JP2000357541A - Battery management device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To realize fail-safe when a voltage sensor as a means for detecting a charged amount and a battery abnormality has failed. SOLUTION: The SOC of a battery unit corresponding to a failed voltage detector 12 is estimated from the SOCs of other battery units. Further, when a failure of the voltage detector 12 is detected, the charge / discharge current is suppressed, and even if an abnormality occurs in the battery unit corresponding to the failed voltage detector 12, the generation of Joule heat is suppressed. So that

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery management device for managing a charge / discharge state of a battery, and more particularly to an appropriate management when a failure occurs in a battery electromotive voltage detection system.

[0002]

2. Description of the Related Art A battery management device for monitoring the state of charge of a battery is used, for example, for a battery mounted on a hybrid vehicle. A hybrid vehicle runs by rotating wheels by a vehicle driving motor and an engine. In addition to the driving motor, a generator driven by an engine and a battery are mounted, and the driving motor is driven by electric power from the battery. While being driven, the battery is charged by the electric power from the generator.

[0003] The charged amount of a battery is expressed by SOC (state of charge: State).
of Charge). As a method of detecting the SOC, there is a method of utilizing the correlation between the voltage-current characteristics (IV characteristics) of the battery during charging (or discharging) and the SOC. In this detection method, S
A strong correlation that appears in a charged state where the OC is high or a discharged state where the SOC is low is used. For example, when the SOC is 80% or more or 20% or less, the actual SOC (actual SOC) can be accurately determined from the IV characteristics. Can be determined. However, since the correlation is weak when the SOC is intermediate, it cannot be used for determining the SOC when the SOC is in an intermediate region such as between 20% and 80%.

As a method of detecting the SOC in the intermediate region,
There is a detection method by integrating the charge / discharge current amount. In normal traveling, the driving of the motor and the driving of the generator are controlled such that the integrated SOC obtained by the current integrating method becomes a predetermined value (for example, about 50%). Incidentally, in this method, the actual SO obtained when a strong correlation between the above-described IV characteristic and SOC occurs (when a so-called IV determination occurs) is obtained.
By resetting the integrated SOC to C, errors that can be accumulated by the integration are eliminated. As another method of detecting the SOC in the intermediate region, a method of determining the relationship between the integrated SOC and the battery electromotive voltage (SOC-electromotive voltage characteristic) and determining the SOC from the electromotive voltage of the battery unit based on this characteristic is also available. is there.

[0005] The battery management device uses the S
The OC is monitored, for example, to suppress the occurrence of an overdischarge state that causes deterioration of the performance of the battery, or to detect an overdischarge state and take appropriate measures.

[0006] Conventionally, the battery management device has a voltage sensor for detecting each electromotive voltage of the battery unit.
This voltage sensor has been used exclusively for performing the above-described IV determination and determining the SOC using the SOC-electromotive force characteristics. Further, abnormality detection of each battery unit can be performed using a voltage sensor. For example,
An increase in internal resistance caused by performance deterioration of the battery unit can be detected by the voltage sensor, and abnormality of the battery can be determined.

On the other hand, in the conventional battery management device, a temperature switch is provided as means for detecting an abnormality of each battery unit. This temperature switch is a resistor provided in each battery unit and connected in series between each battery unit. The temperature switch is formed of a resistor whose resistivity changes in accordance with a rise in temperature, and detects a heat generation due to an abnormality of the battery unit based on the change in the resistance. Since the change in the resistivity is extremely large, even if abnormal heat generation occurs only in a part of a large number of battery units, a change in the resistance value of the temperature switches connected in series across all the battery units is easily detected. Therefore, there is an advantage that only one resistance detection circuit is basically required.

In addition to the temperature switch, a thermistor is also provided as means for detecting the temperature at a representative point of the battery.

[0009]

When the temperature switch is abolished for the purpose of simplifying the structure of the battery management device and reducing the cost, the abnormality detection of the battery unit is performed only by the method using the voltage sensor. Become. Therefore,
When the voltage sensor breaks down, there is a problem that abnormality detection of the battery unit may not be performed.

[0010] Further, if the voltage sensor fails, there arises a problem that the detection of the SOC is hindered and a problem that the overdischarge state cannot be prevented or detected.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a battery management apparatus which solves the above problems, eliminates the need for a temperature switch, and protects a battery even if a voltage sensor fails.

[0012]

A battery management device according to the present invention is provided with a voltage sensor for detecting an electromotive voltage of each battery unit of at least one battery unit, and the voltage sensor detects the voltage. A battery management device that detects an abnormality of the battery unit based on an electromotive voltage, and a voltage sensor failure detection unit that detects a failure of the voltage sensor, and when a failure of any one of the voltage sensors is detected, Battery current suppressing means for suppressing the battery current more than in a normal state.

A voltage sensor provided for each battery unit has a function of detecting the internal resistance of the corresponding battery unit and monitoring the occurrence of an abnormality such as performance deterioration of the battery unit. Therefore, when the voltage sensor fails, it becomes impossible to detect the abnormality of the corresponding battery unit. According to the present invention, when the voltage sensor failure detection unit detects a failure of any one of the voltage sensors, the battery current suppression unit suppresses the battery current, that is, the charge / discharge current, from a normal state. Thus, even if the corresponding battery unit has an abnormality, heat generation due to Joule heat is suppressed, and further deterioration of the battery unit is prevented. In this device, the battery is not disconnected from the system when a failure occurs in the voltage sensor, and is continuously used while suppressing the charge / discharge current. As a result, control with reduced influence on a system using the battery is realized.

Another battery management device according to the present invention is provided with a voltage sensor for detecting an electromotive voltage of each battery unit of a battery including a plurality of battery units, and based on the electromotive voltage detected by the voltage sensor. A battery management device for detecting the amount of charge of each of the battery units, comprising: a voltage sensor failure detecting means for detecting a failure of the voltage sensor; and a failure voltage when any one of the voltage sensors is failed. And a charge amount estimating means for estimating the charge amount of the battery unit corresponding to the sensor based on the charge amount detected for the remaining non-fault voltage sensor.

The voltage sensor provided for each battery unit is used for managing the amount of charge of the corresponding battery unit, that is, the SOC. Therefore, if the voltage sensor fails,
The function of detecting and preventing overcharge and overdischarge is impaired. Here, the SOC of the battery unit corresponding to the voltage sensor that has not failed can be detected. According to the present invention,
When the voltage sensor failure detecting means detects a failure of any of the voltage sensors, the charged amount estimating means estimates the SOC of the battery unit corresponding to the failed voltage sensor from the SOC of the battery unit corresponding to the non-failed voltage sensor. Then, battery management is performed using the estimated SOC. In this device, the battery is continuously used without disconnection from the system when a failure occurs in the voltage sensor. As a result, control with reduced influence on a system using the battery is realized.

In a preferred aspect of the present invention, a voltage sensor for detecting an electromotive voltage is provided for each battery unit of a battery comprising a plurality of battery units, and each of the battery sensors is detected based on the electromotive voltage detected by the voltage sensor. A battery management device that detects an abnormality of a battery unit and a charged amount, and a voltage sensor failure detection unit that detects a failure of the voltage sensor, and when a failure of any of the voltage sensors is detected, Battery current suppressing means for suppressing battery current, and when a failure of any one of the voltage sensors is detected, the amount of charge of the battery unit corresponding to the failed voltage sensor is detected for the remaining non-failed voltage sensor The battery management device includes a storage amount estimating unit that estimates based on the storage amount.

Further, another preferred aspect of the present invention is a battery management device, wherein the battery current suppressing means suppresses the battery current based on charge / discharge power of the battery.

According to another aspect of the present invention, there is provided a battery management device for obtaining an integrated storage amount based on an integration of a battery current, and for correcting the integrated storage amount based on an electromotive voltage of a battery detected by a voltage sensor. And a voltage sensor failure detecting means for detecting a failure of the voltage sensor, and controlling the charge amount to be larger than the discharge amount when the failure of the voltage sensor is detected. Charge promotion means for shifting the state of charge of the battery toward full charge, full charge detection means for detecting the full charge of the battery based on the battery temperature during charging, and full charge detection by the full charge detection means. It is characterized in that it has an integrated storage amount reset means for resetting the integrated storage amount to a fully charged state when it is detected.

As a method of correcting the accumulated charge amount using the output of the voltage sensor, there are methods based on IV determination and SOC-electromotive force characteristics, but the voltage sensor of one of the battery units or the voltage of the entire battery is measured. If the voltage sensor malfunctions, the SOC of the battery unit or the entire battery cannot be corrected by those methods.
According to the present invention, when the voltage sensor failure detecting means detects a failure of any one of the voltage sensors, the charge accelerating means controls the charge amount to be larger than the discharge amount, and the actual S
Let the OC go to full charge. The fact that the actual SOC is in the fully charged state is detected by the full charge detecting means. The full-charge detecting means detects, for example, a temperature change (dT / dt:
(T is the battery temperature, t is the time) reaches a predetermined value, and it is determined that the SOC is fully charged. The integrated power storage amount reset unit resets the integrated SOC to a full charged state when the full charged state of the actual SOC is detected. Thus, according to the present invention, the deviation between the actual SOC and the integrated SOC is eliminated, the accuracy of the SOC management of the battery using the integrated SOC is maintained, and overdischarge can be prevented.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [Embodiment 1] Hereinafter, an embodiment (hereinafter, referred to as an embodiment) of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a system in which the battery management device of the present invention is applied to a hybrid vehicle. The battery 10 is composed of a number of battery cells. In the present embodiment, the battery 10 is a nickel-metal hydride (Ni-MH) battery, and a single block (battery unit) includes 20 battery cells.
It has an output voltage of about 300 V obtained by connecting 12 blocks and connecting 240 battery cells in series.

The voltage of each block of the battery 10 and the overall voltage are measured by a voltage detector 12, and the battery ECU 1
4 is supplied. The battery ECU 14 is connected to a temperature sensor 16 for detecting a temperature at a representative point of the battery as a battery temperature, and a current detector 18 for detecting a battery current. It is supplied to the ECU 14.

The battery ECU 14 determines the amount of power stored in the battery 10 (SO
C) is detected and supplied to the HVECU 20. Note that the battery ECU 14 detects overdischarge in the battery cells based on the voltage value for each block supplied from the voltage detector 12.

The HVECU 20 controls the load 22 based on a torque command determined based on information such as an accelerator opening, a brake depression amount, and a vehicle speed. Load 22
Is composed of an inverter, a motor, and the like, and converts DC power from the battery 10 into AC current by the inverter to drive the motor. And the HVECU 20
The operation of the inverter is controlled by the control signal from the motor, so that the motor outputs a torque that matches the torque command. In addition, regenerative braking is also performed by switching of the inverter. Since the present embodiment is an HV vehicle, it has an engine and an engine-driven generator. The battery 10 can be charged by the power generated by the generator, and the motor output shaft can be rotated by the engine. I have. Further, the motor and the generator may be configured as one device as a motor generator.

The HVECU 20 is a battery ECU 1
4 according to the SOC value of the battery 10 supplied from
By controlling motor output, engine output, etc., the battery 1
Control is performed so that the SOC of 0 becomes close to 50%. When overdischarge of the battery cell is detected, discharge from the battery 10 is prohibited.

Here, the battery ECU 14 calculates the charge / discharge current amount of the battery 10 by integrating the output values of the current detector 18 to obtain the integrated SOC. However, in this SOC calculation, the error in the SOC detection increases due to the long-term integration as described above.

Therefore, the battery ECU 14 also estimates the SOC based on the voltage value of the battery 10 detected by the voltage detector 12. This is the S of the battery 10
The relationship between the OC and the electromotive voltage (SOC-electromotive voltage characteristic) is obtained in advance, and the SOC is estimated according to the electromotive voltage at that time.

The battery ECU 14 includes the voltage detector 12
Monitoring the internal resistance of the battery unit based on the detected voltage value of the battery unit, and detecting an abnormality of the battery unit.

FIG. 2 is a schematic flowchart illustrating the operation of the battery management device according to the present invention. Step S50
Processes 70 to 70 are for confirming the operation of the voltage detector corresponding to each battery unit and determining the SOC of each battery unit. The battery ECU 14 sequentially changes the control variable i from 1 to the upper limit N of the number of battery units (here, N = 12),
If the voltage detector corresponding to the i-th battery unit is normal (S60), the SOC of the i-th battery unit is determined from the measured voltage value and the SOC-electromotive force characteristic (S6).
5).

On the other hand, in step S60, for example, when a failure of the voltage detector in charge of the b-th battery unit is detected, for example, the control variable value b is stored in the register.
When the failed voltage detector 12 is present (S75), the battery ECU 14 executes a process S80 as a power storage amount estimating unit. In this process S80, the SO of the b-th battery unit corresponding to the failed voltage detector 12
C is estimated from the SOC obtained in step S65 for the i-th battery unit (i （b) corresponding to the normal voltage detector 12. For example, the estimated SOC of the b-th battery unit can be set to a value equivalent to the SOC of the other battery units, based on the fact that the variation in the SOC of each battery unit is normally small. Specifically, an average value of another SOC can be used. Also, for example, when performing SOC control to keep the maximum value of the SOC of all battery units at or below a predetermined upper limit value and to maintain the minimum value at or above a predetermined lower limit value,
MAX (i ≠ b) which has a predetermined margin for the maximum value MAX (i ≠ b) and the minimum value MIN (i ≠ b) of the SOC other than the b-th battery unit
+ Α, MIN (i ≠ b) −β (where α, β> 0) are used as a maximum value and a minimum value of the SOC of all the battery units including the b-th battery unit, and used for comparison with the upper and lower limits. Is also good.

When there is no failed voltage detector 12 (S75), the SOC control S85 uses only the information on the SOC determined based on the SOC-electromotive force characteristic, and the failed voltage detector 12 If the battery unit exists, control is performed using the information of the estimated SOC so that the SOC is maintained within a predetermined range of each battery unit, for example. That is, according to the present system, appropriate SOC control can be performed even if a failure occurs in the voltage detector 12 corresponding to some of the battery units.

Next, the battery ECU 14 performs processing as battery current suppressing means. That is, the battery ECU 14 detects the temperature at the representative point of the battery 10 based on the output signal of the temperature sensor 16, and controls the normal control value I of the charge / discharge current (battery current) so that the temperature falls within a predetermined range. _C is determined (S90). When all the voltage detectors 12 are normal (S95), the battery ECU 14 determines the control value I
Charge / discharge control is performed using _C. On the other hand, when a failed voltage detector 12 is present (S95), it determines the charge and discharge current control value I _C 'with suppressed than I _C (S100), performs the charge and discharge control by using this.

In this system, the temperature switch used for detecting the abnormality of the battery unit is eliminated in order to reduce the cost and simplify the structure. Therefore, as means for detecting abnormality of the battery unit, the voltage detector 12
Monitoring of the increase in the internal resistance of the battery unit due to the above. Therefore, when the voltage detector 12 fails, it is not possible to detect the occurrence of the abnormality of the battery unit corresponding to the failure.

If an abnormality occurs in the battery unit corresponding to the failed voltage detector 12, Joule heat increases as the internal resistance increases, and the battery may be damaged. One way to avoid this is to turn off the system main relay and not use the battery. However, in this method, the dryness as a hybrid vehicle is reduced. In the present system, when a failure of the voltage detector 12 is detected, drivability is ensured by using a battery while suppressing the charging / discharging current as described above, and the corresponding battery unit , The battery is protected.

Here, the internal resistance at the time of abnormality of the battery unit can be estimated in advance by experiments or the like. Therefore, the internal resistance value is considered when determining the charge / discharge current control value I _C ′. In addition, when determining the control value I _C ′, in addition to this, parameters such as the allowable upper limit value of the temperature of the battery unit and the heat radiation efficiency from the battery unit can be considered.

The above processes S50 to S100 are performed unless the battery management process accompanying the stop of the engine or the like is completed.
Basically, it is repeated (S105).

In the above configuration, the control for suppressing the Joule heat due to the charge / discharge is performed based on the charge / discharge current. Alternatively, the control may be performed using the charge / discharge power. In that case, since the internal resistance of the battery changes with temperature, even if the control value of the charge / discharge power is constant,
The control value of the charging / discharging current can change.

[Second Embodiment] The overall configuration of a system according to the present embodiment is the same as the configuration of the first embodiment shown in FIG.

FIG. 3 is a schematic flowchart illustrating the operation of the battery management device according to the present invention. Voltage detector 12
First, a normal operation in which no failure occurs will be described. Battery EC
If U14 determines that the voltage detector 12 has not failed (S200), the latest integrated SOC is calculated based on the following equation.
Is calculated (S205).

[0039]

SOC (t + Δt) = SOC (t) −I · Δt · η (1) where SOC (t + Δt) is the integrated SO at time t + Δt
C and SOC (t) are the integrated SOC at time t, I is the charge / discharge current, and η is the charge / discharge efficiency. Here, η is basically 1 during discharging, but generally η <1 during charging.
The value of η during charging can change under the influence of SOC.
In general, as the SOC becomes lower, η takes a value closer to 1 and the battery is more likely to be charged, but as the SOC becomes higher, η becomes higher.
And the battery is less likely to be charged. Η is also affected by the temperature of the battery.

The characteristics of η according to the SOC and the temperature can be obtained by experiments and the like. In the calculation of the expression (1) in step S205, a value of the actual charging efficiency according to the SOC and the temperature at that time is basically used as the charging efficiency η.

When the voltage detector 12 is operating normally, it is possible to detect from the IV judgment that the actual SOC has reached the upper limit or the lower limit (S210). When the upper limit determination and the lower limit determination occur, the integrated SOC
Are reset to their upper and lower limits (S21
5).

The SOC control process S220 is performed in step S2.
The charge / discharge control of the battery is performed based on the SOC determined in S05 or S215.

On the other hand, when it is detected that the voltage detector 12 is out of order (S200), the battery ECU 14 performs control to promote charging. For example, battery ECU
14 sets η at the time of charging to a value smaller than the value used in step S205 (S250), and obtains an integrated SOC based on equation (1) (S255). If η at the time of charging is set smaller than the actual value, the SO estimated by the integration
C is evaluated to be smaller, and the battery ECU 14 shifts the weight of the charge / discharge control to the charging side to compensate for it. Thus, the actual SOC of the battery will go to full charge.

Here, since the voltage detector 12 is out of order, the upper limit and the lower limit of the actual SOC cannot be detected by the IV determination. However, it is known that the Ni-MH battery has a property that the temperature rapidly rises when the battery is almost fully charged. Therefore, the temperature sensor 16
Thus, if the temperature change during charging is detected, full charge can be detected. That is, as shown in FIG.
The relationship between the SOC and the temperature change (dT / dt: T is the battery temperature and t is the time) is obtained in advance, and when this change reaches a predetermined value, the SOC can be determined to be 100% (dT / dt). dt determination). When the dT / dt determination occurs (S260), the difference between the integrated SOC and the actual SOC can be eliminated by resetting the integrated SOC to 100% (S265).

In this case, the SOC control processing S220
Battery charge / discharge control is performed based on the SOC determined in step S255 or S265.

In a battery, overdischarging has a more adverse effect such as performance degradation than overcharging. However, in this system, by reducing η from normal time, overdischarging is suppressed and battery protection is reduced. It is planned. Therefore, when a failure of the voltage detector 12 is detected, η may be constantly reduced. After the dT / dt determination occurs, while the accuracy of the integrated SOC can be maintained at a predetermined level, the accuracy of the SOC control is secured by using a normal value as η, and the accuracy of the integrated SOC is below the allowable limit. When the possibility increases, η is sufficiently reduced and step S26 is performed.
5 may be configured to induce the reset process. The timing for starting the reduction of η is, for example, dT /
The determination can be made based on, for example, elapse of a predetermined time from the dt determination or that the integrated SOC has decreased to a predetermined level.

FIG. 5 is a schematic graph showing a time change between the integrated SOC and the actual SOC in the present system.
In the figure, the horizontal axis represents time, and the vertical axis represents SOC. A solid line 300 indicates a change in the value of the integrated SOC, and a dotted line 302 indicates a change in the value of the actual SOC. This figure shows an example in which, after the determination of dT / dt, normal η is used until the integrated SOC decreases to 50%, and thereafter, η is reduced to promote charging. That is, for example, when the dT / dt determination occurs at time t1, the integrated SOC is reset to 100%,
The deviation from the actual SOC is eliminated, the charging efficiency η is set to a normal value, and the SOC control is started. Thereafter, the deviation of the accumulated SOC from the actual SOC may increase with time, but it can be expected that the deviation will not become so large while using the normal η. When the integrated SOC reaches 50% at the time t2, the charging efficiency η is set to a value smaller than the normal time, and the promotion of charging is started. As a result, although the system intends to control the SOC to be maintained at about 50% using the integrated SOC, the actual SO
C deviates from the accumulated SOC and starts to rise. When a dT / dt determination occurs at time t3, the integration S
OC is reset to 100%.

The steps S200 to S265 are basically repeated (S270) as in the first embodiment, unless the battery management processing for stopping the engine or the like is completed.

In the above configuration, the charging efficiency η is set lower than usual in order to intentionally promote charging and cause dT / dt determination. This method has an advantage that the configuration of a program executed on the battery ECU 14 is simple because basic processing is common between when the voltage detector 12 is normal and when it is faulty. However, it is also possible to freely adopt another method as a method of intentionally promoting charging.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a system according to an embodiment of the present invention.

FIG. 2 is a schematic flowchart illustrating a process according to the first embodiment.

FIG. 3 is a schematic flowchart illustrating a process according to a second embodiment.

FIG. 4 is a graph showing a relationship between temperature change (dT / dt) and SOC.

FIG. 5 is a schematic graph showing a time change between an integrated SOC and an actual SOC.

[Explanation of symbols]

10 battery, 12 voltage detector, 14 battery EC
U, 16 temperature sensor, 18 current detector, 20 HV
ECU, 22 load.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G01R 31/36 G01R 31/36 A H01M 10/44 H01M 10/44 Z H02J 7/00 H02J 7/00 B X 7/02 7/02 H 7/10 7/10 B L H F term (reference) 2G016 CA03 CB06 CB12 CB22 CB32 CC01 CC03 CC04 CC13 CC27 5G003 AA07 BA03 CA01 CA14 CB01 CC07 DA07 EA05 EA09 FA06 GC05 5H030 AA08 AS08 BB21 FF22 FF42 FF43 FF44 5H115 PA14 PC06 PG04 PI16 PI24 PI29 PO02 PU08 PU21 PU24 PU25 PU27 PV09 QN03 QN28 SE02 SE03 SE04 SE05 TB01 TI01 TI05 TI06 TI10 TO21 TO23 TR19 TU20 TZ09 TZ14

Claims (5)

[Claims] 1. A voltage sensor for detecting an electromotive voltage of each battery unit of a battery including at least one battery unit, and detecting an abnormality of the battery unit based on the electromotive voltage detected by the voltage sensor. A battery management device, comprising: voltage sensor failure detection means for detecting a failure of the voltage sensor; and when a failure of any of the voltage sensors is detected,
A battery management device comprising: a battery current suppression unit that suppresses a battery current as compared with a normal state. 2. A voltage sensor for detecting an electromotive voltage of each battery unit of a battery including a plurality of battery units is provided, and a storage amount of each of the battery units is determined based on the electromotive voltage detected by the voltage sensor. A battery management device for detecting, wherein a voltage sensor failure detecting means for detecting a failure of the voltage sensor, and when a failure of any of the voltage sensors is detected,
A battery management device, comprising: a power storage amount estimating unit configured to estimate a power storage amount of a battery unit corresponding to a failure voltage sensor based on the power storage amount detected for a remaining non-fault voltage sensor. 3. A battery comprising a plurality of battery units, wherein a voltage sensor for detecting an electromotive voltage is provided for each of the battery units, and abnormality and storage of the battery units are performed based on the electromotive voltage detected by the voltage sensor. A battery management device for detecting an amount, a voltage sensor failure detecting means for detecting a failure of the voltage sensor, and when a failure of any of the voltage sensors is detected,
A battery current suppressing unit that suppresses the battery current more than usual, and when a failure of any one of the voltage sensors is detected,
A battery management device, comprising: a power storage amount estimating unit configured to estimate a power storage amount of a battery unit corresponding to a failure voltage sensor based on the power storage amount detected for a remaining non-fault voltage sensor. 4. The battery management device according to claim 1, wherein the battery current suppression unit suppresses the battery current based on charge / discharge power of the battery. Management device. 5. A battery management device, comprising: means for calculating an integrated charge amount based on an integration of a battery current; and means for correcting the integrated charge amount based on an electromotive voltage of a battery detected by a voltage sensor. A voltage sensor failure detection unit that detects a failure of the voltage sensor; and, when a failure of the voltage sensor is detected, controls a charge amount to be larger than a discharge amount, and fully charges a charge state of the battery. Charge accelerating means for shifting toward the full charge, full charge detecting means for detecting the full charge of the battery based on the battery temperature at the time of charging, and when the full charge is detected by the full charge detecting means, the integrated charge amount And a means for resetting the accumulated amount of stored electricity to a fully charged state.