JP2018159572A - Battery state estimation device - Google Patents

Abstract

At least one embodiment of the present invention is a battery state estimation device that estimates the state of a drive battery of an electric vehicle, and accurately estimates the capacity maintenance rate of the drive battery when charging at home or the like. It is an object of the present invention to provide a battery state estimation device that can be used. In a battery state estimation device for estimating a state of a battery for driving an electric vehicle, an SOC-OCV table 17, a charge rate change amount calculation unit 19, a charge amount calculation unit 21, and a full charge capacity calculation unit 23 are provided. And a capacity maintenance ratio calculator 25, and the capacity maintenance ratio calculated by the capacity maintenance ratio calculator using the SOC-OCV table of the capacity maintenance ratio in the initial state is set as the next capacity maintenance ratio. It is characterized by comprising an iterative calculation unit 27 that repeatedly performs calculation until the capacity maintenance rate converges so that the capacity maintenance rate is further calculated by the capacity maintenance rate calculation unit using the SOC-OCV table of the maintenance rate. . [Selection] Figure 2

Description

  The present disclosure relates to a battery state estimation device, and more particularly, to a state estimation device for a driving battery used in an electric vehicle.

  The battery state indicates a charge rate (SOC: State of Charge), a capacity maintenance rate (SOH: State of Health), and the like, and various proposals have been made as methods for estimating them.

  For example, Patent Literature 1 discloses a battery state estimation method and apparatus, and stores a SOH estimation table in which a SOH value corresponding to various internal resistances for each temperature and SOC is stored in a memory unit; and an SOH estimation request Measuring the temperature, estimating the SOC of the battery, detecting the internal resistance of the battery, and measuring the measured temperature, the estimated SOC of the battery, and the SOH value for the detected internal resistance of the SOH Reading from the estimation table.

Special table 2009-500603 gazette

  In the method disclosed in Patent Document 1 described above, it is necessary to acquire data in advance and acquire the relationship with the SOH value corresponding to the internal resistance value for each temperature and each SOC. In addition, even when the SOH and temperature are the same, the behavior of the change in resistance value differs depending on how the vehicle is used (parallel mode / series mode distribution, etc.). Ideally, it is desirable to comprehensively investigate the assumed vehicle riding conditions and to create a relationship table based on the results, but this is not practical.

  In addition, high-accuracy soundness or capacity maintenance ratio (SOH) is generally measured by discharging from a maintenance shop to charge to full charge. There is a problem that takes about a day and is inconvenient for the user.

  Accordingly, in view of the above technical problem, at least one embodiment of the present invention is a battery state estimation device that estimates the state of a driving battery of an electric vehicle, and maintains the capacity of the driving battery accurately when charging at home or the like. It aims at providing the battery state estimation apparatus which can estimate a rate.

  (1) The present invention has been made to solve the above problems, and a battery state estimation device according to at least one embodiment of the present invention is a battery state estimation device that estimates the state of a battery for driving an electric vehicle. SOC-OCV table storing the relationship between the charging rate and the charging rate for each capacity maintenance rate, and the battery voltage at the start of charging and the battery at the end of charging using the SOC-OCV table when the battery is in a predetermined capacity maintenance rate A charge rate change amount calculating unit that calculates a change amount of a charge rate from the start of charging to the end of charge from the voltage, a charge amount calculating unit that calculates a charge amount between the start of charging and the end of charging, and A full charge capacity calculation unit for calculating a full charge capacity of the battery from a charge rate change amount by the charge rate change amount calculation unit and a charge amount by the charge amount calculation unit; A capacity maintenance rate calculation unit that calculates a capacity maintenance rate from a ratio of the full charge capacity calculated by the full charge capacity calculation unit with respect to a charge capacity, and further, the SOC-OCV table of the capacity maintenance rate in an initial state The capacity maintenance ratio calculated by the capacity maintenance ratio calculator is used as the next capacity maintenance ratio, and the capacity maintenance ratio calculator uses the SOC-OCV table of the next capacity maintenance ratio to further increase the capacity maintenance ratio. It is characterized by comprising an iterative computing unit that repeatedly computes until the capacity maintenance rate converges so as to calculate.

  According to the configuration (1), the capacity maintenance rate calculated by the capacity maintenance rate calculator using the SOC-OCV table of the capacity maintenance rate in the initial state is set as the next capacity maintenance rate, and the SOC of the next capacity maintenance rate is obtained. -Since the capacity maintenance factor is repeatedly calculated by the capacity maintenance factor calculator using the OCV table until the capacity maintenance factor is converged, the capacity maintenance factor is estimated by the convergence operation. By doing so, the capacity maintenance rate of the drive battery can be estimated with high accuracy.

  (2) In some embodiments, the iterative calculation unit calculates a change amount of a charging rate using the SOC-OCV table in the capacity maintenance rate in the initial state, and the capacity based on the change amount. The amount of change in the charging rate is calculated by using the first calculation unit that calculates the first capacity maintenance rate by the maintenance rate calculation unit and the SOC-OCV table of the first capacity maintenance rate calculated by the first calculation unit. And a second operation unit that calculates a second capacity maintenance rate by the capacity maintenance rate calculation unit based on the amount of change, and sequentially calculates the capacity maintenance rate of the battery by repeating the second operation unit. It is characterized by that.

  According to the configuration (2), the capacity maintenance rate can be estimated by the convergence calculation by the first calculation unit and the second calculation unit, and the capacity maintenance rate of the drive battery can be estimated with high accuracy.

  (3) In some embodiments, the timing at the start of charging and at the end of charging is controlled so that the amount of change in the charging rate between the start of charging and the end of charging is greater than or equal to a predetermined value. It is characterized by being.

  According to the configuration (3), it has been found that the estimation accuracy of the capacity maintenance rate can be increased by convergence calculation by appropriately selecting the amount of change in the charging rate. Based on this knowledge, it is possible to increase the estimation accuracy of the capacity maintenance rate by obtaining the amount of change of the charging rate between the start of charging and the end of charging that is equal to or greater than a predetermined value. For example, it has been found that high accuracy is maintained when the amount of change in charging rate (ΔSOC) exceeds 70%.

  (4) In some embodiments, the timing at the start of charging is performed when the battery voltage falls below a predetermined voltage.

  According to the configuration (4), charging is started when the battery voltage drops below a predetermined voltage, so that it is possible to appropriately select the change amount (ΔSOC) of the charging rate.

  (5) In some embodiments, the predetermined voltage is adjusted by increasing and discharging a battery load.

  According to the configuration (5), this can be achieved by increasing the battery load and discharging the battery so as to be less than the predetermined voltage.

  (6) In some embodiments, the capacity maintenance rate in the initial state is in a 100% state.

  According to the configuration (6), since the convergence calculation is always performed from the state where the capacity retention rate in the initial state is 100%, the convergence calculation can be stabilized and ensured.

  According to the configuration (7), the electric vehicle includes a maintenance mode selection switch that selects a maintenance mode for estimating a capacity retention rate of the battery at the time of charging, and the repetition calculation is performed when the maintenance mode is selected. The capacity maintenance rate of the battery is calculated by the unit.

  According to the configuration (7), by selecting the maintenance mode with the maintenance mode selection switch, it is possible to accurately estimate the capacity maintenance rate of the driving battery when charging at home or the like.

  According to at least one embodiment of the present invention, in a battery state estimation device that estimates the state of a drive battery for an electric vehicle, the capacity maintenance rate of the drive battery can be accurately estimated when charging at home or the like. .

It is a whole block diagram of the battery state estimation apparatus which concerns on one Embodiment of this invention. It is a block diagram of the battery capacity estimation part of the battery state estimation apparatus which concerns on one Embodiment of this invention. It is a control flowchart of the battery charging / discharging control part of the battery state estimation apparatus which concerns on one Embodiment of this invention. It is an estimation flowchart of the battery capacity estimation part of the battery state estimation apparatus which concerns on one Embodiment of this invention. It is explanatory drawing which shows the outline | summary of the SOC-OCV table which stored the relationship between the battery voltage (OCV) and charge rate (SOC) of the battery state estimation apparatus which concerns on one Embodiment of this invention for every capacity | capacitance maintenance factor.

  Several embodiments of the present invention will be described below with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in these embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Only.

An overall configuration of a battery state estimation device 1 according to an embodiment of the present invention will be described with reference to FIG.
In this embodiment, the example applied to the drive battery of electric vehicles, such as a plug-in hybrid and an electric vehicle, is shown.
As shown in FIG. 1, the battery state estimation device 1 includes a maintenance mode selection switch 3 and a battery state estimation unit 5 as main components.

  In addition, the electric vehicle includes an air conditioner ECU (Electronic Control Unit) 7 that controls the air conditioning of the vehicle according to a request from the battery state estimation unit 5, a charger ECU (Electronic Control Unit) 9 that controls the in-vehicle charger, and a drive battery A battery ECU (Electronic Control Unit) 11 that performs monitoring and management is provided. In FIG. 1, the battery state estimation device 1 is provided separately from the battery ECU 11, but may be provided in the battery ECU 11.

Further, the state of the battery estimated in the present embodiment refers to a capacity maintenance rate (SOH).
The ratio of the current full charge capacity FCC of the battery to the initial full charge capacity FCC ₀ of the battery, calculated by SOH = FCC / FCC ₀ .

The maintenance mode selection switch 3 is a switch for selecting a maintenance mode provided with a maintenance mode for estimating the capacity retention rate of the battery when the drive battery is charged. Other mode selection switches may be provided independently. It may be set to be selectable as part of.
When the maintenance mode is selected, the capacity maintenance rate of the battery is estimated by the battery state estimation unit 5 described later at the time of charging.

As shown in FIG. 1, the battery state estimation unit 5 mainly includes a battery charge / discharge control unit 13 and a battery capacity estimation unit 15.
When the maintenance mode is selected by the maintenance mode selection switch 3, the battery charge / discharge control unit 13 outputs a control signal to the charger ECU 9 while monitoring the battery voltage, and starts charging and ending the charging of the battery. While controlling the battery voltage and monitoring the battery voltage, the air conditioner ECU 7 is given an operation command to increase the electric load of the battery to control the discharge. In this way, the battery voltage is adjusted by controlling charging / discharging of the battery.

  Further, as shown in FIG. 2, the battery capacity estimation unit 15 mainly includes an SOC-OCV table 17, a charge rate change amount calculation unit 19, a charge amount calculation unit 21, a full charge capacity calculation unit 23, A capacity maintenance rate calculation unit 25 and an iterative calculation unit 27 are provided. Each component will be described next.

  As shown in FIG. 5, the SOC-OCV table 17 has a battery voltage (OCV: Open Circuit Voltage) on the vertical axis, a charge rate (SOC) on the horizontal axis, and a battery for each capacity maintenance rate. The relationship between voltage and charging rate is shown (SOH curve). Therefore, a different characteristic line is shown for each different capacity retention rate. FIG. 5 shows, as an example, a case where the capacity maintenance rate is 100% and the other case of X%.

The charge rate change amount calculation unit 19 uses the SOC-OCV table 17 to charge the battery from the battery voltage at the start of charging and the battery voltage at the end of charging when the battery is in a predetermined capacity maintenance rate state (predetermined SOH curve). A change amount (ΔSOC) of the charging rate from the start to the end of charging is calculated.
In FIG. 5, if the SOC at the start of charging is SOC _L and the SOC at the end is SOC _U , ΔSOC is calculated by equation (1).
ΔSOC = SOC _U −SOC _L (1)

  The OCV uses the battery terminal voltage measurement value as it is, or uses a value estimated by an OCV estimation unit (not shown). When using the terminal voltage measurement value, it is desirable to measure after the terminal voltage has stabilized. When the OCV estimation unit is used, a known technique that takes into account the diffusion phenomenon inside the battery may be used.

  The charge amount calculation unit 21 measures the charge amount from the start of charging to the end of charging. For example, the amount of current (current A) during the charging period (time h) from the start of charging to the end of charging is measured and calculated as the amount of charge ΔQ (Ah).

The full charge capacity calculation unit 23 calculates the full charge capacity (FCC) of the battery from the charge rate change amount (ΔSOC) calculated by the charge rate change amount calculation unit 19 and the charge amount (ΔQ) by the charge amount calculation unit 21. FCC is calculated by the equation (2).
FCC = ΔQ / ΔSOC (2)

The capacity maintenance rate calculation unit 25 calculates a capacity maintenance rate (SOH) from the full charge amount (FCC) calculated by the full charge capacity calculation unit 23 and the full charge capacity (FCC ₀ ) in the initial state. SOH is calculated by the following equation (3).
SOH = FCC / FCC ₀ (3)

  The iterative calculation unit 27 calculates the change rate (ΔSOC) of the charging rate using the SOC-OCV table 17 of the SOH (100%) in the initial state, that is, using the curve of SOH of 100% in FIG. The SOC-OCV table 17 of the next SOH (X%) is defined as the SOH calculated by the charge amount calculation unit 21, the full charge capacity calculation unit 23, and the capacity maintenance rate calculation unit 25 as the next SOH (X%). Using the same procedure, the capacity maintenance rate calculation unit 25 repeatedly calculates the next SOH until the SOH converges (convergence calculation).

More specifically, the iterative calculation unit 27 includes a first calculation unit 29 and a second calculation unit 31.
In the first calculation unit 29, the charge rate change amount calculation unit 19 uses the SOC-OCV table in the initial state of SOH (100%), that is, using the curve of SOH of 100% in FIG. The amount of change (ΔSOC) is calculated, and based on the amount of change, the charge amount calculation unit 21 and the full charge capacity calculation unit 23 calculate the full charge capacity (FCC) of the charging period, and the capacity maintenance rate calculation unit 25 A first capacity maintenance ratio (SOH1 = X%) is calculated based on the full charge capacity (FCC) and the full charge capacity in the initial state (FCC ₀ ).

  The second calculation unit 31 calculates the change amount (ΔSOC ′) of the charging rate using the SOC-OCV table of SOH1 = X% calculated by the first calculation unit 29, and performs the first calculation based on the change amount. The second capacity maintenance ratio (SOH2) is further calculated by the capacity maintenance ratio calculation section 25 in the same manner as the section 29.

The calculation of the second calculation unit 31 is sequentially repeated to sequentially calculate the battery capacity maintenance rate. The calculation is repeated until the deviation between the previous capacity maintenance ratio and the current capacity maintenance ratio becomes less than the allowable convergence error, and the capacity maintenance ratio is estimated.
In addition, you may determine whether it converged by determining the allowable convergence error of the deviation of the full charge amount (FCC) calculated by the full charge capacity calculation unit 23 instead of the capacity maintenance rate and the previous time and the current time.

Next, the estimation flow in the battery state estimation unit 5 will be described with reference to the flowcharts of FIGS.
FIG. 3 mainly shows the control of the battery charge / discharge control unit 13. In addition, the calculation in the battery capacity estimation part 15 is included in part. FIG. 4 is a flowchart of the estimation procedure of the battery capacity estimation unit 15.

  In step S1 of FIG. 3, the charging start flag is turned on upon receiving the charging instruction. In step S2, it is determined whether the maintenance mode is set. That is, it is determined whether the maintenance mode for estimating the capacity maintenance rate of the battery is turned on when the drive battery is charged.

  If the maintenance mode is turned on in step S2, the result is Yes, and the process proceeds to step S3 to measure the voltage. Thereafter, in step S4, it is determined whether the voltage value is less than a threshold voltage (VLth) for starting charging. If the voltage value is not less than the threshold voltage (VLth) for starting charging, the battery is discharged in step S5. An electric discharge operation command is issued to the air conditioner ECU 7 to increase the electric load of the battery and discharge to adjust the voltage.

  If the voltage value is less than the threshold voltage (VLth) for starting charging in step S4, the result is Yes, the voltage data at the start of charging is stored in step S6, and measurement of the amount of charging power is started in step S7. In step S8, charging is started.

  On the other hand, if the maintenance mode is not turned on in step S2, the process proceeds to step S8, and charging is started.

  In step S9, voltage measurement is performed. In step S10, it is determined whether charging is interrupted. That is, it is determined whether the operator interrupted charging for some reason. If it is determined that the charging has been interrupted, the process proceeds to step S12 to end the charging. If charging is not interrupted in step S10, the determination is No and it is determined in step S11 whether the voltage value exceeds the threshold voltage (Vchuth) for interruption. When it does not exceed, it becomes No and returns to step S9 and repeats voltage measurement during charging. If the voltage value exceeds the threshold voltage (Vchuth) in step S11, the answer is Yes, and charging is terminated in step S12.

  Next, in step S13, charging power amount measurement is terminated, charging power amount data is stored in step S14, and voltage data at the end of charging is stored in step S15. In step S16, it is determined whether or not the threshold voltage (Vuth) at the end of charging is exceeded. When it does not exceed, it becomes No and ends.

  In step S16, if the charging end threshold voltage (Vuth) is exceeded, Yes is determined, and in step S17, the full charge capacity (FCC) is calculated. In step S18, it is determined whether the full charge capacity has been successfully calculated. That is, in step S16, if the charging end threshold voltage (Vuth) has been exceeded, it is determined that the capacity calculation has succeeded. If the charging end threshold voltage (Vuth) has not been exceeded, the capacity calculation has failed. In the case of success, the full charge capacity value of the battery is updated in step S19, and in the case of failure, the process ends.

According to the control of the battery charge / discharge control unit 13 described above, the voltage value increases the battery load by the control of the air conditioner so that the charge start is performed when the voltage value reaches below the threshold voltage (VLth) for the charge start. Thus, by adjusting the discharge, it is possible to set the change amount (ΔSOC) of the charging rate to an appropriate amount.
That is, by setting the amount of change in charging rate (ΔSOC) to an appropriate amount, the estimation accuracy of the capacity maintenance rate can be increased by convergence calculation. For example, high accuracy is maintained when ΔSOC exceeds 70%. This ΔSOC is a value calculated using the SOC-OCV table when the capacity maintenance rate is 100%.

Next, the estimation procedure of the battery capacity estimation unit 15 will be described with reference to the flowchart of FIG. Broadly divided into the following 0th step to 4th step.
In the 0th step, before the convergence calculation, the voltages (OCV) VL and Vu before and after charging are read, and the charge amount ΔQ is calculated. Next, the SOH initial value is set to 100% and the FCC value is initialized. Also, a loop counter and a convergence failure flag are initialized.
In the first step, using the SOC-OCV table 17 storing the relationship between the battery voltage (OCV) and the charging rate (SOC) for each capacity maintenance rate, the voltage at the start of charging (VL) and the voltage at the end of charging. From (Vu), a lower limit SOC _L and an upper limit SOC _U are calculated.
In the second step, ΔSOC is calculated using equation (1).
In the third step, FCC (new) is calculated using equation (2).
In the fourth step, when the FCC update difference | FCC-FCC (new) | is larger than the allowable convergence error, the new FCC (new) and the SOH calculated using the new FCC (new) are temporarily updated, and again. The first step to the third step are repeated. When the update difference is smaller than the allowable convergence error, the new FCC (new) repeatedly obtained as successful convergence and the SOH calculated using the FCC are finally updated.

Details of the above 0th step to 4th step will be described with reference to the flowchart of FIG.
In step S21, the voltage VL at the start of charging is read. In step S22, charging current integration is started, and in step S23 charging current integration is terminated. Next, in step S24, the charge amount ΔQ (Ah) is calculated from the integrated value of the current amount (current A) during the charging period (time h) from the start of charging to the end of charging.
In step S25, the SOH initial value is set to 100% and the FCC value is initialized. In step S27, a loop counter and a convergence failure flag are initialized.

  Next, in step S28, it is determined whether the loop counter is less than the upper limit of repetition. The repetition upper limit value is set to 50 times, for example. When the loop counter reaches the upper limit repeatedly, the convergence failure flag 1 is set as a convergence failure and the process is terminated.

In step S28, if the loop counter is less than the upper limit value repeatedly, in step S30, using the SOC-OCV table 17, the voltage at the start of charging (VL) and the voltage at the end of charging (Vu). From the above, the lower limit SOC _L and the upper limit SOC _U are calculated.

Next, in step S31, ΔSOC is calculated using ΔSOC = SOC _U −SOC _L in equation (1). In step S32, it is determined whether ΔSOC exceeds a threshold value. For example, it is determined whether ΔSOC exceeds 70%. If the determination result is No, the process ends. If the determination result is Yes, the process proceeds to step S33, and FCC (new) is calculated using FCC = ΔQ / ΔSOC of Expression (2).

Next, in step S34, it is determined whether the FCC update difference | FCC-FCC (new) | is less than the allowable convergence error. If it is equal to or greater than the allowable convergence error, it becomes No, and in step S35, FCC (new) and SOH calculated using it are temporarily updated, and in step S36, +1 is added to the loop counter, The process from step S28 is repeated again.
The FCC update difference | FCC−FCC (new) | is the difference between the FCC at the previous calculation (previous value) and the FCC at the current calculation (current value) | FCC ( (Previous) -FCC (current) |

  If it is determined in step S34 that the FCC update difference | FCC-FCC (new) | is less than the allowable convergence error, the result is Yes, and the FCC (new) and the SOH calculated using the FCC (new) are determined as the convergence success. Update automatically and exit.

  As shown in FIG. 4, the 0th step is step S21 to step S27, the first step is step S30, the second step is step S31, the third step is step S33, and the fourth step is S34.

As in the estimation flow shown in FIG. 4, the capacity maintenance rate is estimated by repeated convergence calculation, so that the capacity maintenance rate of the driving battery can be estimated with high accuracy.
Further, since the convergence calculation is always performed from the state where the capacity retention rate in the initial state is 100% as shown in step S26, the convergence calculation can be stabilized and ensured.

  According to at least one embodiment of the present invention, the capacity maintenance rate of the driving battery can be accurately estimated when charging at home or the like. Suitable for

DESCRIPTION OF SYMBOLS 1 Battery state estimation apparatus 3 Maintenance mode selection switch 5 Battery state estimation part 7 Air-conditioner ECU
9 Charger ECU
11 Battery ECU
13 battery charge / discharge control unit 15 battery capacity estimation unit 17 SOC-OCV table 19 charge rate change amount calculation unit 21 charge amount calculation unit 23 full charge capacity calculation unit 25 capacity maintenance rate calculation unit 27 repetitive calculation unit 29 first calculation unit 31 2nd operation part

Claims (7)

In a battery state estimation device for estimating the state of a battery for driving an electric vehicle,
An SOC-OCV table storing the relationship between the battery voltage and the charging rate for each capacity maintenance rate;
Using the SOC-OCV table, the amount of change in the charging rate between the start of charging and the end of charging is calculated from the battery voltage at the start of charging and the battery voltage at the end of charging when the battery is in a predetermined capacity maintenance rate. A charge rate change amount calculation unit;
A charge amount calculation unit for calculating a charge amount between the charge start and the charge end;
A full charge capacity calculation unit for calculating a full charge capacity of the battery from a charge rate change amount by the charge rate change amount calculation unit and a charge amount by the charge amount calculation unit;
A capacity maintenance rate calculation unit that calculates a capacity maintenance rate from the ratio of the full charge capacity calculated by the full charge capacity calculation unit to the full charge capacity in an initial state, and
Further, the capacity maintenance rate calculated by the capacity maintenance rate calculator using the SOC-OCV table of the initial capacity maintenance rate is set as the next capacity maintenance rate, and the SOC-OCV table of the next capacity maintenance rate is A battery state estimation device comprising: a repetitive calculation unit that repeatedly uses the capacity maintenance rate calculation unit to calculate the next capacity maintenance rate until the capacity maintenance rate converges. The iterative calculation unit includes:
A first calculation unit that calculates a change amount of the charging rate using the SOC-OCV table in the capacity maintenance rate in the initial state, and calculates a first capacity maintenance rate by the capacity maintenance rate calculation unit based on the change amount. When,
The amount of change in the charging rate is calculated using the SOC-OCV table of the first capacity maintenance rate calculated by the first computing unit, and the second capacity maintenance is calculated by the capacity maintenance rate calculating unit based on the amount of change. A second calculation unit for calculating the rate,
The battery state estimation apparatus according to claim 1, wherein the battery capacity estimation rate is calculated by sequentially repeating the second calculation unit.   2. The timing at the start of charging and at the end of charging is controlled so that the amount of change in the charging rate between the start of charging and the end of charging is greater than a predetermined value. Or the battery state estimation apparatus of 2.   The battery state estimation device according to any one of claims 1 to 3, wherein the timing at the start of charging is performed when the battery voltage drops below a predetermined voltage.   The battery state estimation device according to claim 4, wherein the adjustment of the predetermined voltage is performed by increasing and discharging a battery load.   The battery state estimation device according to claim 1, wherein the capacity maintenance rate in the initial state is in a 100% state.   The electric vehicle includes a maintenance mode selection switch that selects a maintenance mode for estimating a capacity retention rate of the battery during charging. When the maintenance mode is selected, the capacity maintenance rate of the battery is calculated by the repeated calculation unit. The battery state estimation device according to any one of claims 1 to 6, wherein

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