably, these idles speeds and/or ranges are identified, e.g., via testing, modeling or otherwise. Accordingly, the idle adjustment and/or control algorithm utilized by the controller 1220 is then modified or designed to skip or otherwise avoid these identified idle speeds or ranges. For example, as shown in FIGURE 13, the engine idle speeds in the ranges from i to j and from m to n may have been identified as causing unwanted noise or vibrations at some location in the vehicle 1210 due to resonance or otherwise or these ranges may have been identified as resulting in suboptimal emissions control and/or an undesired increase in driveline or transmission torque and/or losses. Therefore, as the SOC approaches the values x or y, the aforementioned engine idle speeds or ranges are avoided or skipped by the controller 1220. As can be appreciated, the skipping of selected engine idle speeds or ranges is reflected by the corresponding discontinuities in the illustrated graph. Suitably, the controller 1220 calculates the engine idle speed as a function of the SOC received from the sensor 1222. That is to say, the controller 1220 may optionally execute an equation such as IS = f(SOC), where IS represents the calculated engine idle speed and f(SOC) represents a function of the SOC received from the sensor 1222. The function f optionally maps a particular input SOC to a desired corresponding engine idle speed. For example, FIGURE 13 illustrates one form of a suitable function f. Of course, alternately, the function f may take any other desired or appropriate form for the particular application or vehicle in question. In another alternate embodiment, the controller 1220 is provisioned with a look-up table (LUT) or the like that relates battery SOC to engine idle speed. Accordingly, the controller 1220 selects an engine idle speed from the LUT based on the SOC signal received from the sensor 1222.

Of course, the idle speed, SOC and/or other values illustrated in FIGURE 13 are merely examples. It is to be appreciated that in practice the actual values may be varied to suit particular applications as desired.

In any event, it is to be appreciated that in connection with the particular exemplary embodiments presented herein certain structural and/or function features are described as being incorporated in defined elements and/or components. However, it is contemplated that these features may, to the same or similar benefit, also likewise be incorporated in common elements and/or components where appropriate. For example, the sensor 1222 and controller 1220 may suitably be integrated together. It is also to be appreciated that different aspects of the exemplary embodiments may be selectively employed as appropriate to achieve other alternate embodiments suited for desired applications, the other alternate embodiments thereby realizing the respective advantages of the aspects incorporated therein.

It is also to be appreciated that particular elements or components described herein may have their functionality suitably implemented via hardware, software, firmware or a combination thereof. For example, the controller 1220 and/or sensor 1222 may be implemented as appropriate hardware circuits or alternately as microprocessors programmed to implement their respective functions. The present specification also describes a system and/or method that overcomes the above-mentioned drawbacks by providing a device (e.g., a relay or other like switch) along with a suitable controller to automatically cutoff power from a vehicle battery to one or more selected circuits or loads upon detecting that one or more triggering conditions have been met or satisfied. For example, the triggering condition is suitably a set or otherwise determined number of ignition cycles. That is to say, the controller suitably monitors ignition cycles, and after a predetermined number of ignition cycles have been detected, the controller automatically trips or otherwise controls the relay to cut the power from the battery to one or more selected circuits or loads without having to remove the corresponding fuse. Suitably, the number of ignition cycles at which the controller trips the relay is selected or set to substantially match the number of ignition cycles that are executed or scheduled to be executed in connection with testing procedures implemented at or about the time of manufacturing. Accordingly, without having to manually or physically remove or disconnect the fuse, at the end of the testing - presuming the scheduled ignition cycles have in fact been executed - the battery is automatically isolated from the otherwise current drawing loads insomuch as the controller will have tripped the relay cutting power from the battery to the selected loads or circuits. To operatively reconnect the battery to the selected loads and/or circuits after the relay has been initially tripped following the manufacture associated testing of the vehicle, the relay is simply reset at the time desired. Suitably, a designated control sequence (e.g., depressing a particular combination of buttons on the vehicle's instrument panel and/or otherwise manipulating selected operator controls in a particular order and/or combination) prompts the relay controller to reset the relay. Alternately, a diagnostic tool or other device that interfaces with the vehicle's main computer or control system allows a technician or other suitable individual to signal the relay controller to reset the relay. Suitably, the same routine or a similar technique is optionally employed to disable the controller from repeatedly tripping the relay each time the particular number of ignition cycles are executed. In this manner, the particular load or loads do not continue to be periodically isolated from the vehicle battery during the intended normal operation of the vehicle, e.g., by the customer.

Referring now to FIGURE 14, which shows a schematic diagram of a vehicle's electrical system including a storage battery 1410 that selectively supplies electric power and/or current to an electrical circuit or load 1412. Also shown in FIGURE 14 is a fuse 1414 or other similar device through which the electric power and/or current is delivered to the load 1412 from the battery 1410. Suitably, the fuse 1414 protects the load 1412 from receiving excessive electrical power or current.

As shown in FIGURE 14, a device such as a relay 1416 or other suitable switch or the like is also arranged between the battery 1410 and load 1412, e.g., in series with the fuse 1414. Under the control of a controller 1418, the relay 1416 is selectively opened and closed. In its open state, the relay 1416 disconnects or otherwise isolates the load 1412 from the battery 1410 so that current or electric power is not drawn by the load 1412 from the battery 1410. That is to say, in practice, when the controller 1418 detects a selected condition or otherwise determines that certain criteria are met, the controller 1418 sends a suitable control signal to the relay 1416. In response to the control signal, the relay 1416 is tripped or otherwise set to its open state thereby cutting-off the delivery of electric power or current from the battery 1410 to the load 1412. Alternately, in its closed state, the relay 1416 operatively connects the load 1412 to the battery 1410 so that electric power and/or current can be delivered from the battery 1410 to the load 1412. Notably, in accordance with the illustrated embodiment, isolation of the load 1412 from the battery 1410 can be automatically achieved via the relay 1416 without physical removal or manual disconnection of the fuse 1414.

Suitably, the controller 1418 regulates or otherwise controls operation of the relay 1416 in response to one or more triggering conditions having been detected and/or selected criteria having been met. For example, in the illustrated embodiment, the controller 1418 trips or otherwise switches the relay 1416 from its closed state to its open state upon the detection of a set or otherwise determined number of ignition cycles being detected. As shown in FIGURE 14, the vehicle includes an ignition system 1420 for selectively starting and stopping an engine 1422 of the vehicle. In the illustrated embodiment, the ignition system 1420 is suitably monitored and/or an appropriate signal is otherwise provided therefrom to a counter 1424 or the like which in turn records or otherwise counts the number of ignition cycles (i.e., engine starts and stops) that are executed by the ignition system 1420. Alternately, a detector 1426 (e.g., a vibration or sound sensor or other suitable sensor) may be arranged with respect to the engine 1422 to provide the counter 1424 with an indication of the engine starts and stops.

In either case, the controller 1418 is suitably provisioned with a set or otherwise determined threshold value and also receives or otherwise obtains the number of ignition cycles registered or recorded by the counter 1424. Accordingly, the controller 1418 compares the number of ignition cycles supplied by the counter 1424 to the threshold. If the number of ignition cycles meets or is equal to the threshold, then the controller 1418 trips or otherwise sets the relay 1416 to its open state. Otherwise, if the number of ignition cycles is below or less than the threshold, then the controller 1418 does not trip or otherwise maintains the relay 1416 in its closed state. Suitably, the threshold is selected or set to substantially match the number of ignition cycles that are normally executed or scheduled to be executed in connection with testing procedures implemented at or about the time of manufacturing. Accordingly, at the end of the testing - presuming the scheduled ignition cycles have in fact been executed - the load 1412 is automatically isolated from the battery 1410 without having to physically remove or manually disconnect the fuse 1414.

With reference to FIGURE 15, an exemplary process 15100 is illustrated for automatically disconnecting or isolating the load 1412 from the battery 1410 following the completion of the vehicle's manufacture associated testing. Please note that herein the following notation is used to represent the corresponding parameters: NIC represents the number of ignition cycles recorded or counter by the counter 1424, and TH represents the threshold value provisioned for the controller 1418. Suitably, as indicated in box 15102, at the beginning of the process

15100, the relay 1416 is initially in its closed state and the counter 1424 is set to zero (i.e., NIC = 0). If for some reason, the relay 1416 is not already in its closed state and/or the counter 1424 does not register zero ignition cycles, then the relay 1416 may optionally be set to its closed state and/or the counter 1424 initialized to zero via the process described below with respect to FIGURE 16. In either case, these initial conditions are suitably set or otherwise realized prior to the initiation of testing. The remainder of the process 15100 is thereafter executed during the test phase of manufacture which generally includes a scheduled number of ignition cycles. At decision step 15104, it is determined if an ignition cycle has been detected. For example, this may be achieved via suitable monitoring of the ignition system 1420 or via the detector 1426. If no ignition cycle is detected, then the process 100 loops back to again execute step 15104. In this manner, step 15104 is repeated until an ignition cycle is detected. Alternately, if an ignition cycle is detected, then the process 15100 continues to step 15106 where the counter 1424 is incremented or advanced in response to the detected ignition cycle (i.e., NIC = NIC + 1 ). In this manner, the counter 1424 records or otherwise maintains a running total of the number of detected ignition cycles. The number of detected ignition cycles (NIC) is in turn provided by the counter 1424 to the controller 1418, and at decision step 15108, the controller 1418 compares the number of ignition cycles obtained from the counter 1424 to the provisioned threshold. Suitably, the threshold is selected or set to reflect the number of ignition cycles that are scheduled or designated for the particular test phase in question. If the number of ignition cycles obtained from the counter 1424 has not yet reached the threshold (i.e., NIC < TH), then the process 15100 loops back to step 15104 to continue detection of ignition cycles. Otherwise, if the number of ignition cycles obtained from the counter 1424 has reached the threshold (i.e., NIC = TH), then the process 100 continues to step 15110 where the controller 1418 trips or otherwise switches the relay 1416 from its closed state to its open state thereby disconnecting or isolating the load 1412 from the battery 1410.

As can be appreciated, presuming the scheduled or designated number of ignition cycles are in fact executed during the testing phase in question, then in accordance with the illustrated process 15100, the load 1412 is disconnected or isolated from the battery 1410 automatically upon completion of the testing, i.e., without resorting to manual removal or physical disconnection of the fuse 1414. Accordingly, the vehicle is ready to be shipped and/or stored without concern that during this generally idle time period the charge in the battery 1410 will undesirably be depleted due to current draw from the load 1412.

In another suitable embodiment, the relay 1416 may also optionally be manually tripped or set to its open state, e.g., in case the scheduled number of ignition cycles are not executed during the manufacture associated testing or for other reasons. That is to say, a technician or other individual may selectively operate the controller 1418 and/or relay 1416 in a deliberate fashion so as to switch the relay 1416 to its open state thereby disconnecting or otherwise isolating the load 1412 from the battery 1410. For example, a suitable "trip relay" signal or instruction is optionally generated in response to a manual operation or user input provided by a technician or other individual, e.g., such as entering a designated control sequence via the operator controls. That is to say, depressing a particular combination of buttons on the vehicle's instrument panel, steering wheel or console and/or otherwise manipulating selected operator controls in a particular order and/or combination optionally results in the trip relay signal or instruction being generated and sent to the controller 1418. Alternately, a diagnostic tool or the like which selectively interfaces with the vehicle's central processing unit or computer control system can be used by a technician or other like individual to generate and/or send the trip relay signal or instruction to the controller 1418. Suitably, upon receiving the trip relay signal or instruction, the controller 1418 complies accordingly. Alternately, the trip relay signal or instruction may be provided directed to the relay 1416 which behaves accordingly. In either event, suitably, this manual operation and/or control of the relay 1416 allows for added flexibility during manufacture and thereafter. For example, to better appreciate the benefit of such a feature, let us assume that after manufacture of the vehicle, testing indicates that repairs should be made. During the repairs and/or retesting, it may be the case that the load 1412 is operatively reconnected to the battery 1410 (e.g., via the process described below with reference to FIGURE 16). Accordingly, it may be beneficial to have a direct manner in which to selectively trip the relay 1416 without having to execute the prescribed number of ignition cycles. In this manner, the vehicle may again be made ready for shipping and/or storage without concern that during this generally idle time period the charge in the battery 1410 will undesirably be depleted due to current draw from the load 1412.

Of course, however, it is generally desirable to operatively reconnect the load 1412 to the battery 1410 once the vehicle is ready for normal use, e.g., just prior to delivery to a customer. Moreover, it is generally undesirable during the intended normal operation or use of the vehicle, e.g., by the customer, to have the load 1412 repeatedly disconnected or isolated from the battery 1410 each time the designated number of ignition cycles is detected. Accordingly, the exemplary process 16200 illustrated in FIGURE 16 is optionally executed to prepare the vehicle for normal operation, e.g., the process 16200 may optionally be executed at or about the time the vehicle is delivered to the customer.

As illustrated in FIGURE 16, the process 16200 begins with decision step 16202 where it is determined if the controller 1418 detects or otherwise receives a reset signal. Suitably, the reset signal is generated in response to a vehicle operator entering a designated control sequence via the operator controls. That is to say, depressing a particular combination of buttons on the vehicle's instrument panel, steering wheel or console and/or otherwise manipulating selected operator controls in a particular order and/or combination optionally results in the reset signal being generated and sent to the controller 1418. Alternately, a diagnostic tool or the like which selectively interfaces with the vehicle's central processing unit or computer control system can be used by a technician or other like individual to generate and/or send the reset signal to the controller 1418. In either case, if the controller 1418 does not detect or receive the reset signal, then the process 16200 loops back to repeat step 16202. In this manner, step 16202 is repeated until the reset signal is received or detected by the controller 1418. Otherwise, if the controller 1418 does detect or receive the reset signal, then the process 16200 continues to step 16204. At step 16204, in response to the receipt and/or detection of the reset signal, the controller 1418 resets the relay 1416 to its closed stated, thereby operatively reconnecting the load 1412 to the battery 1410 so that electric power and/or current can again be received by the load 1412 from the battery 1410. Optionally, at step 16206, the controller 1418 is also disabled so that a subsequent number of ignition cycles does not again result in the load 1410 being disconnected and/or isolated from the battery 1410. That is to say, having disabled the controller 1418, the relay 1416 will remain in its closed state even if the threshold number of ignition cycles are again experienced during the intended normal operation and/or use of the vehicle. In another suitable embodiment, resetting the relay 1416 and/or disabling the controller 1418 is also achieved by again monitoring ignition cycles. More specifically, if the detected number of ignition cycles meets or exceeds a second determined threshold (THreset) (i.e., that is over and above the first threshold TH), then the relay 1416 is optionally reset (i.e., switch to its closed state) and the controller 1418 is optionally disabled. Suitably, THreset is sufficiently greater than TH so as to guard against inadvertent resetting of the relay 1416 and/or disabling the controller 1418, e.g., in connection with the manufacture associated testing. To better understand the benefit of this feature, let us assume that the controller 1418 has automatically or otherwise tripped the relay 1416 (i.e., set the relay to its open state so as to operatively disconnect the load 1412 from the battery 1410), e.g., due to the number of ignition cycles having first reached the threshold TH during the manufacture associated testing. A some later time, e.g., upon delivery of the vehicle to a customer, let us assume that perhaps the dealer has forgotten to reset the relay 1416 and/or disable the controller 1418. Nevertheless, if there is detected an additional number of ignition cycles being executed over and above the threshold TH, e.g., so as to reach the second threshold THreset, then the relay 1416 is optionally reset (i.e., switched from the open state to the closed state) and the controller 1418 is optionally disabled. Accordingly, the load 1412 is automatically reconnected to the battery 1410 and the controller 1418 disabled as desired for the intended normal operation or use of the vehicle by the customer or other operator.

It is to be appreciated that in connection with the particular exemplary embodiments presented herein certain structural and/or function features are described as being incorporated in defined elements and/or components. However, it is contemplated that these features may, to the same or similar benefit, also likewise be incorporated in common elements and/or components where appropriate. For example, the counter 1424 may suitably be integrated in the controller 1418. It is also to be appreciated that different aspects of the exemplary embodiments may be selectively employed as appropriate to achieve other alternate embodiments suited for desired applications, the other alternate embodiments thereby realizing the respective advantages of the aspects incorporated therein. It is also to be appreciated that particular elements or components described herein may have their functionality suitably implemented via hardware, software, firmware or a combination thereof. For example, the controller 1418 and/or counter 1424 may be implemented as appropriate hardware circuits or alternately as microprocessor programmed to implement their respective functions. Additionally, it is to be appreciated that certain elements described herein as incorporated together may under suitable circumstances be stand-alone elements or otherwise divided.

Referring now to FIGURE 17, which shows a schematic diagram of an electric generator control system for a vehicle 1710, e.g., such an automobile or other similar automotive vehicle. As shown, the vehicle 1710 includes an engine 1712 (e.g., an internal combustion engine or the like) that drives the vehicle 1710. The vehicle 1710 is also provisioned with an electrical system including: a battery 1714 which suitably provides a source of electrical power for starting the vehicle 1710; and, one or more electric circuits or loads that may also be selectively powered by the vehicle's battery 1714. As illustrated in FIGURE 17, the loads are collectively represented by box 1716 and may include, e.g., headlights, clocks, electrically powered adjustable components such as seats, mirrors or steering columns, interior cabin lights, electric heaters for seats, mirrors, windows or the like, radios and/or other entertainment systems, electronic memories for recording radio station presets and/or user preferred seat and/or mirror positions, electronic navigation systems, etc. Suitably, the battery is a nominal 1712 volt (v) battery of the type commonly employed in automobiles or may be any other type of battery, e.g., typically used in automotive applications.

The vehicle 1710 also includes an electric generator 1718 (e.g., an ACG or alternator or other like device commonly known and/or employed in the automotive arts) that is driven by the engine 1712 to produce electric power when the engine 1712 is running. In the illustrated embodiment, the ACG 18 is arranged to selectively provide electric power to the loads 1716 and/or to charge the battery 1714.

Suitably, the generator 1718 is the type typically employed in an automotive vehicle and under normal operating conditions (i.e., when the battery SOC is at or near a desired level or within a desired range) the generator 1718 is free to selectively operate in and/or cycle between one of two voltage output modes, e.g., depending on the operative state of the loads 1716 and/or demand for electric power from the generator 1718. For example, in a first or HI output voltage mode, the output voltage of the generator 1718 is typically about 14.5 V, and in a second or LO output voltage mode, the output voltage of the generator 1718 is typically about 12.5 V. Optionally, these voltage values may vary, e.g., depending on the internal or other temperature of the generator 1718. In a suitable embodiment, under normal operating conditions, when the electric power demand is relatively high or heavy, the generator 1718 generally operates in the HI output voltage mode, and when the electric power demand is relatively low or light, the generator 1718 generally operates in the LO output voltage mode. That is to say, under normal operating conditions, the generator 1718 is generally free to selectively cycle between the two modes as the electric power demanded from the generator 1718 varies, e.g., due to changes in the operative states of the loads 1716.

In another embodiment, the generator responds to load requirements by providing an output based on particular requirements of the loads 16 and/or battery 14. The generator 18 receives a strength of charge value and a battery health value from the battery sensor 22 in addition to a temperature value of the battery 14. Previous embodiments have operated under the assumption that the temperature of the controller is correlated to the temperature of the battery. This, however, might not always be true. Accordingly, in contrast to the previous embodiment, there is no reliance on the temperature of the generator 18 to provide an appropriate controller output.

The controller 20 utilizes a predetermined algorithm to compare a charging voltage from the sensor 22 with an output from a charge/discharge logic algorithm to relate a particular output for the generator 18. The charge/discharge logic algorithm receives the strength of charge and the battery health values from the battery sensor 22. The algorithm calculates a value that is commensurate with any number of factors including vehicle model, battery type, battery chemistry, etc. In this manner, a determination can be made as to whether charging is warranted and, if so, the voltage level associated therewith.

The logic algorithm output is compared to a charging voltage value from the battery sensor 22. The charging voltage value includes voltage compensation as it relates to the temperature of the battery 14. Once this comparison is made, an output is sent to the generator 18 to provide an appropriate linear charge to accommodate the requirements of the loads 16 and battery 18. In this manner, the generator 18 can provide an appropriate charge to the load 16 based on actual battery temperature in addition to battery strength of charge and health. It is to be appreciated that the output of the controller 20 in concert with the second embodiment described above can utilize both a high and a low output voltage modes. The linear output of the generator to the battery can be applied during a state when the strength of charge of the battery is outside both the high and low threshold levels. The high/low set points can be based on any number of factors including vehicle fuel economy, battery type and/or battery model. Communication from the controller 20 to the generator 18 can be facilitated via substantially any protocol or standard including transistor-transistor logic, 24 volt DC, serial output, etc. In one approach, the communication utilized between the controller 20 and the generator 18 is dictated by the protocol of the generator 18. The generator can have a plurality (e.g., 256, 512, etc.) of distinct levels related to particular load requirements. In this manner, the output of the generator 18 is not restricted to one of two levels (e.g., high/low). Instead, the generator 18 can output a plurality of disparate voltages that correlate to specific variable load requirements.

The controller 20 can additionally include a particular voltage setting to provide an appropriate output for the generator 18. The voltage can be set as either a high mode or a low mode, which is dependent on the particular battery type. In one example, the high mode is equivalent to an optimal battery charging voltage and a low mode is equal to the optimal battery charging voltage minus a constant (such as approximately 1.7 volts). The value of the optimal battery charging voltage and the constant can be battery specific and vary from one manufacture type and/or model to another. Suitably, the generator control system includes a controller 1720 that regulates and/or otherwise controls the output voltage of the generator 1718 in response to the SOC of the battery 1714. As shown, the SOC of the battery 1714 is obtained by the controller 1720 from a sensor unit or sensor 1722 that is electrically and/or otherwise operatively connected to the battery 1714 so as to sense and/or otherwise detect the SOC of the battery 1714. That is to say, in the illustrated embodiment, the generator control system also suitably includes a SOC sensor 1722 that senses, detects and/or otherwise determines a SOC or condition of the battery 1714 and communicates this information to the controller 1720 which in turn controls the operating mode of the generator 1718 based on the received information.

More specifically, for example, the controller 1720 receives a signal representative of a condition or SOC of the battery 1714 from the sensor 1722. In the illustrated embodiment, the sensor 1722 is electrically connected to the battery 1714 for determining the SOC and/or condition of the battery 1714 and generating an SOC signal representative thereof to send to the controller 1720. The SOC signal can be one or more signals that indicate the condition or SOC of the battery 1714. The condition can be a value indicating the charge remaining in the battery 1714 relative to a scale ranging between a low end where no charge remains in the battery 1714 and a high end where the battery 1714 is fully charged. In one suitable embodiment, the SOC signal indicates the condition of the battery 1714 as related to its overall charge capacity (i.e., a value or percentage of a maximum SOC of the battery 1714). In another exemplary embodiment, the SOC signal indicates the percentage of maximum electrical energy output of the battery 1714.

In either event, suitably the sensor 1722 measures or otherwise detects any one or more of a variety of different factors and/or parameters from which the battery's SOC is calculated or otherwise determined. These factors or parameters suitably include but are not limited to, the battery voltage, battery current, charge balance, battery temperature, etc. In practice, any of a variety of well know or otherwise appropriate methods and/or algorithms may optionally be used to calculate or determine the SOC from the respective parameters measured or otherwise obtained by the sensor 1722.

Generally, based on the SOC or condition of the battery 1714 or more specifically the SOC signal received from the sensor 1722, the controller 1720 regulates or otherwise controls the operation of the generator 1718. In particular, if the SOC is outside a set or otherwise determined range, then controller 1720 sends or otherwise provides a control signal or the like to the generator 1718 to thereby force, induce or otherwise compel the generator 1718 to operate in a particular one of the two operating modes, i.e., HI or LO. Alternately, if the SOC is within the set or determined range, then the controller 1720 allows the generator 1718 to operate normally, i.e., to freely switch or cycle between the HI and LO operating modes selectively in accordance with otherwise normal operating conditions. For example, if the SOC is at or above a first threshold (TH1 ) (e.g., approximately 98%), then the controller 1720 outputs a control signal to the generator 1718 which forces or instructs or otherwise controls the generator 1718 so that the generator 1718 operates in the LO voltage output mode. Alternately, if the SOC is at or below a second threshold (TH2) (e.g., approximately 80%), then the controller 1720 outputs a control signal to the generator 1718 which forces or instructs or otherwise controls the generator 1718 so that the generator 1718 operates in the HI voltage output mode. Otherwise, if the SOC is in-between the first and second thresholds, then in one embodiment the controller 1720 outputs no control signal to the generator 1718 thereby allowing the generator 1718 to operate in its normal manner, i.e., freely switching or cycling between the HI and LO voltage output modes. In another embodiment, if the SOC is in-between the first and second thresholds, then the controller 1720 may still output a control signal to the generator 1718 which in this instance instructs or otherwise allows the generator 1718 to operate in its normal manner, again, freely switching or cycling between the HI and LO voltage output modes.

While the values of 98% and 80% have been referred to herein with regard to the thresholds TH1 and TH2, respectively, it is to be appreciated that these values are merely examples. In practice, other suitable threshold values for TH1 and/or TH2 may be used, e.g., depending on the particular application, the specific battery type and/or as otherwise desired. For example, TH1 may optionally be in the approximate range of 98% to 102% for a VRLA (valve-regulated lead acid) or AGM (absorbent glass mat) type battery. Alternately, in the case of a flooded lead acid type battery, TH1 may optionally be in the approximate range of 100% to 110%. Suitably, the actual threshold values may depend, e.g., on the vehicle and/or electrical system parameters associated with a particular application.

With reference now to FIGURE 18, there is shown an exemplary process 18100 executed by the controller 1720 for selectively controlling the voltage output mode of the generator 1718 based upon the SOC or condition of the battery 1714 sensed or detected by the sensor 1722.

In the illustrated example, at step 18102, the controller 1720 obtains the SOC of the battery 1714 from the sensor 1722. !n turn, at decision step 18104, the controller 1720 compares the SOC obtained in step 18102 to the first threshold TH1. If the SOC is at or above the first threshold (i.e., if SOC > TH1), then the process 18100 branches to step 18106, otherwise if the SOC is below the first threshold (i.e., if SOC < TH1), then the process 18100 continues to step 18108. At step 18106, the controller 1720 outputs a control signal or the like to the generator 1718 which compels or instructs the generator 1718 to operate in the LO voltage output mode and the process 18100 then ends.

At decision step 18108, the controller 1720 compares the SOC obtained in step 18102 to the second threshold TH2. If the SOC is at or below the second threshold (i.e., if SOC < TH2), then the process 18100 branches to step 18110, otherwise if the SOC is above the second threshold (i.e., if SOC >

TH2), then the process 18100 continues to step 18112.

At step 18110, the controller 1720 outputs a control signal or the like to the generator 1718 which compels or instructs the generator 1718 to operate in the HI voltage output mode and the process 18100 then ends.

In one suitable embodiment, at step 18112, the controller 1720 outputs no control signal to the generator 1718 thereby allowing the generator 1718 to operate in its normal manner, i.e., freely switching or cycling between the HI and LO voltage output modes. Alternately, in another suitable embodiment, at step 18112, the controller 1720 outputs a control signal or the like to the generator 1718 instructing the generator 1718 to operate in its normal manner, again, freely switching or cycling between the HI and LO voltage output modes. In either case, as shown in the illustrated embodiment, following step 18112, the process 18100 ends.

Of course, in one exemplary embodiment, the controller 1720 optionally repeats the process 18100 from time-to-time in order to periodically or intermittently control the operating mode of the generator 1718 over time, e.g., as the SOC of the battery 1714 may vary from time-to-time. For example, in one suitable embodiment, the process 18100 is run by the controller 1720 each time a new or updated SOC signal is received or obtained from the sensor 1722.

FIGURE 19 illustrates an exemplary chart that corresponds to specific output levels of the strength of charge and temperature of the battery as they relate to the voltage output and state of the generator 1718. As shown, the strength of charge of the battery can force a high or a low mode to be entered by the controller 1720. In this example, when the strength of battery charge is 105% of a predetermined value, a low mode is forced. On the contrary, if the strength of charge of the battery is less than 50% a high mode can be forced, as described above. The temperature of the battery is also provided over time to illustrate the result of both a temperature increase and a temperature decrease of the battery. It is to be appreciated that other values can be employed for temperature and strength of charge of the battery 14 as they relate to voltage output and state of the generator 18.

In the first block, labeled temperature increase, as the temperature rises the voltage output of the generator 1718 decreases in value. The inverse relationship between the battery temperature and the voltage output of the generator 1718 can be described via a polynomial or other means that is battery specific. The control output of the generator 1718 can be set via an outside control source such as a signal from the engine to facilitate greater fuel economy or to reduce engine friction.

When the control output of the generator 1718 is switched from a high mode (e.g. at 14.5 volts) to a low mode (e.g. 12.8 volts) the voltage output of the generator likewise decreases by the constant amount (1.7 volts). The decrease in voltage output from the generator 1718 has a particular slew rate (e.g., 2 volts/second) to prevent undesirable loading that can cause electrical devices within the vehicle to flicker or dim to provide an irregular output to a vehicle operator. It is to be appreciated that the differential between the high and low modes of the generator 1718 can vary dependent on battery design and/or battery chemistry. In one example, the differential is generally about 1.7 volts for flooded-lead-acid battery types.

When the control of the generator is maintained in a high mode, the strength of charge of the battery 1714 can increase to greater than a 100% value of charge. If the charge is greater than a predetermined threshold, such as 100%, a low mode can be forced to provide a lower output voltage to the battery 1714. Once the low mode is entered, the output voltage of the generator 1718 likewise decreases thereby decreasing the strength of charge of the battery. Once the strength of charge of the battery is below a predetermined threshold (such as 100% value of charge) the low/high mode can be set arbitrarily by the controller 1720. Accordingly, once the low mode threshold has been passed, the control output of the generator 1718 can freely change from a high mode to a low mode and vice versa based on one or more third party control settings. Once the strength of charge of the battery decreases to a point below a predetermined threshold, a high mode output can be forced by the generator 1718. The change from the low mode to the high mode (e.g. 1.7 volts) can have a slew rate associate therewith to avoid any deleterious loading effects, as outlined above. Once the high mode output is forced the voltage output of the generator 1718 is increased to reflect the high mode output voltage value. Once the temperature of the battery 1714 decreases, the output voltage of the generator 1718 can increase in an inverse proportion to provide an appropriate charge to the battery 1714 and loads 1716. Once the battery temperature is constant at a lower value, a high output control for the generator 1718 can cause the voltage output of the generator to decrease as the strength of charge or the battery increases as the control output of the generator 1718 is set too high.

It is to be appreciated that in connection with the particular exemplary embodiments presented herein certain structural and/or function features are described as being incorporated in defined elements and/or components. However, it is contemplated that these features may, to the same or similar benefit, also likewise be incorporated in common elements and/or components where appropriate. For example, the sensor 1722 and controller 1720 may suitably be integrated together. It is also to be appreciated that different aspects of the exemplary embodiments may be selectively employed as appropriate to achieve other alternate embodiments suited for desired applications, the other alternate embodiments thereby realizing the respective advantages of the aspects incorporated therein.

It is also to be appreciated that particular elements or components described herein may have their functionality suitably implemented via hardware, software, firmware or a combination thereof. For example, the controller 1720 and/or sensor 1722 may be implemented as appropriate hardware circuits or alternately as microprocessors programmed to implement their respective functions. Additionally, it is to be appreciated that certain elements described herein as incorporated together may under suitable circumstances be stand-alone elements or otherwise divided. Similarly, a plurality of particular functions described as being carried out by one particular element may be carried out by a plurality of distinct elements acting independently to carry out individual functions, or certain individual functions may be split-up and carried out by a plurality of distinct elements acting in concert. Alternately, some elements or components otherwise described and/or shown herein as distinct from one another may be physically or functionally combined where appropriate.

In short, it will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

The exemplary embodiment has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the exemplary embodiment be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

CLAIMS:

1 . In a vehicle having an engine that drives an electric power generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle, a generator control system comprising; a sensor that detects a state of charge (SOC) of the battery; and a controller that controls a voltage output mode of the generator in response to the SOC detected by the sensor.

2. The generator control system of claim 1 wherein the generator is operable in one of two modes including a HI voltage output mode and a LO voltage output mode.

3. The generator control system of claim 2 wherein the controller provides a control signal to the generator based upon the SOC detected by the sensor, said control signal instructing the generator to operate in a selected one of the two modes when the SOC is outside a determined range, otherwise said generator being free to selectively switch between the HI and LO voltage output modes when the SOC is within the determined range.

4. The generator control system of claim 3 wherein the control signal instructs the generator to operate in the LO voltage output mode when the SOC is above a first determined threshold.

5. The generator control system of claim 4 wherein the control signal instructs the generator to operate in the HI voltage output mode when the SOC is below a second determined threshold.

6. The generator control system of claim 5 wherein the first determined threshold is in an approximate range of between 98% to 110%.

7. The generator control system of claim 6 wherein the second determined threshold is in a range of approximately 20% to 80%.

8. The generator control system of claim 7 wherein an output voltage of the generator when operating in the HI voltage output mode is approximately 14.5 volts.

9. The generator control system of claim 8 wherein the output voltage of the generator when operating in the LO voltage output mode is approximately 12.5 volts.

10. The generator control system of claim 9 wherein the generator is an alternator.

1 1. In a vehicle having an engine that drives an electric power generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle, a method for controlling a voltage output mode of the generator comprising:

(a) determining a state of charge (SOC) of the battery; and

(b) controlling a voltage output mode of the generator in response to the SOC.

12. The method of claim 11 wherein the generator is operable in one of two modes including a HI voltage output mode and a LO voltage output mode.

13. The method of claim 12 wherein an output voltage of the generator when operating in the LO voltage output mode is approximately

12.5 volts.

14. The method of claim 12 wherein the output voltage of the generator when operating in the HI voltage output mode is approximately 14.5 volts.

15. The method of claim 12, wherein step (b) comprises: compelling the generator to operate in a selected one of the two modes when the SOC is outside a determined range; and allowing said generator to freely switch between the HI and LO voltage output modes when the SOC is within the determined range.

16. The method of claim 15 wherein the step of compelling comprises: comparing the SOC to a threshold; and compelling the generator to operate in the HI voltage output mode if the SOC is less than the threshold.

17. The method of claim 16 wherein the threshold is approximately

80%.

18. The method of claim 17 wherein the step of compelling comprises: comparing the SOC to a threshold; and compelling the generator to operate in the LO voltage output mode if the SOC is greater than the threshold.

19. The method of claim 18 wherein the threshold is in an approximate range of between 98% to 110%.

20. In a vehicle having an engine that drives an electric power generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle, a system for controlling a voltage output mode of the generator comprising: means for determining a state of charge (SOC) of the battery; and means for controlling a voltage output mode of the generator in response to the SOC.

21 . The system according to claim 1 , further including: a battery; a generator that outputs power to charge the battery; a sensor that detects a health value, a voltage, a current, a temperature, and a charging voltage of the battery; and a controller that controls a voltage output mode of the generator in response to at least one of a health value, a voltage, a current, a temperature, and a charging voltage of the battery detected by the sensor, the voltage output mode is in response to the SOC and the temperature of the battery.

22. The generator control system of claim 21 , wherein the generator is operable in one of two modes including a HI voltage output mode and a LO voltage output mode.

23. The generator control system of claim 22, wherein the controller provides a control signal to the generator based upon the SOC detected by the sensor, said control signal instructing the generator to operate in a selected one of the two modes when the SOC is outside a determined range, otherwise said generator being free to selectively switch to up to 512 disparate voltage output mode when the SOC is within the determined range.

24. The generator control system of claim 23, wherein the control signal instructs the generator to operate in the LO voltage output mode when the SOC is above a first determined threshold and instructs the generator to operate in the HI voltage output mode when the SOC is below a second determined threshold.

25. The generator control system of claim 21 , wherein the controller utilizes a charge/discharge algorithm and a charging voltage value to output a control signal the generator.

26. The generator control system of claim 23, wherein the mode selected is based at least in part upon a vehicle fuel economy value and an engine friction value.

27. The generator control system of claim 22, wherein the difference between the HI mode and the LO mode is 1.7 volts.

28. The generator control system of claim 22, wherein the slew rate between the HI mode and the LO mode is about 2 volts/second.

29. The generator control system of claim 22, wherein the generator operates in the LO voltage output mode if the SOC is greater than the threshold, wherein the threshold is in an approximate range of between 98% to 110%.

30. The generator control system of claim 21 , wherein the output voltage of the generator is substantially inversely proportional to the temperature of the battery.

31. The method according to claim 1 1, further including:

(c) determining a health value, a voltage, a current, a temperature, and a charging voltage of the battery; and (d) controlling a voltage output mode of the generator in response to at least one of a health value, a voltage, a current, a temperature, and a charging voltage of the battery detected by the sensor, the voltage output mode is in response to the SOC and the temperature of the battery.

32. The method of claim 11 , wherein the generator is operable in one of two modes including a HI voltage output mode and a LO voltage output mode.

33. The method of claim 31 , step (b) comprises: compelling the generator to operate in a selected one of the two modes when the SOC is outside a determined range; and allowing said generator to freely switch to up to 512 disparate voltage output mode when the SOC is within the determined range.

34. The method of claim 31 , wherein the controller utilizes a charge/discharge algorithm and a charging voltage value to output a control signal the generator.

35. The method of claim 31 , wherein the mode selected is based at least in part upon a vehicle fuel economy value and an engine friction value.

36. The method of claim 31 , wherein the difference between the HI mode and the LO mode is 1.7 volts.

37. The method of claim 31 , wherein the slew rate between the HI mode and the LO mode is about 2 volts/second.

38. The method of claim 31 , wherein the output voltage of the generator is substantially inversely proportional to the temperature of the battery.

39. The method of claim 33, wherein the step of compelling comprises: comparing the SOC to a threshold; and compelling the generator to operate in the LO voltage output mode if the SOC is greater than the threshold, wherein the threshold is in an approximate range of between 98% to 110%.

40. The system according to claim 20: means for detecting a health value, a voltage, a current, a temperature, and a charging voltage of the battery; and means for controlling a voltage output mode of the generator in response to at least one of a health value, a voltage, a current, a temperature, and a charging voltage of the battery detected by the sensor, the voltage output mode is in a linear response to SOC of the battery.

41. The control system according to claim 1 , further including: a battery for supplying electrical power in the vehicle, wherein said controller receives a battery signal representative of a condition of said battery, an ignition key signal representative of a state of an ignition key of the vehicle, and an engine signal representative of a state of an internal combustion engine in the vehicle; at least one load selectively electrically connected to said battery by said controller in response to at least one of said battery signal, said ignition key signal and said engine signal; and an interface providing information on at least one of said battery and a connection state between said at least one load and said battery.

42. The battery control system of claim 41 wherein said at least one load is electrically disconnected from said battery by said controller in response to said battery signal, said ignition key signal and said engine signal.

43. The battery control system of claim 41 wherein said at least one load includes a first load and a second load, and wherein said controller electrically disconnects said first load from said battery when (i) said ignition key signal indicates that said ignition key is not in an ON position and (ii) said battery signal indicates said condition of said battery is below a first predetermined threshold, and further wherein said controller electrically disconnects said second load from said battery when (i) said ignition key signal indicates that said ignition key is not in said ON position and (ii) said battery signal indicates that said condition of said battery is below a second predetermined threshold, said second predetermined threshold being lower than said first predetermined threshold.

44. The battery control system of claim 43 wherein said first load is interior lighting within the vehicle and said second load is backup functions of the vehicle.

45. The battery control system of claim 43 wherein said controller commands said interface to provide a first message when said first load is electrically disconnected from said battery and commands said interface to provide a second message when said second load is electrically disconnected from said battery, said first message indicating that said first load has been disconnected from said battery and said second message indicating that said second load has been disconnected from said battery.

46. The battery control system of claim 41 further including a sensor electrically connected to said battery for determining said condition of said battery and generating said battery signal to send to said controller.

47. The battery control system of claim 41 wherein said controller commands said interface to provide a message when (i) said ignition key signal indicates that said ignition key is in an ON position, (ii) said engine signal indicates that said engine is off, and (iii) said battery signal indicates that said condition of said battery is below a predetermined threshold, said message indicating that said condition of said battery is below said predetermined threshold.

48. The battery control system of claim 41 wherein said controller electrically disconnects a first load of said at least one load from said battery when (i) said ignition key signal indicates that said ignition key is in an ON position, (ii) said engine signal indicates that said engine is on, and (iii) said battery signal indicates that that said condition of said battery is below a first predetermined threshold, and wherein said controller electrically disconnects a second load of said at least one load from said battery when (i) said ignition key signal indicates that said ignition key is in said ON position, (ii) said engine signal indicates that said engine is on, and (iii) said battery signal indicates that said condition of said battery is below a second predetermined threshold that is lower than said first predetermined threshold.

49. The battery control system of claim 41 wherein said at least one load includes a plurality of loads and said controller progressively disconnects each of said plurality of loads when (i) said ignition key signal indicates that said ignition key is in an ON position, (ii) said engine signal indicates that said engine is on, and (iii) said battery signal indicates that said condition of said battery is below a predetermined threshold that corresponds specifically to each of said plurality of loads.

50. The battery control system of claim 49 wherein said controller progressively reconnects each of said plurality of loads after being disconnected when (i) said ignition key signal indicates that said ignition key is in an ON position, (ii) said engine signal indicates that said engine is on, and (iii) said battery signal indicates that said condition of said battery is above said predetermined threshold that corresponds specifically to each of said plurality of loads.

51. The battery control system of claim 49 wherein said predetermined threshold corresponding to each of said plurality of loads is prioritized based on at least one of customer importance and energy or power consumption.

52. The method according to claim 11, further including:

(c) receiving a battery signal representative of a condition of the battery; (d) receiving an ignition key signal representative of a state of an ignition key of the vehicle;

(e) receiving an engine signal representative of a state of an internal combustion engine of the vehicle;

(f) selectively electrically connecting the plurality of loads of the vehicle to the battery based on at least one of said battery signal, said ignition key signal and said engine signal; and

(g) providing information on at least one of the battery and a connection state between at least one of the plurality of loads and the battery.

53. The battery control method of claim 52 wherein the plurality of loads of the vehicle are selectively electrically connected to the battery based on said battery signal, said ignition key signal and said engine signal.

54. The battery control method of claim 52 wherein the plurality of loads includes a first load and a second load, and wherein selectively electrically connecting the plurality of loads includes: electrically disconnecting said first load from the battery when said ignition key signal indicates that said ignition key is not in an ON position and said battery signal indicates said condition of the battery is below a first predetermined threshold; and electrically disconnecting said second load from the battery when said ignition key signal indicates that said ignition key is no in said ON position and said battery signal indicates said condition of the battery is below a second predetermined threshold.

55. The battery control method of claim 54 wherein providing information includes: displaying a first message indicating that said first load has been disconnected from the battery when said first load is electrically disconnected from the battery; and displaying a second message indicating that said second load has been disconnected from the battery when said second load is electrically disconnected from the battery.

56. The battery control method of claim 52 wherein providing information includes providing a message indicating that said condition of the battery is below a predetermined threshold when said ignition key signal indicates that said ignition key is in an ON position, said engine signal indicates that the engine is off, and said battery signal indicates that said condition of the battery is below said predetermined threshold.

57. The battery control method of claim 52 wherein selectively electrically connecting the plurality of loads includes progressively electrically disconnecting each of the plurality of loads when said ignition key signal indicates that said ignition key is in an ON position, said engine signal indicates that said engine is on, and said battery signal indicates that that said condition of said battery is below a predetermined threshold that corresponds specifically to each of the plurality of loads.

58. The battery control method of claim 57 wherein progressively electrically disconnecting each of the plurality of loads includes prioritizing each of the loads based on at least one of regulations, customer importance, energy consumption and power consumption.

59. The system according to claim 1 , further including: a battery for supplying electrical power in the vehicle, wherein the controller receives a battery signal representative of a condition of said battery, an ignition key signal representative of a state of an ignition key of the vehicle, and an engine signal representative of a state of an engine in the vehicle; a plurality of loads selectively electrically disconnected from said battery by said controller in response to said battery signal, said ignition key signal and said engine signal, said controller electrically disconnecting a load A1 of said plurality of loads when said ignition key signal indicates that said ignition key is not in an ON position and said battery signal indicates said condition of said battery is below a threshold A1 , and said controller electrically disconnecting a load A1 +N of said plurality of loads from said battery when said ignition key signal indicates that said ignition key is not in said ON position and said battery signal indicates that said condition of said battery is below a threshold A1+N, said threshold A1+N being lower than said threshold A1 ; and an interface providing a message A1 when said load A1 is electrically disconnected from said battery and providing a message A1 +N when said load A1+N is electrically disconnected from said battery.

60. The control system of claim 59 wherein said interface provides a message B1 when said ignition key signal indicates that said ignition key is in an ON position, said engine signal indicates that said engine is off, and said battery signal indicates that said condition of said battery is below a threshold B1.

61. The control system of claim 60 wherein said controller electrically disconnects a load C1 when said ignition key signal indicates that said ignition key is in an ON position, said engine signal indicates that said engine is on, and said battery signal indicates that that said condition of said battery is below a threshold C1 , and said controller electrically disconnects a load C1 +N when said ignition key signal indicates that said ignition key is in an ON position, said engine signal indicates that said engine is on, and said battery signal indicates that that said condition of said battery is below a threshold C1 +N.

62. The system according to claim 1 , wherein said controller controls an idle speed of the engine in response to the SOC detected by the sensor, wherein said controller is provisioned to skip at least one specific engine idle speed that has been identified as a cause of at least one of: unwanted noise in the vehicle; unwanted vibrations in the vehicle; undesirable emissions control; or undesirable driveline torque.

63. The engine idle control system of claim 62 wherein the idle speed of the engine is adjustable between a maximum engine idle speed and a minimum engine idle speed.

64. The engine idle control system of claim 63 wherein the skipped specific engine idle speed is between the maximum and minimum engine idle speeds.

65. The engine idle control system of claim 64 wherein the controller controls the idle speed of the engine so as to achieve a relatively higher engine idle speed in response to a relatively lower SOC detected by the sensor and a relatively lower engine idle speed in response to a relatively higher SOC detected by the sensor.

66. The engine idle control system of claim 65 wherein the generator generates electric power in proportion to a rotational speed at which the generator is driven by the engine.

67. The engine idle control system of claim 66 wherein the rotational speed at which the generator is driven by the engine is proportional to a rotational speed at which the engine is operated.

68. The engine idle control system of claim 67 wherein the generator is an alternating current generator.

69. The system according to claim 20, further including: means for controlling an idle speed of the engine in response to the

SOC detected by the sensing means, wherein said control means is provisioned to skip at least one specific engine idle speed that has been identified as a cause of at least one of: unwanted noise in the vehicle; unwanted vibrations in the vehicle; undesirable emissions control; or undesirable driveline torque.

70. The engine idle control system of claim 69 wherein the idle speed of the engine is adjustable between a maximum engine idle speed and a minimum engine idle speed.

71. The engine idle control system of claim 70 wherein the skipped specific engine idle speed is between the maximum and minimum engine idle speeds.

72. The engine idle control system of claim 71 wherein the control means controls the idle speed of the engine so as to achieve a relatively higher engine idle speed in response to a relatively lower SOC detected by the sensing means and a relatively lower engine idle speed in response to a relatively higher SOC detected by the sensing means.

73. The engine idle control system of claim 72 wherein the generator generates electric power in proportion to a rotational speed at which the generator is driven by the engine.

74. The engine idle control system of claim 73 wherein the rotational speed at which the generator is driven by the engine is proportional to a rotational speed at which the engine is operated.

75. The engine idle control system of claim 74 wherein the generator is an alternating current generator.

76. The method according to claim 11 , further including:

(c) identifying an engine idle speed that is a cause of at least one of: unwanted noise in the vehicle; unwanted vibrations in the vehicle; undesirable emissions control; or undesirable driveline torque; (d) adjusting the idle speed of the engine in response to the determined SOC of the battery, wherein said adjustment of the idle speed of the engine is executed such that the identified engine idle speed is avoided.

77. The method of claim 76 wherein the idle speed of the engine is adjustable between a maximum engine idle speed and a minimum engine idle speed.

78. The method of claim 77 wherein the identified engine idle speed is between the maximum and minimum engine idle speeds.

79. The method of claim 78 wherein the idle speed of the engine is adjusted so as to achieve a relatively higher engine idle speed in response to a relatively lower SOC and a relatively lower engine idle speed in response to a relatively higher SOC.

80. The method of claim 79 wherein the generator generates electric power in proportion to a rotational speed at which the generator is driven by the engine.

81. The method of claim 80 wherein the rotational speed at which the generator is driven by the engine is proportional to a rotational speed at which the engine is operated.

82. The system according to claim 1 , further including: an electrical load; a battery that selectively delivers electric current to said load; a first device that protects said load from receiving excessive current from the battery; a second device that selectively connects and disconnects the load from the battery; and a controller that controls said second device in response to a detected number of ignition cycles.

83. The battery protection system of claim 82 wherein the second device is arranged between the battery and load in series with the first device.

84. The battery protection system of claim 82 wherein the second device is one of a relay or a switch having a closed state in which the load is connected to the battery and an open state in which the load is disconnected from the battery.

85. The battery protection system of claim 82 wherein the first device is a fuse.

86. The battery protection system of claim 82 wherein the second device selectively disconnects the load from the battery without having to physically disconnect the first device.

87. The battery protection system of claim 82, said battery protection system further comprising: a counter that counts the number of detected ignition cycles.

88. The battery protection system of claim 87 wherein the controller is provisioned with a threshold and obtains the counted number of ignition cycles from the counter.

89. The battery protection system of claim 88 wherein the controller compares the obtained number of ignition cycles from the counter to the threshold and in response thereto determines whether or not to disconnect the load from the battery.

90. The battery protection system of claim 89 wherein the controller controls the second device so as to: (i) leave the load connected to the battery when the obtained number of ignition cycles from the counter has not reached the threshold; and (ii) disconnect the load from the battery when the obtained number of ignition cycles from the counter has reached the threshold.

91. The battery protection system of claim 82 wherein the controller responds to receiving a reset signal by controlling the second device so as to reconnect the load to the battery.

92. The battery protection system of claim 91 wherein receiving the reset signal disables further operation of the controller thereby leaving the second device in a state where the load remains connected to the battery regardless of the number further ignition cycles experienced.

93. The method according to claim 11 , further including: selectively starting and stopping an engine of the vehicle via an ignition system, an electrical system that includes an electrical load and a battery; selectively delivering electric current to said load via a first device that protects said load from receiving excessive current;

(c) detecting ignition cycles of the engine; (d) counting the number of detected ignition cycles; and

(e) selectively disconnecting the load from the battery in response to the counted number of ignition cycles.

94. The method of claim 93 wherein step (c) further comprises: comparing the counted number of ignition cycles to a threshold; disconnecting the load from the battery when the counted number of ignition cycles reaches the threshold; and leaving the load connected to the battery when the count number of ignition cycles has not yet reached the threshold.

95. The method of claim 94 wherein the step of disconnecting the load from the battery includes controlling a second device arranged between the load and the battery.

96. The method of claim 95 wherein the second device is arranged in series with the first device.

97. The method of claim 96 wherein the first device is a fuse and the second device is one of a relay or a switch.

98. The method of claim 97 wherein step (a) further comprises: monitoring the ignition system to detect at least one of starting and stopping of the engine by the ignition system.

99. The method of claim 97, said method further comprising: selectively generating a reset signal that results in the load being reconnected to the battery after having been previously disconnected therefrom.

100. The method of claim 99 wherein the reset signal is generated in response to an operator manipulated the vehicle's operator control in designated combination.

101. The system according to claim 20, further including: means for selectively starting and stopping an engine of the vehicle; means for selectively delivering electric current to an electrical load; means for detecting ignition cycles of the engine; means for counting the number of detected ignition cycles; and means for selectively disconnecting the load from the battery in response to the counted number of ignition cycles.

102. In a vehicle having a battery that selectively supplies electric power for starting an engine of the vehicle and that selectively supplies electric power to a plurality of electric loads of the vehicle, a method of protecting the battery comprising:

(a) obtaining a temperature;

(b) determining a state of charge (SOC) of the battery;

(c) determining a first threshold based on the obtained temperature; (d) determining a second threshold based on the obtained temperature, said second threshold being different than the first threshold;

(e) taking a first remedial action if the SOC is below the first determined threshold; and (f) taking a second remedial action if the SOC is below the second determined threshold, said second remedial action being different from the first remedial action.

103. The method of claim 102, said method further comprising: monitoring a state of an ignition switch of the vehicle, wherein said ignition switch is in either one of an ON state or an OFF state and wherein steps (c) through (f) are only executed when the ignition switch is in the OFF state.

104. The method of claim 103, wherein if the ignition switch is in the

ON state, then said method comprises: omitting steps (c) through (f); determining a third threshold based on the obtained temperature, said third threshold being different from the first and second thresholds; and taking a third remedial action if the SOC is below the third determined threshold, said third remedial action being different from the first and second remedial actions.

105. The method of claim 104, wherein step (a) comprises: measuring at least one of a temperature of the battery, a temperature of the vehicle's engine and an ambient temperature.

106. The method of claim 105, wherein the first remedial action includes electrically disconnecting a first electric load from the battery.

107. The method of claim 106, wherein the second remedial action includes electrically disconnecting a second electric load from the battery, said second electric load being different from the first electric load.

108. The method of claim 107, wherein the third remedial action includes outputting a humanly perceivable warning indication regarding the SOC of the battery.

109. The method of claim 108 wherein for the same given temperature obtained in step (a) the second determined threshold is less than the first determined threshold.

110. The method of claim 109 wherein for the same given temperature obtained in step (a) the third determine threshold is between the first and second determined thresholds.

111. In a vehicle having a battery that selectively supplies electric power for starting an engine of the vehicle and that selectively supplies electric power to a plurality of electric loads of the vehicle, a battery protection system comprising: temperature sensing means for obtaining a temperature; battery sensing means for determining a state of charge (SOC) of the battery; threshold determining means for determining a first threshold based on the temperature obtained by the temperature sensing means and a second threshold based on the temperature obtained by the temperature sensing means, said second threshold being different than the first threshold; and remedial action means for taking a first remedial action if the SOC is below the first determined threshold and a second remedial action if the SOC is below the second determined threshold, said second remedial action being different from the first remedial action.

112. The battery protection system of claim 111 , said battery protection system further comprising: monitoring means for monitoring a state of an ignition switch of the vehicle, wherein said ignition switch is in either one of an ON state or an OFF state and wherein the first and second remedial actions are only taken by the remedial action means when the ignition switch is in the OFF state.

113. The battery protection system of claim 112, wherein if the ignition switch is in the ON state, then the threshold determining means determines a third threshold based on the temperature obtained by the temperature sensing means, said third threshold being different from the first and second thresholds, and the remedial action means takes a third remedial action if the SOC is below the third determined threshold, said third remedial action being different from the first and second remedial actions.

114. The battery protection system of claim 113, wherein the temperature sensing means measures at least one of a temperature of the battery, a temperature of the vehicle's engine and an ambient temperature.

115. The battery protection system of claim 114, wherein the first remedial action includes electrically disconnecting a first electric load from the battery.

116. The battery protection system of claim 115, wherein the second remedial action includes electrically disconnecting a second electric load from the battery, said second electric load being different from the first electric load.

117. The battery protection system of claim 116, further comprising: an output device, wherein the third remedial action includes outputting on the output device a humanly perceivable warning indication regarding the SOC of the battery.

118. The battery protection system of claim 117, wherein for the same given temperature obtained by the temperature sensing means, the second determined threshold is less than the first determined threshold.

119. The battery protection system of claim 118, wherein for the same given temperature obtained by the temperature sensing means, the third determine threshold is between the first and second determined thresholds.

120. In a vehicle having a battery that selectively supplies electric power for starting an engine of the vehicle and that selectively supplies electric power to a plurality of electric loads of the vehicle, a battery protection system comprising; a first sensor that measures at least one of a temperature of the battery, a temperature of the vehicle's engine and an ambient temperature; a second sensor that detects a state of charge (SOC) of the battery; and a controller that: (i) determines a plurality of different thresholds based upon the measurement from the first sensor; (ii) compares the SOC detected by the second sensor to the plurality of thresholds; and (iii) selectively triggers a plurality or different remedial actions in response to comparing the detected SOC to the plurality of different thresholds.

121. The battery protection system of claim 120, further comprising: at least one relay arranged between the battery and at least one of the plurality of electric loads, wherein at least one remedial action includes controlling the at least one relay to selectively cut-off electric power from the battery to at least one of the plurality of electric loads.

122. In a vehicle having an electrical system including a ground circuit that provides an operative connection from the electrical system to an electrical ground and an electric power generator driven by an engine of the vehicle, said generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle, a fault detection system for detecting at least one of an open circuit or high resistance fault in the ground circuit, said fault detection system comprising: a controller that controls a voltage output of the generator so as to at least one of restrict or suspend charging of the battery or increase or start charging of the battery by the generator for a designated test period; and determining means for determining at least one of a current discharge from the battery during the test period or a charging current into the battery during the test period; wherein if the determined current discharge from the battery during the test period or the determined charging current into the battery during the test period is less than a given threshold, then at least one of an open circuit or high resistance fault is deemed to be detected in the ground circuit.

123. The fault detection system of claim 122, wherein the generator is operable in one of two modes including a HI voltage output mode and a LO voltage output mode.

124. The fault detection system of claim 123, wherein the controller provides a control signal to the generator instructing the generator to operate in the LO voltage output mode during the test period.

125. The fault detection system of claim 123, wherein an output voltage of the generator when operating in the HI voltage output mode is approximately 14.5 volts.

126. The fault detection system of claim 123, wherein the output voltage of the generator when operating in the LO voltage output mode is approximately 12.5 volts.

127. The fault detection system of claim 123, wherein the generator is a linear alternating current generator (ACG) capable of outputting an arbitrary voltage as commanded by the controller.

128. The fault detection system of claim 122, wherein the determining means includes a sensor that measures at least one of the current flowing out of the battery or the current flowing into the battery.

129. The fault detection system of claim 122, wherein the determining means indirectly measures the battery current by sensing the output current from the generator and the current to vehicle's electrical load.

130. The fault detection system of claim 122, wherein the determining means estimates the battery current based upon operating data characterizing operation of the generator and knowledge of an operational status of the vehicle's electrical load.

131. The fault detection system of claim 128, wherein the ground circuit includes an electrical conductor operatively connecting a negative terminal of the battery through the sensor to the electrical ground.

132. In a vehicle having an electrical system including a ground circuit that provides an operative connection from the electrical system to an electrical ground and an electric power generator driven by an engine of the vehicle, said generator arranged to selectively provide electric power to an electrical load of the vehicle and to selectively charge a battery of the vehicle, a method for detecting at least one of an open circuit fault or a high resistance fault in the ground circuit, said method comprising:

(a) controlling a voltage output of the generator so as to at least one of restrict or suspend charging or increase or start charging of the battery by the generator for a designated test period; and

(b) determining at least one of a current discharge from the battery during the test period or a charging current into the battery during the test period, wherein if the determined current discharge or charging current is less than a given threshold, then at least one of an open circuit or high resistance fault is deemed to be detected in the ground circuit.

133. The method of claim 132, wherein the generator is operable in one of two modes including a HI voltage output mode and a LO voltage output mode.

134. The method of claim 133, wherein step (a) includes providing a control signal to the generator instructing the generator to operate in the LO voltage output mode during the test period.

135. The method of claim 133, wherein an output voltage of the generator when operating in the HI voltage output mode is approximately 14.5 volts.

136. The method of claim 133, wherein the output voltage of the generator when operating in the LO voltage output mode is approximately 12.5 volts.

137. The method of claim 133, wherein the generator is a linear alternating current generator (ACG) capable of outputting an arbitrary voltage as commanded by the controller.

138. The method of claim 132, wherein step (b) includes directly measuring at least one of the discharge current from the battery or the charging current into the battery.

139. The method of claim 132, wherein step (b) includes indirectly measuring the battery current by sensing the output current from the generator and the current to vehicle's electrical load.

140. The method of claim 132, wherein step (b) includes estimating the battery current based upon operating data characterizing operation of the generator and knowledge of an operational status of the vehicle's electrical load.

141. The method of claim 132, wherein the ground circuit includes an electrical conductor operatively connecting a negative terminal of the battery to the electrical ground.