JP4702251B2 - Battery state determination device and lead battery for automobile - Google Patents

Description

  The present invention relates to a battery state determination device and a lead battery for an automobile, and more particularly to a battery state determination device for determining a health state of a lead battery and an automotive lead battery including the battery state determination device.

  In general, a lead battery for starting an internal combustion engine is mounted on an automobile, and such a lead battery is called a lead battery for an automobile or a vehicle. The lead battery for automobiles is an extremely important component from the viewpoint of ensuring the start of the automobile. Therefore, detecting the battery state of a lead battery for an automobile is useful in the sense of, for example, predicting or guaranteeing a restart (idle stop / start, ISS) of an internal combustion engine after the automobile has stopped.

  For this reason, conventionally, attempts have been made to detect the battery state by measuring the open circuit voltage of an automotive lead battery, measuring the internal resistance using an alternating current, and measuring the charge current, discharge current and discharge voltage together. . As a specific example, there is disclosed a remaining capacity detecting device that prepares a relationship between the voltage and current of a lead battery in advance and detects the remaining capacity of the lead battery in comparison with data obtained by actual measurement. (For example, refer to Patent Document 1). In addition, when an alternating current is applied and the internal resistance exceeds a certain value, a correlation equation between the internal resistance and the remaining capacity is obtained, and based on this, the remaining capacity of the lead battery is monitored and the lifetime is estimated. A technique is disclosed (for example, see Patent Document 2). Furthermore, a technology for obtaining the internal resistance of a lead battery from an open circuit voltage and a discharge voltage without using a current sensor and detecting the health condition of the lead battery from a predetermined relationship between the internal resistance and SOH is disclosed. (For example, see Patent Document 3). In these battery state detection devices, in general, it is determined whether or not the battery has deteriorated to the extent that it is necessary to replace the lead battery, using a determination threshold value that is a criterion for deterioration determination.

JP-A-7-63830 JP 2002-334725 A JP-A-2005-304173

  However, even in the same SOH lead battery, the subsequent transition of SOH varies greatly depending on the elapsed period from the start of use of the lead battery. Lead batteries that have been used for a considerable amount of time have rapidly deteriorated compared to lead batteries of the same SOH, which have a short use period, and the engine cannot be started at a certain point. In the conventional battery state determination device, the determination threshold value used when determining the deterioration of the lead battery is set to a constant value. It is difficult to notify that the lead battery needs to be replaced. That is, there is no problem when the user or the person in charge at the vehicle inspection site intentionally inspects (determines) the health condition of the lead battery for automobiles with an inspection device such as a tester, but the battery state determination device is generally a lead battery. Because it is placed in one piece or in the vicinity of the lead battery, and in many cases it is placed in a place where the user cannot see, such as the engine room, even if the battery state determination device issues a notification that replacement is required, the user may overlook it. is there. For this reason, in order to ensure ISS etc., when a lead battery deteriorates so that replacement | exchange needs, it is desirable to issue a warning early.

  In view of the above circumstances, the present invention has an object to provide a battery state determination device capable of determining the health state of a lead battery early and appropriately without using a current sensor, and an automotive lead battery including the battery state determination device. To do.

  In order to solve the above-mentioned problem, a first aspect of the present invention is a battery state determination device for determining the health state of a lead battery, wherein the voltage measurement means for measuring the voltage of the lead battery and the voltage measurement means Calculating means for calculating a minimum voltage value at the time of discharging the lead battery, and a minimum voltage value calculated in the non-deteriorating state of the lead battery by the calculating means and a non-deteriorating or deteriorating state of the lead battery. And a state determination unit that determines the health state of the lead battery from the latest minimum voltage value calculated in Step 1, wherein the state determination unit is for deterioration determination that changes with time from the start of use of the lead battery. The health condition of the lead battery is determined using the determination threshold value.

  In this aspect, the voltage of the lead battery is measured by the voltage measuring means, and the lowest voltage value at the time of discharging of the lead battery is calculated among the voltages measured by the voltage measuring means by the calculating means. Then, the determination threshold for deterioration determination is calculated from the minimum voltage value calculated by the state determination means in the non-deterioration state of the lead battery and the latest minimum voltage value calculated in the non-deterioration or deterioration state of the lead battery. The health status of the lead battery is determined using the value, but the status determination means determines the health status of the lead battery using a determination threshold value for deterioration determination that changes with the time since the start of use of the lead battery. To do. According to this aspect, since the state determination unit determines the health state of the lead battery from the lowest voltage value calculated by the calculation unit in the non-degraded state of the lead battery and the latest lowest voltage value, the current sensor is used. In addition to being able to determine the health condition of the lead battery, the condition determination means uses a determination threshold value that changes depending on the time since the start of use of the lead battery. It can be determined early and appropriately.

  In this aspect, the lead battery is a lead battery for automobiles, and the minimum voltage value calculated by the calculating means is preferably the minimum voltage value among the discharge-time voltages of the lead battery when driving the cell motor for starting the engine. . In addition, a time measuring means for measuring time is provided, and the state determining means determines the relationship between the time from the start of use of the lead battery and the determination threshold value from the time from the start of use of the lead battery measured by the time measuring means. The determination threshold value may be calculated using a map or a mathematical expression. At this time, if the nonvolatile memory is further provided and the time measuring means stores the time from the start of use of the lead battery every time a certain time elapses, the power supply to the battery state detection device is interrupted. Even after that (when power is resupplied), the time from the start of use of the lead battery stored in the memory can be read to determine the health condition of the lead battery.

  Moreover, in order to solve the said subject, the 2nd aspect of this invention is a lead battery provided with the battery state determination apparatus of the 1st aspect. The lead battery of the second aspect also has the same operational effects as the first aspect.

  According to the present invention, since the state determination means determines the health state of the lead battery from the lowest voltage value calculated by the calculation means in the non-degraded state of the lead battery and the latest lowest voltage value, the current sensor is used. In addition to being able to determine the health condition of the lead battery, the condition determination means uses a determination threshold value that changes depending on the time since the start of use of the lead battery. The effect that it can determine early and appropriately can be acquired.

  Hereinafter, an embodiment in which the present invention is applied to an automotive lead battery (model: 65B24R) will be described with reference to the drawings.

(Constitution)
As shown in FIG. 1, the lead battery 10 of the present embodiment has a substantially rectangular battery case 8 serving as a battery container, and a total of six electrode plate groups are accommodated in the battery case 8. Yes. For the material of the battery case 8, it is possible to select a polymer resin such as polyethylene (PE), polypropylene (PP), and acrylic butadiene styrene (ABS) that is excellent in terms of moldability, insulation, and durability. it can. In each electrode plate group, a plurality of negative electrodes and positive electrodes are laminated via a separator, and the cell voltage is set to 2.0V. Therefore, the nominal voltage of the lead battery 10 is 12V. The upper part of the battery case 8 is bonded or welded to an upper lid 9 made of a polymer resin such as PE that seals the upper opening of the battery case 8.

  The upper lid 9 is provided with two (positive and negative) output terminals 7 for supplying electric power to the outside by using the lead battery 10 as an automobile power source. In addition, the upper lid 9 houses (incorporates) an AI unit 1 as a battery state determination device that determines the health state of the lead battery 10.

  The AI unit 1 is composed of an AD converter, a reference power source, etc., and measures a voltage of the lead battery 10, a temperature measuring unit, which is composed of an AD converter, a thermistor, etc., and measures the temperature of the lead battery 10, and a microprocessor , ROM, RAM, nonvolatile memory EEPROM, etc., a coil-type buzzer (not shown), a transistor for operating the buzzer, resistors, etc. A notification unit to be generated, an operation display unit configured to include an operation button 3, a light emitting diode (hereinafter referred to as an LED), a transistor, a resistor, and the like, and turn on the LED to indicate that the lead battery 10 needs to be replaced. 2 are provided. The AI unit 1 is connected to the output terminal 7 by a connecting conductor in the upper lid 9, and operating power is supplied from the lead battery 10.

  A buzzer sound emitting hole 6 is formed at a position where the buzzer of the AI unit 1 is mounted on the upper lid 9, and the upper surface of the operation display unit 2 of the AI unit 1 is substantially flush with the upper surface of the upper lid 9. .

(Degradation judgment principle)
Next, the principle of determining deterioration (health state) of the lead battery 10 by the AI unit 1 will be described.

  The microprocessor (hereinafter abbreviated as MP) captures the digital voltage value of the lead battery 10 via the voltage measurement unit and stores it in the RAM every predetermined time (for example, 2 ms). The health condition of the lead battery 10 is determined based on the above.

  In general, in an automobile having an internal combustion engine such as a gasoline engine vehicle or a diesel engine vehicle, electric power is supplied from a lead battery, and a cell motor is rotated to start the engine. At this time, a large current flows, and accordingly, the voltage between the terminals of the lead battery greatly drops. When measuring the voltage drop and the time change of the current at this time, immediately after the current started to flow to the cell motor, a sharp peak-shaped large current flowed. As shown in FIG. 3 and FIG. The voltage shows a sharp valley-like voltage drop. The minimum voltage value Vst at which this voltage drop is maximum appears simultaneously at the maximum current value Ist at which the discharge current from the lead battery is maximum.

  Assuming that the engine starting system electrical resistance is R, Ohm's law is established as shown in the following formula (1) at the timing when the minimum voltage value Vst and the maximum current value Ist appear.

  The engine starting system electric resistance R is the resistance of the engine starting system constituted by a cell motor, a harness, etc. at the time of starting the engine. The total resistance obtained by adding the resistance of the cell motor as a stationary conductor to the resistance of the vehicle harness, electric contact, etc. It is. It should be noted that the engine starting system electric resistance R is a constant value only at the timing when the minimum voltage value Vst is taken, and at other timings, the engine starting system electric resistance R changes with time. Not satisfied.

  In other words, if the vehicle is the same, if the engine starting voltage can be acquired at the timing of the lowest voltage value Vst, the engine starting system electric resistance R itself is a constant with a constant resistance value using the formula (1). This resistor can be used to judge deterioration of lead batteries.

  On the other hand, when the open circuit voltage of the lead battery is Vo and the internal resistance of the lead battery is r at the timing when the minimum voltage value Vst and the maximum current value Ist appear, the following equation (2) is established.

  By substituting equation (1) into equation (2), the following equation (3) is obtained.

  From equation (3), it can be seen that the minimum voltage value Vst is a function of the open circuit voltage Vo, the engine starting system electrical resistance R, and the internal resistance r of the lead battery. The internal resistance r shows the minimum value in the non-degraded state of the lead battery, and increases as the health state (SOH) decreases. Therefore, from Equation (3), the minimum voltage value Vst is an indicator of the health status of the lead battery. In other words, when the health state of the lead battery is reduced (when the lead battery is deteriorated), the internal resistance r is increased, so that the minimum voltage value Vst is lowered.

  FIG. 5 shows the transition of the terminal voltage of the lead battery at the time of starting the engine for the lead battery in the non-degraded state (initial state) and the same lead battery after deterioration. In FIG. 5, the lowest voltage value at the time of starting the engine of the lead battery in the non-degraded state is represented by Vst0, and the lowest voltage value at the time of starting the engine after deterioration is represented by Vst. In FIG. 5, as the lead battery deteriorates, the voltage difference ΔVst (= Vst0−Vst) between the lowest voltage value Vst0 in the non-degraded state and the lowest voltage value Vst after deterioration increases.

  In accordance with the above principle, the AI unit 1 determines that the lead battery 10 has deteriorated and needs to be replaced when the voltage difference ΔVst becomes larger than a determination threshold value Vth described later. However, as described above, in order to use the above principle (Equation (1)), it is assumed that the minimum voltage values Vst0 and Vst at the time of starting the engine are accurately obtained. Therefore, the minimum voltage values Vst0 and Vst Need to be acquired at the optimal timing.

(Engine condition judgment)
The AI unit 1 also has a function of detecting the engine state based on the voltage of the lead battery 10 measured through the voltage measuring unit. That is, the MP constantly monitors (measures) the voltage of the lead battery 10, and determines the engine state of engine start, engine start, and engine stop from the change in voltage measured via the voltage measurement unit.

<Engine start>
MP is a voltage drop of Y (0.50 to 3.0) V or more within X (1 to 100) ms after the start of discharge of the lead battery 10 (for example, preferably a voltage drop of 1.5 V or more within 15 ms). It is determined whether or not the engine has started and the engine has been started when the determination is affirmative. For example, a voltage value of 109 to 121% of the OCV of the lead battery 10 can be used as the voltage value of a. On the other hand, when a negative determination is made, it is considered that an in-vehicle electrical component such as a car air conditioner or a car navigation system has been started, and the engine is not started.

<Engine is running>
MP is a lead battery, because the voltage of the lead battery 10 is always greater than or equal to the above-described predetermined value a after the affirmative determination of the engine start described above (the generator (alternator, regulator) is operating when the engine is running). 10 is in a charged state, and the voltage is higher than OCV.) When the determination is affirmative, it is determined that the engine is being started.

<Engine stop>
(1) After determining that the engine is being started, if the voltage of the lead battery 10 becomes equal to or less than a certain value b: it is determined that the engine is stopped from the engine starting state. For example, a voltage value of 103 to 108% of the OCV of the lead battery 10 can be used as the voltage value of b. Also, (2) after determining that the engine is being started, when the voltage of the lead battery 10 decreases at a speed equal to or higher than a certain value c and the voltage drop is equal to or more than a certain value d: It is determined that the vehicle has stopped. The voltage drop rate of c can be 1.0 to 4.0 V / s, and the voltage drop width of d can be 0.05 to 0.20 V. Further, (3) after determining that the engine is in operation, the voltage of the lead battery 10 decreases to a certain value e or less, and the voltage change width at that time is a certain constant value f with a certain time width. When the value is less than or equal to g: It is determined that the engine is stopped from the engine starting state. A voltage value of 102 to 109% of the OCV of the lead battery 10 can be used as the voltage value of e, 0.01 to 1.0 s can be used as the value of f, and 0.1 to 0.3 V can be used as the change width of the voltage of g. . MP determines that the engine has stopped when it falls under any of (1) to (3).

  In addition, MP acquires the voltage of the lead battery 10 measured after the polarization reaction of the lead battery 10 is eliminated after the engine is stopped (for example, after 6 hours have elapsed) as an OCV.

(Operation)
Next, with reference to a flowchart, the operation of the AI unit 1 will be described with the MP as a main component. When power is supplied from the lead battery 1 to the AI unit 1, program data including a program and a determination threshold value Vth is expanded from the ROM to the RAM in the initial setting process to determine deterioration of the lead battery 10. The deterioration determination routine is executed.

  As shown in FIG. 2, in the deterioration determination routine, first, in step 102, the process waits until the engine is started. The MP determines the engine start based on the engine state determination described above. When it is determined that the engine has been started, in the next step 104, referring to the voltage value stored in the RAM, the first lowest voltage value measured at the start of discharge of the lead battery 10 and after the start of discharge of the lead battery 10 The lowest voltage value measured within 15 ms is calculated as the lowest voltage value Vst at engine start. Note that the MP measures the temperature of the lead battery 10 via the temperature measuring unit, and corrects the temperature of the lowest voltage value Vst to, for example, a voltage value at room temperature (25 ° C.) based on the acquired temperature value.

  In the next step 106, it is determined with reference to the EEPROM whether or not the lowest voltage value Vst0 at the time of starting the engine of the lead battery 10 in the non-deteriorated state has already been acquired. That is, if the minimum voltage value Vst0 is written at a predetermined address in the EEPROM, it is determined that the minimum voltage value Vst0 has already been acquired (affirmed). If it is null, the minimum voltage value Vst0 is acquired. Judge that it is not (deny).

  If the determination in step 106 is negative, it is determined in step 108 whether or not the minimum voltage value Vst calculated in step 104 satisfies the condition of the minimum voltage value Vst0 when the engine of the lead battery 10 in the non-degraded state is started. to decide. This condition is, for example, (1) within six months from when the lead battery 10 is attached to the automobile (beginning of use), and (2) the OCV of the lead battery 10 before starting the engine (for example, The open circuit voltage when 6 hours have elapsed since the previous engine stop) can be 12.5 V or more. In the present embodiment, since the operation button 3 is arranged on the operation display unit 2, in order to determine the condition (1), for example, when the operation button 3 is pressed a predetermined number of times by a predetermined operation, the MP is Alternatively, it may be determined that the lead battery 10 is attached to the automobile and time is measured from that time. As is clear from condition (1), “no degradation state” of “minimum voltage value Vst0 at start of engine of lead battery 10 in no degradation state” in this embodiment is a complete SOH of 100%. Not only the non-degraded state but also the substantially non-degraded state in the initial state in which the lead battery 10 is healthy.

  When a negative determination is made at step 108, the process returns to step 102 in order to obtain the lowest voltage value Vst0 at the time of engine start of the non-deteriorated lead battery 10, and when an affirmative determination is made, the calculation is made at step 104 at step 110. The lowest voltage value Vst is stored (written) in the EEPROM as the lowest voltage value Vst0 when the engine of the lead battery 10 in the non-degraded state is started, and the routine proceeds to step 112.

  On the other hand, if the determination in step 106 is affirmative, in step 112, the minimum voltage value Vst0 at the time of engine start of the non-degraded lead battery 10 is read from the EEPROM. ) Is calculated.

  In the next step 116, a determination threshold value Vth which is one of the features of the present invention is calculated. That is, the MP measures the time from when the lead battery 10 is attached to the vehicle (beginning of use) by an internal clock, and the use of the lead battery 10 is started as shown by the solid line in FIG. The determination threshold value Vth at the present time is calculated using a relational expression that defines the relationship between the time from and the determination threshold value. In FIG. 6, for reference, an example in which the conventional determination threshold value is a fixed value is indicated by a broken line. In general, it is said that the replacement time of the lead battery for automobiles is about three years from the start of use. In this embodiment, the judgment threshold value is larger than the fixed value before the lapse of this time, and the fixed value is obtained after the lapse. It becomes smaller than the case of.

  Next, in step 116, it is determined whether or not the voltage difference ΔVst is larger than the determination threshold value Vth. When the determination is negative, since the deterioration has not progressed to the extent that the lead battery 10 needs to be replaced, it is not necessary to issue a warning to the user (driver), and the process returns to step 102.

  On the other hand, when the determination in step 116 is affirmative, in the next step 118, the process waits until the engine stops. The MP determines the engine stop by the above-described engine state determination. When it is determined that the engine is stopped, in the next step 120, as described below, the fact that the lead battery 10 needs to be replaced is notified by an audible means using a buzzer and a visual means using an LED, and the process returns to step 102. .

  In the present embodiment, since the AI unit 1 is accommodated in the upper lid 9 of the lead battery 10, the AI unit 1 is disposed at a place where the lead battery 10 is installed. Many are in the engine room or in an automobile such as a passenger compartment, and the alarm sound emitted by the buzzer is difficult to hear due to vehicle noise while driving. For this reason, the generation timing of the alarm sound generated by the AI unit 1 is set as follows, and the alarm sound is generated at a timing at which the user can easily hear the alarm sound, so that the alarm sound is reliably transmitted to the user. The AI unit 1 outputs a high level signal to the gate of the transistor that turns on the LED via the DA converter immediately after determining that the engine has stopped, and turns on the LED. A high-level signal is sent to the gate of the transistor that operates the buzzer via the DA converter of this type to generate a warning sound.

  At the timing of stopping the engine from the engine starting state, it is estimated that the user often performs a series of operations of getting out of the automobile, closing the door, locking the door, and leaving the automobile. Accordingly, when a warning sound is generated, if a certain time lag is provided from the timing when it is determined that the engine has stopped, there is a high possibility that an alarm will be transmitted to the user. In addition to the notification start timing, the notification continuation time by the buzzer warning sound is also an important factor of notification.

  As these specific times and times, it is preferable that the notification start by the buzzer is performed between 0 and 60 seconds after the engine is stopped. The notification duration is preferably 2 seconds or more, and it is preferable to continue notification for a maximum of several minutes. Moreover, since the optimal value of these time and time changes with the usage forms of a vehicle, what is necessary is just to be determined by each case according to the use of the lead battery 10. FIG. In addition, the lead battery 10 of this embodiment is a thing for general passenger cars, The alerting | reporting continuation time of the warning sound by a buzzer is set to about 30 seconds.

  According to the AI unit 1 of the present embodiment, in most cases, the alarm sound can be reliably transmitted to the user, but it is actually determined that the alarm sound is generated on the assumption that several missed hearings occur. The value Vth is preferably set slightly higher with a margin.

  On the other hand, in the display of the battery state of the lead battery 10 by the LED, the LED is turned on and displayed immediately after the engine is stopped. The time is about 5 minutes in this embodiment. Further, the AI unit 1 has an operation button 3 disposed on the operation display unit 2. This is because a user who hears a warning sound from the buzzer or desires to know the battery state can check the health state of the lead battery 10. That is, when there is an input by the operation button 3, the battery state is displayed by the LED so that the user can arbitrarily grasp the battery state. In the present embodiment, the LED indicating that the lead battery 10 needs to be replaced is lit using a red LED in order to alert the user.

  In addition, although omitted in FIG. 2, MP rewrites the time from when the EEPROM lead battery 10 is attached to the automobile (beginning of use) every certain time (for example, 2 weeks = 336 hours). Have been updated. In the initial setting process when the power is supplied from the lead battery 1 to the AI unit 1, the MP refers to the EEPROM, and if the time from when it was attached to the car at a predetermined address is written, it is written to the previous EEPROM. Since the power supply to the AI unit 1 was considered to have stopped between the initial time and the initial setting process at this time, the lead battery 10 was attached to the automobile while the time written in the EEPROM was Time is measured as if it has already passed.

(Action etc.)
Next, the operation and the like of the lead battery 10 of the present embodiment will be described focusing on the AI unit 1.

  The AI unit 1 measures the voltage of the lead battery 10 via the voltage measuring unit, and calculates the lowest voltage value Vst among the voltages measured at the time of starting the engine by the calculating unit (step 104), and then stored in the EEPROM. A voltage difference ΔVst between the lowest voltage value Vst0 at the start of the engine of the lead battery 10 in the non-degraded state and the lowest voltage value Vst of the lead battery 10 measured most recently is calculated (step 114). Next, the relationship between the time from the start of use of the lead battery 10 and the threshold value Vth is determined, and the use of the lead battery 10 is added to the formula of the determination threshold value that changes depending on the time from the start of use of the lead battery 10. The determination threshold value Vth at the present time is calculated by substituting the time from the start to the present time (step 115). Then, by determining whether or not the voltage difference ΔVst is larger than the determination threshold value Vth (step 116), if it is determined that the voltage difference ΔVst is large, the user is notified that the lead battery 10 has to be replaced after the engine stops ( Step 120).

  According to the AI unit 1 of the present embodiment, the health state of the lead battery 10 is determined from the lowest voltage value Vst0 calculated in the non-degraded state of the lead battery 10 and the latest lowest voltage value Vst. A lead battery that can determine the health condition of the lead battery 10 without using it, and uses a determination threshold value Vth that changes depending on the time from the start of use of the lead battery 10 (see FIG. 6). Ten health conditions can be determined early and appropriately.

  Further, the AI unit 1 of the present embodiment includes a nonvolatile EEPROM, and the lowest voltage value Vst0 that can be obtained only in the non-degraded state of the lead battery 10 is written in the EEPROM (step 110) and used for the deterioration determination. Along with (Step 112), every time a certain period of time has elapsed since the start of use of the lead battery 10, the elapsed time is written in the EEPROM. Therefore, for example, the AI unit 1 can be re-supplied even after the automobile on which the lead battery 10 is mounted is not moved for a long time (the lead battery 10 is not charged) and the power supply to the AI unit 1 is interrupted. The deterioration state of the lead battery 10 can be determined without losing the minimum voltage value Vst0 or the elapsed time data.

  In this embodiment, in order to simplify the explanation, an example in which the health state of the lead battery 10 is determined at two levels, i.e., good and requires replacement, using a determination threshold is shown. However, the determination is not limited to this, and for example, the determination may be performed by subdividing into three levels of good, caution, and exchange, or more. Further, in the present embodiment, an example is shown in which the threshold value of the determination threshold is represented by a straight line with respect to the time since the start of use of the lead battery 10, but the present invention is not limited to this. Or) or may be changed by a curve. Furthermore, a map or the like is not limited to a mathematical expression.

  Further, in the present embodiment, an example in which the deterioration determination of the lead battery 10 is performed by comparing the voltage difference Vst between the minimum voltage value Vst0 and the minimum voltage value Vst with the determination threshold value Vth is shown. For example, the ratio between the minimum voltage value Vst0 and the minimum voltage value Vst may be compared with a determination threshold value.

  Further, in the present embodiment, an example is shown in which the replacement of the lead battery 10 is displayed by turning on the red LED. However, when the lead battery 10 is further deteriorated, the lead battery 10 may be blinked. For this purpose, for example, a plurality of determination formulas having different inclinations may be prepared.

  Further, in the present embodiment, for the sake of simplicity, an example in which one minimum voltage value Vst0 is acquired and stored in the EEPROM has been described. However, a plurality of minimum voltage values Vst0 are stored in the non-degraded state of the lead battery 10. For example, an average value or mode value of the plurality of acquired minimum voltage values Vst0 may be calculated and stored in the EEPROM. In this way, the accuracy of deterioration determination by the AI unit 1 can be further increased.

  Further, in the present embodiment, the example in which the operation button 3 is pressed a predetermined number of times by a predetermined operation is shown as a starting point for determining that the lead battery 10 is in an undegraded state, in particular, the condition (1) described above. The MP may monitor whether or not the engine has been started for the first time, and when the determination is affirmative, it may be considered that the lead battery 10 is attached to the automobile, and that time may be used as a starting point for determining the condition (1) or the like. In this aspect, the starting point setting by the operation button 3 can be eliminated.

  In the present embodiment, the example in which the AI unit 1 as the battery state determination device is accommodated in the upper lid 9 of the lead battery 10 is shown, but the AI unit 1 may be used independently from the lead battery 10.

  The present invention provides a battery state determination device capable of quickly and appropriately determining the health state of a lead battery without using a current sensor, and a vehicle lead battery equipped with the battery state determination device. Since it contributes to the manufacture and sale of equipment and automotive lead-acid batteries, it has industrial applicability.

1 is an external perspective view of a lead battery according to an embodiment to which the present invention is applicable. It is a flowchart of the deterioration determination routine which the microprocessor of the AI unit accommodated in the lead battery of the embodiment executes. It is a graph which shows typically the voltage between terminals of a lead battery at the time of engine starting. It is a graph which shows the measured value when the voltage between terminals of the lead battery at the time of engine starting is measured for every predetermined time in time series. It is a graph which shows the minimum voltage value at the time of engine starting of the lead battery of an undeteriorated state, and the minimum voltage value at the time of engine start of the lead battery after deterioration. It is a graph which shows the relationship between the time from the start of use of the lead battery of an embodiment, and a judgment threshold.

Explanation of symbols

1 AI unit (voltage measurement means, calculation means, state determination means, battery state determination device)
10 Lead battery

Claims (5)

In a battery state determination device for determining the health state of a lead battery,
Voltage measuring means for measuring the voltage of the lead battery;
A calculating means for calculating a minimum voltage value at the time of discharging the lead battery among the voltages measured by the voltage measuring means;
A state in which the health state of the lead battery is determined from the lowest voltage value calculated in the non-deteriorated state of the lead battery by the calculating means and the latest minimum voltage value calculated in the non-deteriorated or deteriorated state of the lead battery. A determination means;
The state determination means determines a health state of the lead battery using a determination threshold value for deterioration determination that changes with time from the start of use of the lead battery. apparatus.   The lead battery is an automotive lead battery, and the minimum voltage value calculated by the calculating means is a minimum voltage value among discharge voltages of the lead battery when driving a cell motor for starting an engine. The battery state determination device according to claim 1.   Time measuring means for measuring time, the state determining means from the time from the start of use of the lead battery measured by the time measuring means, the time from the start of use of the lead battery and the determination threshold The battery state determination apparatus according to claim 2, wherein the determination threshold value is calculated using a map or a mathematical expression that defines a relationship.   The battery state detection device according to claim 3, further comprising a non-volatile memory, wherein the time measuring means stores a time from the start of use of the lead battery in the memory every time a predetermined time elapses.   The lead battery for motor vehicles provided with the battery state determination apparatus of any one of Claim 1 thru | or 4.

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