JP2007173044A - Charge controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charge controller which can be prevented from acceleration of the deterioration of a battery, by deducing the gassing voltage which is the voltage at which deterioration of charging efficiency starts and by correcting the charge completion voltage, on the basis of battery conditions. <P>SOLUTION: When battery charge is started by an alternator, charge/discharge current of the battery, terminal voltage, and temperature of the battery solution are detected to compute the theoretical internal resistance by using the solution temperature and degree of battery deterioration is evaluated from this value and measured internal resistance to deduce the gassing voltage with this degree of deterioration (steps 101 to 105). After determining whether the deduced gassing voltage Va is correct (steps 106 to 115), if the difference between the deduced gassing voltage Va and an objective charge voltage presently targeted is larger than the predetermined value, target charge voltage at normal charging and that of forced charging are corrected, and is stored in a memory (steps 116 to 119). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a charge management device that controls charging of a battery that supplies power to in-vehicle electrical components and the like.

  BACKGROUND ART An electronic control device (hereinafter referred to as an ECU) for a vehicle performs electronic control of the vehicle by exchanging signals with a control mechanism of the vehicle. For example, an engine ECU includes a sensor mounted on the vehicle. Information such as vehicle speed, engine speed, and air inflow detected by the group is input, and the engine ECU performs predetermined calculation processing based on these information, and the calculation results (for example, fuel injection amount and bypass air) A signal for controlling the amount) is sent to a control mechanism such as an electric throttle or a starter injection valve installed in the vehicle to control the fuel injection amount and the inflow air amount.

  There are many such electronic control devices in the vehicle, for example, the engine ECU as described above, a charge control ECU that controls charging of the power source, an eco-run ECU that drives the vehicle while driving and stopping the engine, doors and locks A body ECU that performs control, an automatic transmission (AT) control ECU, an air bag ECU, a security ECU that generates an alarm when a theft occurs or an event that may cause the theft is installed .

  In this way, the number of on-board electrical components has increased rapidly due to the development of electronic control accompanying the spread of automobiles and the spread of on-board parts due to the need for convenience, comfort, and safety. The charging control according to the battery voltage and the battery liquid temperature is necessary.

On the other hand, since the battery is vulnerable to overcharge and the battery life is shortened when overcharged, when charging the battery, the completion of charging is detected, and charging is automatically stopped after the completion of charging.
However, since the charging characteristics of the battery vary depending on the ambient temperature at which the battery is charged, conventionally, the charging end voltage is corrected according to the battery liquid temperature or the outside air temperature (see, for example, Patent Document 1).
JP-A-5-76140

In general, as the charge / discharge characteristics of the battery, when the battery is new, when the battery capacity is approximately 80% or less of the actual capacity, the rate of increase of the capacity with respect to the charging current is approximately 100%, but the battery capacity is approximately 80% of the actual capacity. If it exceeds%, gassing occurs, and charging efficiency gradually decreases.
In this gassing, the voltage of the electrode rises as the battery is charged and its capacity increases, and when the electrode voltage rises above a predetermined value, the water in the battery fluid is electrolyzed by the charging current. It is a phenomenon that occurs.

  As the battery deteriorates, the time at which gassing starts, that is, the time at which charging efficiency begins to decline gradually becomes earlier or the charging efficiency declines abruptly. Decreases, and the capacity does not increase to the actual capacity, that is, the capacity when new.

  As described above, conventionally, in the charge management device that controls the charging of the battery, the charging end voltage is corrected according to the battery liquid temperature or the outside air temperature. When the voltage reaches a voltage, the battery charge end voltage (gassing occurrence voltage), which is the voltage at which charging efficiency begins to decrease, changes. Simply correcting the charge end voltage according to the battery liquid temperature or the outside air temperature will cause battery deterioration due to gassing. Therefore, it is necessary to accurately estimate the gassing occurrence voltage and reflect it in the charge control.

  The present invention has been made in view of the above-described problem. Based on the state of the battery, the charging end voltage is estimated by correcting the charging end voltage by estimating the gassing occurrence voltage, which is the voltage at which the reduction in charging efficiency starts to occur. An object of the present invention is to provide a charge management device capable of preventing deterioration of the battery.

In order to achieve the above object, the charge management device (1) according to the present invention includes:
Charging control means for controlling charging of the battery;
A gassing occurrence voltage estimating means for estimating a gassing occurrence voltage that is a voltage at which a decrease in charging efficiency starts to occur based on the state of the battery;
Charging voltage correcting means for correcting a voltage at which the charging control means terminates charging based on the gassing occurrence voltage.

In addition, the charge management device (2) according to the present invention includes a charge management device (1),
A battery deterioration degree detecting means for detecting the battery deterioration degree;
The gassing occurrence voltage estimation means estimates the gassing occurrence voltage based on the battery deterioration degree.

Furthermore, the charge management device (3) according to the present invention includes a charge management device (1),
The gashing occurrence voltage estimating means starts the gashing occurrence voltage determination process when the battery voltage becomes a predetermined voltage lower than the gashing occurrence estimated voltage, and calculates the current value from when the start condition is satisfied until the gashing occurrence estimated voltage is reached. The integration is performed, and the gashing determination ratio Ra is calculated based on a difference between the integrated current value and the estimated gassing occurrence voltage and the predetermined voltage.

Further, the charge management device (4) according to the present invention is the charge management device (3),
The gashing occurrence voltage estimation means integrates the current value until the battery voltage reaches a predetermined voltage higher than the gashing occurrence estimated voltage, and based on a difference between the accumulated current value and the gashing occurrence estimated voltage and the predetermined voltage. A determination ratio Rb is calculated, and whether the gashing estimated voltage is correct or not is determined based on the ratio of the gashing determination ratio Ra to the gashing determination ratio Rb and the theoretical ratio R0.

Furthermore, the charge management device (5) according to the present invention includes any one of the charge management devices (1) to (4).
The charging voltage correcting means performs a charging end voltage correcting process by forcibly charging the battery,
The charge management device (6) according to the present invention is any one of the charge management devices (1) to (4).
When the difference between the gassing occurrence voltage and the current charge end voltage is greater than or equal to a predetermined value, the charge voltage correction means corrects the charge end voltage.

Moreover, the estimation method (1) of the gassing generation voltage according to the present invention is as follows:
Estimating a gassing occurrence voltage, which is a voltage at which a decrease in charging efficiency occurs, based on a battery state;
When the charging control of the battery is performed so as to include the gassing occurrence voltage estimated in the above step, the charging efficiency when the charging voltage is equal to or lower than the gasching occurrence voltage, and the charging voltage is equal to or higher than the gasching occurrence voltage And verifying the validity of the gassing occurrence voltage estimated in the above step based on the charging efficiency.

  According to the charge management devices (1), (2), and (6) according to the present invention, based on the state of the battery, a gashing occurrence voltage that is a voltage at which a decrease in charging efficiency starts to occur is estimated, and this gashing occurrence occurs. Since the voltage for ending the charging of the battery is corrected based on the voltage, it is possible to accurately prevent battery deterioration. In addition, according to the charge management devices (3) and (4) according to the present invention, since the suitability of the estimated gassing occurrence voltage is determined, the charge end voltage can be corrected by the accurate gassing occurrence voltage. According to the charge management device (5) of the present invention, the charge end voltage can be periodically corrected by forcibly charging the battery.

  Furthermore, according to the estimation method (1) of the gassing occurrence voltage according to the present invention, based on the charging efficiency when the charging voltage is equal to or lower than the gasching occurrence voltage and the charging efficiency when the charging voltage is equal to or higher than the gasching occurrence voltage. Thus, since the validity of the estimated gassing occurrence voltage is verified, the gassing occurrence voltage can be accurately estimated.

Hereinafter, embodiments of the charge management device of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a charging system including a charge management device according to the present invention. This system includes a charge management device 1, a battery 2, and an alternator 3, which are connected by a communication line 4 and a power line 5, respectively. Has been.

  The charge management device 1 detects the state of the battery 2 and controls the power generation of the alternator 3. The CPU 11, the ROM (Read Only Memory) 12, the RAM (Random Access Memory) 13, the EEPROM (Electrically Erasable and Programmable ROM). ) 14, a communication device (not shown), an input / output circuit (not shown), and the like. The CPU 11 controls each part of the hardware of the charge management device 1 and executes various programs such as charge control based on a program stored in the ROM 12, and the ROM 12 includes programs such as a charge control program and a target charge voltage correction program. Data such as theoretical values indicating the relationship between the liquid temperature of the mounted battery and the internal resistance is stored. The RAM 13 is composed of an SRAM or the like and stores temporarily generated data, and the EEPROM 14 stores a corrected target charging voltage or the like.

On the other hand, a current detector 21 is connected in series to the battery 2 and a voltage detector 22 is connected in parallel. Further, a battery liquid temperature detector 23 for detecting the battery liquid temperature is provided in the battery 2.
The current detector 21 detects the charge / discharge current of the battery 2, the voltage detector 22 detects the terminal voltage of the battery 2, and these detection outputs are output to the charge management device 1 together with the detection output of the battery liquid temperature detector 23. Entered.
The alternator 3 is driven by an engine (not shown) to charge the battery 2 and supply electric power to other electric loads of the vehicle.

Next, the operation when the charge management device 1 corrects the target charge voltage will be described with reference to the flowchart of FIG.
When the ignition of the vehicle is turned on and charging of the battery 2 is started by the alternator 3, the CPU 11 of the charge management device 1 starts a target charging voltage correction program shown in the flowchart of FIG. Detect (step 101).
That is, the CPU 11 detects the charge / discharge current, the terminal voltage, and the battery liquid temperature of the battery 2 based on the outputs of the current detector 21, the voltage detector 22, and the battery liquid temperature detector 23.

Next, the CPU 11 calculates the theoretical internal resistance of the battery 2 based on the table indicating the relationship between the liquid temperature and the internal resistance stored in the ROM 12 (step 102), and then calculates the deterioration degree of the battery 2 (step 102). Step 103).
That is, as shown by the solid line in FIG. 3, the ROM 12 stores a theoretical value curve indicating the relationship between the liquid temperature and the internal resistance when the battery 2 is new, and therefore the theoretical value curve based on the detected liquid temperature is stored. The internal resistance is calculated, and the difference ε between the calculated theoretical internal resistance and the actually measured internal resistance is obtained as the battery deterioration level.

After calculating the degree of deterioration, the CPU 11 determines whether or not the calculated degree of deterioration ε is greater than the predetermined value ε0 (step 104). If it is determined that the degree of deterioration ε is smaller than the predetermined value ε0, the program is terminated. If it is determined that the deterioration degree ε is greater than the predetermined value ε0, the gassing occurrence voltage is estimated from the deterioration degree ε (step 105).
That is, as shown in FIG. 4, the ROM 12 stores a table showing the relationship between the deterioration degree ε of the battery 2 and the gassing occurrence voltage, and the gassing occurrence voltage estimated value Va is obtained based on this table.

  Next, the CPU 11 determines whether or not the terminal voltage V of the battery 2 at that time is larger than a predetermined value Vb (step 106), and as shown in FIG. It is determined that the voltage V is higher than the predetermined value Vb from a state where the voltage V is lower than the predetermined value Vb (if it is known that the battery is charged, it is determined that the terminal voltage V has reached the predetermined value Vb. 5), as shown in FIG. 5B, the integration of the current value of the charging current flowing through the battery 2 is started based on the output of the current detector 21 (step 107). The predetermined value Vb may be a constant value or a value obtained by subtracting the predetermined value from the estimated gassing voltage Va.

  When the integration of the current value is started, the CPU 11 determines whether or not the terminal voltage V of the battery 2 at that time is larger than the estimated gassing voltage Va (step 108), as shown in FIG. When it is determined that the terminal voltage V of the battery 2 has become larger than the estimated gassing voltage Va, the gasching ratio Ra (= ∫Ia / Vb) when the voltage is lower than the estimated gassing voltage Va, that is, A ratio between the current integrated value and the voltage value up to the time is obtained (step 109). Note that Va, Va-Vb, or the like may be used in addition to Vb as the voltage for obtaining the gassing ratio Ra.

Next, as shown in FIG. 5C, the CPU 11 again starts integrating the current value flowing through the battery 2 based on the output of the current detector 21 (step 110), and then the battery 2 at that time It is determined whether or not the terminal voltage V is greater than a predetermined value Vc (step 111). The predetermined value Vc may be a constant value or a value obtained by adding a predetermined value to the estimated gassing voltage Va.
As shown in FIG. 5A, when it is determined that the terminal voltage V of the battery 2 is greater than the predetermined value Vc, the CPU 11 has a gassing ratio Rb (= ∫) when the voltage is higher than the estimated gassing voltage Va. Ib / Va), that is, the ratio between the current integrated value and the voltage value up to that point (step 112). Note that Vc, Vc-Va, or the like may be used in addition to Va as a voltage for obtaining the gassing ratio Rb.
At this time, if the estimated gassing voltage Va is correct, as shown in FIGS. 5D and 5E, the gasching ratio is increased until the terminal voltage V of the battery 2 reaches the estimated gassing voltage Va. Ra is equal to the theoretical value, and when the terminal voltage V of the battery 2 exceeds the estimated gassing voltage Va, the gassing has occurred, and the gassing ratio Rb increases.

Next, an actual measurement ratio R (= Rb / Ra) of the gashing ratio, which is the ratio of the gashing ratio, is calculated from the gashing ratio Ra and the gashing ratio Rb obtained above (step 113), and the theoretical ratio of gashing R0 is described later. After calculating from the above (step 114), it is determined whether or not the difference between the gassing ratio R and the gassing theoretical ratio R0 is larger than a predetermined value (step 115).
Since the battery voltage increases with a small charging current as the battery liquid temperature increases, the theoretical ratio of gassing, that is, the gashing ratio when the battery is new, changes with temperature as shown in FIG. Accordingly, a table indicating the relationship between the battery liquid temperature and the theoretical ratio of gassing is stored in the ROM 12, and the CPU 11 calculates the theoretical ratio of gashing based on the detected battery liquid temperature and the above table value.
As shown in FIG. 7, a table showing the relationship between the degree of deterioration and the theoretical ratio of gassing can be stored in the ROM 12, and the theoretical ratio of gashing can be calculated based on this table.

  If it is determined in step 115 that the difference between the measured ratio R of gashing and the theoretical ratio R0 of gashing is greater than a predetermined value, the CPU 11 determines that the estimated value Va generated in step 105 is incorrect. Exit the program. At this time, the estimated value of the generated gassing voltage estimated after the next time may be corrected according to the amount of deviation between the measured ratio of gashing and the theoretical ratio of gashing.

On the other hand, if it is determined in step 115 that the difference between the actual ratio R of gashing and the theoretical ratio R0 of gashing is smaller than the predetermined value, the CPU 11 determines that the estimated value Va of gashing estimated in step 105 is correct, and the gashing. It is determined whether or not the difference between the generated voltage estimated value Va and the currently set target charging voltage is greater than or equal to a predetermined value (step 116).
If the CPU 11 determines that the difference between the estimated gassing voltage Va and the currently set target charging voltage is within a predetermined value, the CPU 11 determines that the target charging voltage does not need to be changed and ends the program.

Further, when it is determined that the difference between the estimated gassing voltage Va and the target charging voltage that is the currently set normal charging value is greater than or equal to a predetermined value, the CPU 11 needs to change the target charging voltage. The target charging voltage during normal charging is corrected to the estimated value Va of the gashing generation (step 117), and the target charging voltage during forced charging is corrected to the added value of the estimated gassing voltage Va value and the predetermined voltage value. After (step 118), the corrected target charging voltage value is stored in the EEPROM 14 (step 119).
Note that forced charging includes refresh charging, that is, for removing sulfation adhering to the electrode by performing gassing to the battery, and forcibly charging for supplementary charging. It is desirable to change the predetermined voltage value to be added.

  As described above, the gassing occurrence voltage is estimated based on the degree of battery deterioration. However, the gassing occurrence voltage estimated due to variations in the sensor or abnormal internal resistance of the battery may be incorrect. By determining whether or not is correct, an accurate gassing occurrence voltage can be obtained, and the target charging voltage can be set correctly.

In the above embodiment, the target charging voltage is corrected when charging of the battery 2 is started by the alternator 3. However, since the charging timing of the battery is unknown, charging is forcibly performed. The target charging voltage can also be corrected by the following, and the operation in the case of forcibly charging will be described below with reference to the flowchart of FIG.
The CPU 11 of the charge management apparatus 1 periodically starts the target charge voltage correction program shown in the flowchart of FIG. 8, but the operations of Step 201 to Step 205 and Steps 215 to 222 are the same as those in Step 101 of the flowchart of FIG. 2. Since the operation is the same as that of Step 105 and Step 112 to Step 119, detailed description is omitted, and only the operation of Step 207 to Step 214 will be described.

  When the gassing occurrence voltage is estimated from the deterioration degree ε in step 205, the CPU 11 starts forced charging by controlling the alternator 3 (step 206), and then the terminal voltage V of the battery 2 at that time is greater than the predetermined value Vb. (Step 207), and if it is determined that the terminal voltage V of the battery 2 is greater than the predetermined value Vb, it is determined whether or not the forced charging prohibition condition is not satisfied (Step 208). The predetermined value Vb may be a constant value as described above, or may be a value obtained by subtracting the predetermined value from the estimated gassing occurrence voltage Va.

  When the forced charging prohibition condition is satisfied by turning on the high load electrical equipment or at high speed acceleration, the CPU 11 determines that the forced charging prohibition condition is not satisfied by stopping the forced charging and terminating the program. If so, the CPU 11 starts integrating the current value of the charging current flowing through the battery 2 based on the output of the current detector 21 (step 209).

  When the integration of the current value is started, the CPU 11 determines whether or not the terminal voltage V of the battery 2 at that time is larger than the estimated gassing voltage Va (step 210), and the terminal voltage V of the battery 2 is the gashing. When it is determined that the generated voltage is smaller than the estimated value Va, the process returns to step 208 to determine again whether the forced charging prohibition condition is not satisfied.

On the other hand, if it is determined in step 210 that the terminal voltage V of the battery 2 has become larger than the estimated gassing voltage Va, the CPU 11 calculates the gasching ratio Ra when the voltage is lower than the estimated gas generation value Va (step). 211).
Next, the CPU 11 again determines whether or not the forced charge prohibition condition is not established (step 212). When it is determined that the forced charge prohibition condition is satisfied, the forced charge is stopped and the program is terminated. When it is determined that the forced charging prohibition condition is not established, the integration of the current value of the charging current flowing through the battery 2 is started based on the output of the current detector 21 (step 213).

When integration of the current value is started, the CPU 11 determines whether or not the terminal voltage V of the battery 2 at that time is larger than the voltage Vc (step 214), and the terminal voltage V of the battery 2 is If it is determined that the voltage Vc is smaller than the voltage Vc, the process returns to step 212 to determine again whether the forced charging prohibition condition is not established. If it is determined that the terminal voltage V of the battery 2 is greater than the voltage Vc, the estimated gassing occurrence voltage Va The gassing ratio Rb when the voltage is higher than that is calculated (step 215). The predetermined value Vc may be a constant value as described above, or may be a value obtained by adding the predetermined value to the estimated gassing voltage Va.
As described above, the target charging voltage can be periodically corrected by forcibly charging the battery, and it is always determined whether the forced charging prohibition condition is not satisfied. The target charging voltage correction process can be stopped at the time of high speed acceleration or the like.

  Further, in the above embodiment, it is determined whether or not the gassing occurrence voltage estimated based on the battery deterioration degree is correct. However, it is simply assumed that the gassing generation voltage estimated based on the battery deterioration degree is correct. It is also possible to correct the charging voltage. Hereinafter, the operation when the target charging voltage is simply corrected will be described with reference to the flowchart of FIG.

  When the ignition of the vehicle is turned on and charging of the battery 2 is started by the alternator 3, the CPU 11 of the charge management device 1 starts the target charging voltage correction program shown in the flowchart of FIG. 9 and detects the state of the battery 2 After (Step 301), the theoretical internal resistance of the battery 2 is calculated (Step 302), and the deterioration degree of the battery 2 is calculated (Step 303).

  Next, the CPU 11 determines whether or not the calculated degree of degradation ε is greater than the predetermined value ε0 (step 304). If the CPU 11 determines that the degree of degradation ε is smaller than the predetermined value ε0, the CPU 11 ends the program, and the degree of degradation ε Is determined to be greater than the predetermined value ε0, the gassing occurrence voltage Va is determined from the degradation degree ε (step 305), and then the difference between the gassing generation voltage Va and the currently set target charging voltage is greater than or equal to the predetermined value. Is determined (step 306).

  If it is determined that the difference between the gassing occurrence voltage Va and the currently set target charging voltage is within a predetermined value, the CPU 11 determines that the target charging voltage does not need to be changed and ends the program. If the CPU 11 determines that the difference between the gassing occurrence voltage Va and the currently set target charging voltage is greater than or equal to a predetermined value, the CPU 11 determines that the target charging voltage needs to be changed, and the target charging voltage during normal charging. Is corrected to the gassing generation voltage Va (step 307), and the target charging voltage at the time of forced charging is corrected to an addition value of the gassing generation voltage Va and a predetermined voltage value (step 308), and then the corrected target charging voltage value is calculated. The data is stored in the EEPROM 14 (step 309).

As described above, it is possible to reduce the load of the target charging voltage correction processing of the CPU by simply correcting the target charging voltage assuming that the gassing occurrence voltage obtained from the battery deterioration level is correct.
In this embodiment, when the charging of the battery 2 is started, the target charging voltage correction process is started. However, as in the second embodiment, the target charging voltage can be simply set by forcibly charging. The correction process can also be performed.

  In the present invention, the definition of the end-of-charge voltage (gassing occurrence voltage) in a broad sense does not have to be the voltage at which gassing occurs (the lower limit voltage at which gassing starts to occur), and may be within the range of the voltage at which gassing occurs. In other words, it is a lower limit voltage (gasing occurrence lower limit voltage) at which gassing starts to occur.

  “Gassing occurs” means that “charging efficiency is reduced”, but how much it falls to determine that gashing is occurring is, for example, the total voltage that the battery can take Determining that gassing has occurred when the charging efficiency has deteriorated by 20% or more with respect to the average value of the charging efficiency in the middle part of the range (in the case of a 16V battery, the range is 5V to 10V). Can do. It should be noted that the calculation method at this time and the criterion for determining that the condition has deteriorated (20% in the above example) can be changed as appropriate.

It is a block diagram which shows the structure of the charging system containing the charge management apparatus of this invention. It is a flowchart which shows an effect | action when correct | amending a target charging voltage. It is a figure which shows the relationship between the liquid temperature of a battery, and internal resistance. It is a figure which shows the relationship between the deterioration degree (epsilon) of a battery, and gassing generation voltage. It is a figure which shows the waveform of each part in the case of correcting a target charging voltage. It is a figure which shows the relationship between the liquid temperature of a battery, and the theoretical ratio of gassing. It is a figure which shows the relationship between the deterioration degree of a battery, and the theoretical ratio of gassing. It is a flowchart which shows an effect | action in case correction | amendment of a target charging voltage is performed by forcing charging. It is a flowchart which shows an effect | action when correct | amending a target charging voltage simply.

Explanation of symbols

1 Charge management device 11 CPU
12 ROM
13 RAM
14 EEPROM
2 Battery 21 Current detector 22 Voltage detector 23 Battery liquid temperature detector 3 Alternator 4 Communication line 5 Power line

Claims (7)

Charging control means for controlling charging of the battery;
A gassing occurrence voltage estimating means for estimating a gassing occurrence voltage that is a voltage at which a decrease in charging efficiency starts to occur based on the state of the battery;
A charge management device comprising: charge voltage correction means for correcting a voltage at which the charge control means ends charging based on the gassing occurrence voltage. In the charge management device according to claim 1,
A battery deterioration degree detecting means for detecting the battery deterioration degree;
The charging management device, wherein the gassing generation voltage estimation means estimates the gassing generation voltage based on the battery deterioration degree. In the charge management device according to claim 1,
The gashing occurrence voltage estimating means starts the gashing occurrence voltage determination process when the battery voltage becomes a predetermined voltage lower than the gashing occurrence estimated voltage, and calculates the current value from when the start condition is satisfied until the gashing occurrence estimated voltage is reached. A charge management device that performs integration and calculates a gashing determination ratio Ra based on a difference between the integrated current value and estimated gassing occurrence voltage and the predetermined voltage. In the charge management device according to claim 3,
The gashing occurrence voltage estimating means integrates current values until the battery voltage reaches a predetermined voltage higher than the gashing occurrence estimated voltage, and performs gashing based on the accumulated current value and the difference between the gashing occurrence estimated voltage and the predetermined voltage. A charge management device that calculates a determination ratio Rb and determines whether the estimated gashing voltage is correct or not based on the ratio of the gashing determination ratio Ra to the gashing determination ratio Rb and the theoretical ratio R0. In the charge management device according to any one of claims 1 to 4,
The charge management device, wherein the charge voltage correction means performs a charge end voltage correction process by forcibly charging the battery. In the charge management device according to any one of claims 1 to 4,
The charge management device, wherein the charge voltage correction means corrects the charge end voltage when a difference between the gassing occurrence voltage and the current charge end voltage is equal to or greater than a predetermined value. Estimating a gassing occurrence voltage, which is a voltage at which a decrease in charging efficiency occurs, based on a battery state;
When the charging control of the battery is performed so as to include the gassing occurrence voltage estimated in the above step, the charging efficiency when the charging voltage is equal to or lower than the gasching occurrence voltage, and the charging voltage is equal to or higher than the gasching occurrence voltage And a step of verifying the validity of the gassing occurrence voltage estimated in the above step based on the charging efficiency.

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