MXPA01004005A - Battery pack having a state of charge indicator - Google Patents

Abstract

A battery pack (10) for a portable electronic device includes a case (12) for carrying a battery (36). The case (12) supports a charge sensing circuit (20) carried by the case, the charge sensing circuit producing a discharge signal corresponding to a measurement of an amount of charge removed from a battery. The case also supports a processor (22) responsive to the discharge signal from the charge sensor circuit to produce a signal corresponding to an amount of time prior to discharge of the battery based on a current rate of discharge and a display (14) responsive to the signal to display a time period corresponding to the amount of time to discharge the battery based upon the current rate of discharge of the battery.

Description

BATTERY PACKING THAT HAS A STATE INDICATOR OF LOAD DESCRIPTION OF THE INVENTION This invention relates to batteries for portable devices such as computers, video cameras and cell phones. The batteries are used to power portable electronic equipment. Frequently batteries are used with equipment that gives an indication of a quantity of charge left in the battery. The charge indicator visually shows an indication of a percentage of remaining useful energy, compared to that of the fully charged battery. Sometimes these indicators are carried by the battery cell and are often of the chemical type. Sometimes indicators are produced by circuits contained in the electronic device such as cell phone or the like. When the indicator is produced by the device, the indicator is often a screen such as a LCD screen of a battery, divided into segments. Each segment is turned on or enabled to represent a percentage of energy left in the battery. As the energy is drained from the battery, the Ref: 128986 segments with the remnants that indicate the remaining energy in the battery. According to one aspect of the invention, a package or battery pack for a portable electronic device includes a carrying case for carrying a battery. The case supports a charge sensing circuit carried by the case, the charge detecting circuit produces a discharge signal corresponding to a measurement of a quantity of charge removed from a battery. The case also supports a processor that responds to the discharge signal from the load sensing circuit to produce a signal corresponding to an amount of time before the battery is discharged, based on a rate or proportion of discharge current and a screen that responds to the signal to visually display a period of time corresponding to the amount of time to discharge the battery, based on the current speed of battery discharge. The battery pack may include a charge sensing circuit that measures the amount of charge removed from the battery. The sensing circuit can be a Coulombic counting circuit that counts a number of charge units removed from the battery. The screen can be a liquid crystal display, electrophoretic, or electronic ink screen. The battery pack can carry at least one battery cell inside the case. The processor responds to a load signal and produces the corresponding signal for a quantity of time before discharge, based on the load signal and a discharge signal from the load sensing circuit. The processor produces a signal corresponding to a message indicating a mode of operation of the battery and the message is visually displayed on the screen. The message may correspond to an operation mode or a diagnostic mode. According to another aspect of the invention, a battery pack for a portable electronic device includes a case carrying a battery, the case supporting a charge sensing circuit to produce an electrical signal corresponding to a measurement of a quantity of charge removed from the battery. the battery, and a processor that responds to the electrical signal from the load sensing circuit to produce a signal corresponding to a quantity of time before the battery discharge according to a battery operation history. The battery pack also includes a screen that responds to the signal indicating the amount of time before the discharge, to visually display a period of time corresponding to the amount of time to discharge the battery, based on a current mode, of battery operation. According to a further aspect of the invention, a method indicating the remaining time to discharge a battery, includes the measurement and accumulation of a quantity of charge removed from the battery, the determination of the remaining time to discharge the battery from the amount of accumulated charge removed from the battery, and from a current, operating mode of the battery, and that visually shows a period of time corresponding to the amount of time to discharge the battery. According to a further aspect of the invention, a method of indicating the remaining time to charge a battery contained in a battery case includes measuring and accumulating a quantity of charge inserted in the battery during battery charging, and determination of the remaining time to charge the battery from the amount of accumulated charge inserted in the battery. The method also includes the visual representation, on a screen carried by the battery case, of a period of time corresponding to the amount of time to charge the battery.

One or more of the following advantages are provided by the invention. The screen may have fields to visually display various messages of the type of status or condition. The processor may cause the charge measurements to be removed from a rechargeable battery cell or be added to a rechargeable battery cell. These measurements are used to determine the amount of time that the cells in the battery have to discharge and charge. The time is calculated according to the maximum capacity of the cells of the battery, and either the charging speed or the discharge speed of the cells of the battery, according to the mode of use, for example, the mode of conversation or waiting. This simplifies a user's estimate of the battery's ability to last for a particular use before reaching the discharge. In addition, because the screen is in the battery, its time to download can be evaluated by a user without having to attach the battery to a device such as a video camera or cell phone. Figure 1 is a perspective view of a battery pack carrying a screen. Figure 2 is a block diagram of a microprocessor-based controller for calculating a time-based charge state for the cells in the battery pack of Figure 1. Figure 3 is a flow chart showing a process for the determination of a state of charge. Figure 4 is a flow chart showing a process for determining an operational mode of a battery. Figure 5 is a flow diagram showing a process for calculating capacity. Referring now to Figure 1, a battery pack 10 includes a case 12 having a display 14. Case 12 houses rechargeable battery cells, a controller (as will be described in conjunction with Figure 2) and an electrical terminal 16 for connection to a user's device such as a cell phone, video recorder, etc. The case 12 can be configured to fit the user's apparatus. The case 12 carries the display 14. The display 14 includes a numeric message field indicating, in general, in hours and minutes, the amount of time remaining to charge the battery, or to discharge the battery, in accordance with the mode of operation of the battery. That is, the screen will show a first time for discharge when the battery is in a usage mode, and a second time remaining for the discharge when it is in standby mode. This first and second times are determined according to the capacity of the battery and the draining of the charge from the battery, depending on the mode. Alternatively, the screen can visually display the time to charge the battery during charging operations. Screen 14 may have fields to visually display the various messages of the condition or status type. In particular, the screen 14 may have a field indicating the current mode of operation of the battery. For example, the message "CONVERSATION" 14c can be displayed on a battery used in cell phones, and indicates that the battery is connected to a telephone currently in use, while the message "WAITING", for example, the wait 14e, can be displayed when the battery is in a standby operation mode. In addition, the battery can display messages such as "COMPLETE LOAD REQUIRED" 14f, ^ REPLACE SOON ", 14g and" INT EXT "14a that can be used to indicate whether an internal or external charger is being used.The screen 14 can visually display the time "FOR COMPLETE LOAD", and so on. Referring now to Figure 2, a microprocessor-based controller 20 is shown to generate signals, to cause the appropriate messages to be displayed visually on the screen 14. The controller 20 based in microprocessor includes a processor 22 powered via a memory 24 having a computer program 40 in the form of computer hardware (software), or microprogram stored therein, which controls the operation of the processor 22 and allows the processor 22 to cause the energy measurements to be removed from a rechargeable battery cell or to be added to a rechargeable battery cell 36. These measurements are used to evaluate the amount of time that the battery cells have to discharge and charge according to the maximum capacity of battery cells, and either the charging speed, or the discharge speed of the battery cells of the battery cells. according to the mode or use, for example, the conversation or waiting mode. Optionally, the leakage of the charge coming from the battery can also be calculated. The leakage of the load may be based on known or estimated leak rates. The processor controls an A / D converter 26 which provides the data corresponding to the measurements made of the state of the cells 36 of the battery. The A / D converter 26 detects the current fed to the battery cells by means of a charger 30, and also detects the current drawn from the cells of the rechargeable battery, via an energy monitor circuit 28. The energy monitoring or monitoring circuit can operate using various known modes. A preferred mode is the so-called "Coulombical counting mode" in which the charge that is removed from the battery is determined. Under the control of the program 40, the A / D converter will sample these signals and feed these signals to the processor 22 to allow the processor to make the necessary measurements of these parameters. Optionally, the controller 20 as well as the charge can be realized via a solar panel 32. Alternatively, the rechargeable battery cells 36 can supply current to the electronic circuits 20 of the controller. Referring now to Figure 3, a program 40 is shown to provide a time state of the load display format for the display 14. The program 40 includes an initialization routine 42 which initializes various components in the controller 20, such as be necessary. The controller 20 will enter a sleep mode 24 and remain in that mode unless awakened by a stopwatch signal 43 or some other event. For example, the program 40 can exit the sleep mode via an interruption of the circuit of periodic verification of the energy or of the chronometers of the computer hardware (software) or of the physical equipment (hardware). After exiting sleep mode, the program causes the processor to read 46 analog-to-digital converter outputs (26, Figure 2). The A / D converter (26, Figure 2) will be powered via the discharge current from the rechargeable battery cells 36 via the periodic power verification circuit 28, as well as a charging current from the charger 30, depending on the use of the battery. The processor will determine the operation mode 48 of the battery and will call an average current routine that will calculate the average current that is drawn from the battery in a period of time. Details on a procedure for determining the mode of operation are described in Figure 4. The processor will calculate the remaining battery capacity (using a routine (Figure 5, or equivalent)) and determine the end of the load and the end of the load. Battery discharge states 36. The processor will calculate the remaining time to charge or discharge the battery according to the battery operation mode, and will produce signals that are used by a screen control routine to make the various possible messages 14a-14g on the screen 14. After this, the processor resets the operation and returns to a sleep mode 34 waiting for the next event.

Referring now to Figure 4, the process 48 for determining the mode of operation of the battery 10 includes determining 60 a direction of current flow from the battery. The direction of the current flow determines whether the battery is in the use or standby state, or in a state of charge. If the direction of the current flow is negative, for example, the battery is being discharged, the process will determine whether the current drawn from the battery exceeds a predetermined threshold for a specific period of time. Frequently the batteries used in cell phones or camcorders have maximum holding currents that may exceed the minimum usage currents. Therefore, in order to provide accurate representations of the amount of time available in each mode, it is necessary to filter the current consumption and add current consumption to the appropriate mode. Therefore, the process 48 determines 62 the amount of current drawn from the battery in a specific period of time. This assumes that the peak currents are exceeded for a specific period of time in a "use" mode; since those peak currents are not exceeded in a prolonged period of time during the standby mode. If the process determines 62 that the current does not exceed any threshold for a specified period of time, that indicates that the battery is in a "use" mode such as a "conversation" mode for a cell phone. Therefore, the current consumed in the "use" mode for example, conversation, is added to the previous usage currents and the time spent in that way is also increased. If the threshold was not exceeded for the specified period of time, the battery is in a standby mode and the standby currents are added 68, and the time in that mode is increased. If the current flow direction was inside the battery or if there was no current flow, those occurrences indicate that the battery is in an "off" state or in a "charge" state. In the off state, the battery can still have a small negative current flow and such currents and corresponding times are added 74. The current in the use or conversation mode, the standby current and the currents in the off state are added 70 to provide a total current that is used to calculate an average current 72. The mode detection process 48 calculates an average current by dividing the total current by the total time in which the battery has been operated. The mode detection process 48 then calls a retention time calculation process 80. The remaining time process 80 determines the amount of time left to fully discharge the battery or charge the battery, depending on the mode of operation, as determined in Figure 4. Various models of remaining time can be used. A model is a floating average technique in which a moving average of current consumption is calculated separately for the current when the battery is in a "use" mode or in a "standby" mode. A disadvantage with this method is that since the process is a moving average, the amount of time to discharge can in fact be increased when an average current value decreases relatively quickly. To cushion this effect, a non-floating average can be used, in which the average current is updated in very long time intervals with values actually learned. This model provides a smoother output because the amount of current used in the calculations is constant during a calculation cycle. An alternative model is a time account model. In the time account model, a time account record is decremented to count down the amount of time remaining in the time account record. This technique provides an accurate account of the time the battery spends in the various modes. With reference now to Figure 5, the time count model mode of the remaining time calculation 80 calculates 82 the remaining time to discharge the battery once per charge cycle, and initializes 84 a pair of "remaining time records for discharge" (not shown) with the time value corresponding to the amount of time necessary to discharge the battery according to each mode such as "USE" for example, conversation and "STB" for example, wait, as in Equations 1 and 2.

REMT, USE = CAP / Iavg, USE Equation 1 REMT, STB = CAP / Iavg, STB Equation 2 The remaining time is calculated 86 by dividing the capacity of the battery by the average current consumed per period of time. The time records in the use and standby mode contain the remaining time to discharge the battery according to the mode. As a mode is determined 86, each mode record is decreased. In this way for the standby mode, the standby register mode is decreased as in Equation 3, and the usage mode record is decreased as in Equation 4.

RemT, STB = RemT, USE - 1 / min Equation 3 RemT, TLK = RemT, TLK-Iavg, STB / wash, USE / min Equation 4 If the detected mode 86 is the mode of use, the process decreases the waiting register, as in Equation 5 and decreases the usage record by an amount of time, as given by Equation 6.

RemT, STB = RemT, STB-Iavg, USE / Iave, STB / min Equation 5 RemT, USE = RemT, USE - 1 / min Equation 6 It should be understood that while the invention has been described in conjunction with the detailed description thereof, it is intended that the foregoing description should illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages and modifications are within the scope of the following claims.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (19)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A battery pack for a portable electronic device, characterized in that it comprises: a carrying case for a battery, the case supports: a load sensing circuit carried by the case, the load sensing circuit produces a discharge signal corresponding to a measurement of a quantity of charge removed from a battery; a processor that responds to the discharge signal from the load sensing circuit, to produce a signal corresponding to a quantity of time before the battery discharge, based on a current discharge rate; and a screen that responds to the signal to visually display a period of time corresponding to the amount of time to discharge the battery, based on the current battery discharge rate.

2. The battery pack according to claim 1, characterized in that the sensor circuit is a load sensing circuit that measures the amount of charge removed from the battery.

3. The battery pack according to claim 1, characterized in that the sensor circuit is a Coulombic counting circuit that counts a number of charge units removed from the battery.

4. The battery pack according to claim 1, characterized in that the screen is a low energy screen.

The battery pack according to claim 1, characterized in that the screen is a liquid crystal screen, an electrophoretic screen or an electronic ink screen.

6. The battery pack according to claim 1, characterized in that it further comprises at least one battery cell carried within the case.

The battery pack according to claim 1, characterized in that the charging sensor circuit produces a charging signal corresponding to the amount of charge fed to a battery during a charging operation mode.

The battery pack according to claim 7, characterized in that the processor responds to the load signal and produces the corresponding signal for a quantity of time before unloading, based on the load signal and the discharge signal coming from of the load sensing circuit.

9. The battery pack according to claim 1, characterized in that the processor produces a signal corresponding to a message indicating a battery operation number; and wherein the message is visually displayed by the display device.

10. The battery pack according to claim 9, characterized in that the message corresponds to an operation mode and a diagrammatic mode.

The battery pack according to claim 1, characterized in that the battery pack further comprises a battery and the charging sensor circuit, and the processor derives a power signal from the cell in the battery.

12. A battery pack for a portable electronic device, characterized in that it comprises: a case carrying a battery, the case supports: a charge sensor circuit to produce an electrical signal corresponding to a measurement of a quantity of charge removed from the battery; a processor that responds to the electrical signal coming from the load sensing circuit to produce a signal corresponding to an amount of time before the battery is discharged, according to a history of operation of the battery; and a screen that responds to the signal indicating the amount of time before the discharge, to visually display a period of time corresponding to the amount of time to discharge the battery based on a current mode of battery operation.

13. The battery pack according to claim 12, characterized in that the sensor circuit is a charge sensing circuit that measures the amount of charge removed from the battery.

14. The battery pack according to claim 12, characterized in that the sensor circuit is a Coulombic counting circuit that counts the amount of charge removed from the battery.

15. The battery pack according to claim 11, characterized in that the screen is a liquid crystal display or a light emitting diode screen, or an electrophoretic screen, or an electronic ink screen.

16. A method for indicating the time remaining to discharge a battery contained in a battery case, the method is characterized in that it comprises: the measurement and accumulation of a quantity of charge removed from the battery; determining the remaining time to discharge the battery from the amount of accumulated charge removed from the battery; and the visual representation, on a screen carried by the battery case, of a period of time corresponding to the amount of time to discharge the battery.

17. The method according to claim 15, characterized in that the time displayed visually is based on a current mode of operation of the battery.

18. A method to indicate the remaining time to charge a battery contained in a battery case, the method is characterized in that it comprises: the measurement and accumulation of a quantity of charge inserted in the battery during the charging of the battery; the determination of the remaining time to charge the battery, starting from the amount of accumulated charge inserted inside the battery; and the visual representation on a screen carried by the battery case, of a period corresponding to the amount of time to charge the battery.

19. The method according to claim 15, characterized in that the time displayed visually is based on a current mode of operation of the battery. BATTERY PACKING THAT HAS A STATE INDICATOR OF LOAD SUMMARY OF THE INVENTION A battery pack (10) for a portable electronic device including a case (12) for carrying a battery (36) is described. The case (12) supports a charge sensor circuit (20) carried by the case, the charge sensor circuit produces a discharge signal corresponding to a measurement of a quantity of charge removed from a battery. The case also supports a processor (22) that responds to the discharge signal from the charge sensing circuit, to produce a signal corresponding to a quantity of time before the battery discharge, based on a current discharge rate, and a screen (14) that responds to the signal to visually display a period of time corresponding to the amount of time to discharge the battery, based on the current speed of battery discharge.