Battery status determination system, battery status determination device, battery status determination method, battery status determination program, and storage medium

Abstract

To provide a battery state determination system, a battery state determination device, a battery state determination method, a battery state determination program, and a storage medium, which enhance the accuracy of computing the internal resistance of a rechargeable battery.SOLUTION: A battery state determination system 8 disclosed herein comprises a controller 14 configured to determine if a rechargeable battery 2 is being charged or discharged. The controller 14 is capable of separately deriving a charging resistance value RC of the rechargeable battery 2 while charging and a discharge resistance value RD while discharging.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The technology disclosed in the present application relates to a battery state determination system, a battery state determination device, a battery state determination method, a battery state determination program, and a storage medium.

Background Art

[0002] Patent Documents 1 to 3 describe a technology for calculating the internal resistance of a battery.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problem to be Solved by the Invention

[0004] However, the value of the internal resistance of a battery differs depending on whether the direction of current flowing through the battery is on the discharge side or the charge side. The technologies described in Patent Documents 1 to 3 do not consider such characteristics of internal resistance, so the calculation accuracy of internal resistance decreases.

[0005] An object of the technology disclosed in the present application is to provide a battery state determination system, a battery state determination device, a battery state determination method, a battery state determination program, and a storage medium that can improve the calculation accuracy of the internal resistance of a rechargeable battery.

Means for Solving the Problem

[0006] According to the first feature, the battery state determination system includes a controller configured to determine whether a rechargeable battery is charging or discharging. The controller is configured to be able to separately calculate the charging resistance value during charging and the discharging resistance value during discharging of the rechargeable battery.

[0007] In the battery state determination system relating to the first feature, the charging resistance value during charging and the discharge resistance value during discharging can be calculated separately. Therefore, compared to the case where the charging resistance value and the discharge resistance value, which are inherently different, are mixed together, the accuracy of calculating the internal resistance of a rechargeable battery can be improved.

[0008] According to the second feature, in the battery state determination system relating to the first feature, the controller is configured to acquire the current value of the rechargeable battery. The controller is configured to determine whether the rechargeable battery is charging or discharging based on the sign of the current value.

[0009] In the battery state determination system relating to the second feature, it is determined whether a rechargeable battery is charging or discharging based on the sign of the current value, thus enabling accurate determination of charging and discharging.

[0010] According to the third feature, in the battery state determination system relating to the second feature, the controller is configured to acquire the current value as the charging current value when the sign of the current value is either positive or negative. The controller is configured to acquire the current value as the discharge current value when the sign of the current value is either positive or negative. The controller is configured to calculate the charging resistance value based on the charging current value. The controller is configured to calculate the discharge resistance value based on the discharge current value.

[0011] In the battery state determination system related to the third feature, by separately acquiring the charging current value and the discharging current value, the charging resistance value and the discharging resistance value can be calculated with high accuracy using the charging current value and the discharging current value, respectively.

[0012] According to the fourth feature, in the battery state determination system relating to the third feature, the controller is configured to acquire the voltage value of a rechargeable battery as the charging voltage value when the sign of the current value is either positive or negative. The controller is configured to acquire the voltage value as the discharge voltage value when the sign of the current value is the other of positive or negative. The controller is configured to calculate the charging resistance value based on the charging current value and the charging voltage value. The controller is configured to calculate the discharge resistance value based on the discharge current value and the discharge voltage value.

[0013] In the battery state determination system related to the fourth feature, the charging voltage value and the discharging voltage value are acquired separately, thereby improving the accuracy of calculating the charging resistance value and the discharging resistance value, respectively, using the charging voltage value and the discharging voltage value.

[0014] According to the fifth feature, in the battery state determination system relating to the fourth feature, the controller is configured to periodically acquire the charging current value and the charging voltage value. The controller is configured to calculate the charging current difference by subtracting the previous charging current value from the latest charging current value. The controller is configured to calculate the charging voltage difference by subtracting the previous charging voltage value from the latest charging voltage value. The controller is configured to calculate the charging resistance value based on the charging current difference and the charging voltage difference.

[0015] In the battery state determination system related to the fifth feature, the accuracy of calculating the charging resistance value can be further improved by using the difference in charging current and the difference in charging voltage.

[0016] According to the sixth feature, in the battery state determination system relating to the fifth feature, the controller is configured to calculate a first charging resistance value based on the charging current difference and the charging voltage difference when the sign of the charging current difference is either positive or negative. The controller is configured to calculate a second charging resistance value based on the charging current difference and the charging voltage difference when the sign of the charging current difference is the other of positive or negative.

[0017] In the battery state determination system relating to the sixth feature, the first charging resistance value and the second charging resistance value are calculated separately according to the sign of the charging current difference, thereby further improving the accuracy of the charging resistance value calculation.

[0018] According to the seventh feature, in the battery state determination system relating to the fifth or sixth feature, when the charging resistance value is RC, the charging current difference is ΔAC, and the charging voltage difference is ΔVC, RC = ∫(ΔVC / ΔAC)dt, and, RC=∫(ΔAC×ΔVC)dt / ∫(ΔAC×ΔAC)dt It is configured to calculate the charging resistance value based on one of the following.

[0019] The battery state determination system related to the seventh feature can further improve the accuracy of calculating the charging resistance value.

[0020] According to the eighth feature, in a battery state determination system relating to any one of the first to sixth features, the controller is configured to periodically calculate the charging resistance value. The controller is configured to calculate the charging resistance value as one of the weighted average, moving average, and arithmetic mean of multiple periodically calculated charging resistance values.

[0021] The battery state determination system related to the eighth feature can further improve the accuracy of calculating the charging resistance value.

[0022] According to a ninth feature, in the battery state determination system according to any one of the fourth to seventh features, the controller is configured to periodically acquire a discharge current value and a discharge voltage value. The controller is configured to calculate a discharge current difference by subtracting a previous discharge current value from a latest discharge current value among the discharge current values. The controller is configured to calculate a discharge voltage difference by subtracting a previous discharge voltage value from a latest discharge voltage value among the discharge voltage values. The controller is configured to calculate a discharge resistance value based on the discharge current difference and the discharge voltage difference.

[0023] In the battery state determination system according to the ninth feature, the calculation accuracy of the discharge resistance value can be further improved by using the discharge current difference and the discharge voltage difference.

[0024] According to a tenth feature, in the battery state determination system according to the ninth feature, the controller is configured to calculate a first discharge resistance value based on the discharge current difference and the discharge voltage difference when the sign of the discharge current difference is one of positive and negative. The controller is configured to calculate a second discharge resistance value based on the discharge current difference and the discharge voltage difference when the sign of the discharge current difference is the other of positive and negative.

[0025] In the battery state determination system according to the tenth feature, the first discharge resistance value and the second discharge resistance value are calculated separately according to the sign of the discharge current difference, so the calculation accuracy of the discharge resistance value can be further improved.

[0026] According to an eleventh feature, in the battery state determination system according to the ninth or tenth feature, when the discharge resistance value is RD, the discharge current difference is ΔAD, and the discharge voltage difference is ΔVD, the controller is configured to: RD=∫(ΔVD / ΔAD)dt, and RD=∫(ΔAD×ΔVD)dt / ∫(ΔAD×ΔAD)dt configured to calculate the discharge resistance value based on one of the above.

[0027] The battery state determination system related to the eleventh feature can further improve the accuracy of calculating the discharge resistance value.

[0028] According to the twelfth feature, in a battery state determination system relating to any one of the first to tenth features, the controller is configured to periodically calculate the discharge resistance value. The controller is configured to calculate the discharge resistance value as one of the weighted average, moving average, and arithmetic mean of multiple periodically calculated discharge resistance values.

[0029] The battery state determination system related to the 12th feature can further improve the accuracy of calculating the charging resistance value.

[0030] According to the 13th feature, in a battery state determination system relating to any one of the first to 12 features, the controller is configured to acquire at least one of the rechargeable battery temperature and estimated charge level. The controller is configured to correct at least one of the charging resistance value and discharge resistance value based on at least one of the temperature and estimated charge level.

[0031] The battery state determination system relating to the 13th feature can further improve the calculation accuracy of at least one of the charging resistance value and the discharge resistance value depending on the state of the rechargeable battery.

[0032] According to the 14th feature, a battery state determination system relating to any one of the 1st to 13th features further comprises a current sensor that is electrically connected to a controller and configured to measure the current value of a rechargeable battery.

[0033] The battery status determination system related to the 14th feature allows for the acquisition of current values ​​measured by a current sensor relatively quickly.

[0034] According to the 15th feature, a battery state determination system relating to any one of the 1st to 14th features further comprises a voltage sensor that is electrically connected to a controller and configured to measure the voltage value of a rechargeable battery.

[0035] The battery status determination system related to the 15th feature can acquire voltage values ​​measured by a voltage sensor relatively quickly.

[0036] According to the 16th feature, the battery state determination device includes a controller configured to determine whether a rechargeable battery is being charged or discharged. The controller is configured to be able to separately calculate the charging resistance value during charging and the discharge resistance value during discharging of the rechargeable battery.

[0037] In the battery state determination device relating to the 16th feature, the charging resistance value during charging and the discharge resistance value during discharging can be calculated separately. Therefore, compared to the case where the charging resistance value and the discharge resistance value, which are inherently different, are mixed together, the accuracy of calculating the internal resistance of a rechargeable battery can be improved.

[0038] According to the 17th feature, the battery status determination method includes the controller determining whether a rechargeable battery is being charged or discharged, and the controller separately calculating the charging resistance value during charging and the discharge resistance value during discharge of the rechargeable battery.

[0039] In the battery state determination method related to the 17th feature, the charging resistance value during charging and the discharge resistance value during discharging are calculated separately. Therefore, compared to the case where the charging resistance value and the discharge resistance value, which are inherently different, are mixed together, the accuracy of calculating the internal resistance of a rechargeable battery can be improved.

[0040] According to the 18th feature, the battery status determination program causes the computer to execute the battery status determination method related to the 17th feature.

[0041] The battery status determination program related to the 18th feature can improve the accuracy of calculating the internal resistance of rechargeable batteries.

[0042] According to the 19th feature, a computer-readable storage medium stores a battery status determination program related to the 18th feature.

[0043] The storage medium relating to the 19th feature can improve the accuracy of calculating the internal resistance of a rechargeable battery. [Brief explanation of the drawing]

[0044] [Figure 1] Figure 1 is a schematic block diagram of the battery state determination system according to the first embodiment. [Figure 2] Figure 2 is a graph showing the relationship between the current value and resistance value of a rechargeable battery. [Figure 3] Figure 3 is a schematic block diagram showing the information exchange in the battery status determination system shown in Figure 1. [Figure 4] Figure 4 is a flowchart showing the battery status determination method performed in the battery status determination system shown in Figure 1. [Figure 5] Figure 5 is a schematic block diagram of the battery state determination system according to the second embodiment. [Figure 6] Figure 6 is a graph showing the relationship between the current value and resistance value of a rechargeable battery. [Figure 7] Figure 7 is a flowchart showing the battery status determination method performed in the battery status determination system shown in Figure 5. [Figure 8] Figure 8 is a schematic block diagram showing the information exchange in the battery state determination system according to the first modified example. [Figure 9] Figure 9 is a flowchart showing the battery status determination method performed in the battery status determination system shown in Figure 8. [Figure 10]Figure 10 is a schematic block diagram showing the information exchange in the battery status determination system according to the second modified example. [Figure 11] Figure 11 is a flowchart showing the battery status determination method performed in the battery status determination system shown in Figure 10. [Modes for carrying out the invention]

[0045] The embodiments will be described below with reference to the drawings. In the drawings, the same reference numerals indicate corresponding or identical components.

[0046] First Embodiment As shown in Figure 1, the rechargeable battery 2 is electrically connected to the load 4. The rechargeable battery 2 supplies electricity to the load 4. The rechargeable battery 2 includes, for example, secondary batteries such as lead-acid batteries, lithium-ion batteries, and nickel-metal hydride batteries. Therefore, the rechargeable battery 2 may also be referred to as the secondary battery 2.

[0047] Load 4 is powered by electricity supplied from rechargeable battery 2. Load 4 includes at least one electrical device. If rechargeable battery 2 is installed in a vehicle, examples of electrical devices include an electronic control unit (ECU), lights, heaters, audio equipment, sensors, and cameras.

[0048] Examples of vehicles include automobiles. Examples of automobiles include automobiles equipped with an engine (internal combustion engine) as a power source, hybrid vehicles equipped with an engine and a vehicle drive motor as power sources, and electric vehicles or fuel cell vehicles equipped with a vehicle drive motor as a power source. Therefore, for example, the rechargeable battery 2 may be used for vehicle propulsion, or a vehicle drive battery other than the rechargeable battery 2 may be installed in the vehicle. The vehicles are not limited to the above-mentioned vehicles. In addition, the rechargeable battery 2 may be used for purposes other than vehicles.

[0049] The rechargeable battery 2 is electrically connected to the charging circuit 6. The charging circuit 6 supplies electricity to the rechargeable battery 2 and charges it. When the rechargeable battery 2 is mounted in a vehicle, for example, the charging circuit 6 includes power generation devices such as an alternator and a vehicle drive motor.

[0050] Incidentally, in order to understand the state of rechargeable battery 2, it is sometimes necessary to calculate its internal resistance. Using the internal resistance, it is possible to determine the state of rechargeable battery 2 (for example, degradation detection, full charge detection, and SOF (State of Function) detection). However, the value of the internal resistance differs depending on whether the current flows in the discharge or charging direction.

[0051] Therefore, the battery state determination system 8 is configured to be able to calculate the resistance value of the rechargeable battery 2 separately during charging and discharging. Here, "configured to be able to calculate separately" includes not only "configured to always calculate separately" but also "configured to calculate separately by switching control, etc. (including being configured not to calculate separately by control)." The battery state determination system 8 includes, for example, a battery state determination device 10, an external device 30, and an external device 40. The battery state determination device 10 is electrically connected to the rechargeable battery 2. The battery state determination device 10 operates on electricity supplied from the rechargeable battery 2.

[0052] The battery state determination system 8 is configured to calculate the resistance value of the rechargeable battery 2 separately during charging and discharging. The battery state determination device 10 includes a controller 14. That is, the battery state determination system 8 includes a controller 14. In this embodiment, the controller 14 constitutes, for example, an ECU (Electronic Control Unit). The controller 14 is electrically connected to the rechargeable battery 2. The controller 14 includes, for example, a processor 14P, memory 14M, circuit board 14C, and bus 14B.

[0053] The processor 14P includes, for example, a CPU (Central Processing Unit) and / or an MPU (Micro Processing Unit). The memory 14M includes, for example, volatile and / or non-volatile memory. Examples of volatile memory include RAM (Random Access Memory) and / or DRAM (Dynamic Random Access Memory). Examples of non-volatile memory include ROM (Read Only Memory) and EEPROM (Electrically Erasable Programmable ROM). The memory 14M may also be referred to as a computer-readable storage medium. The processor 14P and the memory 14M are electrically mounted on a circuit board 14C. The processor 14P and the memory 14M are electrically connected to each other via the circuit board 14C. The processor 14P may also be referred to as a hardware processor 14P. The memory 14M may also be referred to as hardware memory 14M.

[0054] The controller 14 is programmed to implement the control algorithms for the battery state determination system 8 and the battery state determination device 10. The memory 14M of the controller 14 stores software, such as programs for implementing the control algorithms for the battery state determination system 8 and the battery state determination device 10. The processor 14P implements the control algorithms for the battery state determination system 8 and the battery state determination device 10 by reading and executing the programs stored in the memory 14M.

[0055] The configuration of the controller 14 is not limited to a processor 14P, memory 14M, circuit board 14C, and bus 14B. The configuration of the controller 14 can be realized by hardware alone or by a combination of hardware and software. Furthermore, the processor 14P and memory 14M may be configured as a single chip, such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array). Note that the controller 14 may also be referred to as a controller circuit 14, controller circuitry 14, circuit 14, and / or circuitry 14.

[0056] The controller 14 is electrically connected to the rechargeable battery 2. The controller 14 operates on electricity supplied from the rechargeable battery 2 to the power supply circuit 14S. The controller 14 includes a power supply circuit 14S that is electrically connected to the rechargeable battery 2. The power supply circuit 14S converts, for example, the voltage supplied from the rechargeable battery 2 (e.g., 12V) to a predetermined voltage (e.g., 3.3V or 5V) as needed. The power supply circuit 14S is electrically connected to the processor 14P and the memory 14M via the circuit board 14C and the bus 14B.

[0057] The battery state determination device 10 further includes a current sensor 16. That is, the battery state determination system 8 further includes a current sensor 16. The current sensor 16 is electrically connected to the controller 14 and configured to measure the current value of the rechargeable battery 2. The controller 14 is configured to acquire the current value of the rechargeable battery 2. The current sensor 16 is placed between the rechargeable battery 2 and the load 4, and between the rechargeable battery 2 and the charging circuit 6. The current sensor 16 is configured to measure the current value of the discharge current flowing from the rechargeable battery 2 to the load 4, and to measure the current value of the charging current flowing from the charging circuit 6 to the rechargeable battery 2. The controller 14 acquires the current value measured by the current sensor 16 at predetermined intervals and stores the acquired measured current value in the memory 14M.

[0058] The controller 14 is configured to determine whether the rechargeable battery 2 is charging or discharging. The controller 14 is configured to determine whether the rechargeable battery 2 is charging or discharging based on the sign of the current value. The controller 14 is configured to determine whether the rechargeable battery 2 is charging or discharging based on the sign of the current value measured by the current sensor 16.

[0059] The controller 14 is configured to acquire the current value as the charging current value AC when the sign of the current value is either positive or negative. The controller 14 is configured to acquire the current value as the charging current value AC when the sign of the current value measured by the current sensor 16 is either positive or negative. For example, the controller 14 is configured to acquire the current value as the charging current value AC when the sign of the current value measured by the current sensor 16 is positive. However, the controller 14 may also be configured to acquire the current value as the charging current value AC when the sign of the current value is negative.

[0060] The controller 14 is configured to acquire the current value as the discharge current value AD when the sign of the current value is either positive or negative. The controller 14 is configured to acquire the current value as the discharge current value AD when the sign of the current value measured by the current sensor 16 is either positive or negative. For example, the controller 14 is configured to acquire the current value as the discharge current value AD when the sign of the current value measured by the current sensor 16 is negative. However, the controller 14 may also be configured to acquire the current value as the discharge current value AD when the sign of the current value measured by the current sensor 16 is positive.

[0061] The battery state determination device 10 further includes a voltage sensor 18. That is, the battery state determination system 8 further includes a voltage sensor 18. The voltage sensor 18 is electrically connected to the controller 14 and configured to measure the voltage value of the rechargeable battery 2. The controller 14 acquires the measured voltage value of the voltage sensor 18 at predetermined intervals and stores the acquired measured voltage value in the memory 14M.

[0062] The controller 14 is configured to acquire the voltage value of the rechargeable battery 2 as the charging voltage value VC when the sign of the current value is either positive or negative. The controller 14 is configured to acquire the voltage value as the discharge voltage value VD when the sign of the current value is the other of positive or negative.

[0063] The controller 14 is configured to acquire the voltage value VC as the charging voltage value when the sign of the voltage value measured by the voltage sensor 18 is either positive or negative. The controller 14 is configured to acquire the voltage value VD as the discharge voltage value when the sign of the voltage value measured by the voltage sensor 18 is either positive or negative. For example, the controller 14 is configured to acquire the voltage value VC as the charging voltage value when the sign of the voltage value measured by the voltage sensor 18 is positive. The controller 14 is configured to acquire the voltage value VD as the discharge voltage value when the sign of the voltage value measured by the voltage sensor 18 is negative. However, the controller 14 may be configured to acquire the voltage value VC as the charging voltage value when the sign of the voltage value is negative. The controller 14 may be configured to acquire the voltage value VD as the discharge voltage value when the sign of the voltage value is positive.

[0064] As shown in Figure 2, the controller 14 is configured to separately calculate the charging resistance value RC during charging and the discharge resistance value RD during discharging of the rechargeable battery 2. The controller 14 is configured to calculate the charging resistance value RC based on the charging current value AC. The controller 14 is configured to calculate the discharge resistance value RD based on the discharge current value AD.

[0065] The controller 14 is configured to calculate the charging resistance value RC based on the charging current value AC and the charging voltage value VC. The controller 14 is configured to calculate the discharge resistance value RD based on the discharge current value AD and the discharge voltage value VD.

[0066] As shown in Figure 1, the controller 14 is configured to periodically acquire the charging current value AC and the charging voltage value VC. The controller 14 stores a predetermined number of periodically acquired charging current values ​​AC in memory 14M, starting from the latest charging current value AC1. The controller 14 also stores a predetermined number of periodically acquired charging voltage values ​​VC in memory 14M, starting from the latest charging voltage value VC1.

[0067] The controller 14 is configured to calculate the charging current difference by subtracting the previous charging current value AC2 from the latest charging current value AC1 of the charging current value AC. The controller 14 is configured to calculate the charging current difference ΔAC based on the latest charging current value AC1, the previous charging current value AC, and the following equation (1).

[0068] ΔAC = AC1 - AC2 ... (1) The controller 14 is configured to calculate the charging voltage difference by subtracting the previous charging voltage value VC2 from the latest charging voltage value VC1 of the charging voltage value VC. The controller 14 is configured to calculate the charging voltage difference ΔVC based on the latest charging voltage value VC1, the previous charging voltage value VC2, and the following equation (2).

[0069] ΔVC = VC1 - VC2 ... (2) The controller 14 is configured to calculate the charging resistance value RC based on the charging current difference ΔAC and the charging voltage difference ΔVC. For example, based on the following equation (3), the controller 14 is configured to calculate the charging resistance value RC by dividing the charging voltage difference ΔVC by the charging current difference ΔAC.

[0070] RC = ΔVC / ΔAC ... (3) The controller 14 is configured to periodically calculate the charging resistance value RC. For example, the controller 14 stores the charging resistance value RC calculated in equation (3) as the current charging resistance value RC1 in memory 14M. In other words, equation (3) above can also be expressed as follows.

[0071] RC1 = ΔVC / ΔAC ... (3A) The controller 14 is configured to calculate the charging resistance value RC as one of the weighted average, moving average, and arithmetic mean of multiple periodically calculated charging resistance values ​​RC. The controller 14 is configured to calculate the charging resistance value RC as the weighted average of the current charging resistance value RC1 and the previous charging resistance value RC2 based on the following equation (4) (the weighting coefficient KC is a number from 0 to 1).

[0072] RC=(1-KC)×RC2+KC×RC1 (4) The controller 14 stores the charging resistance value RC calculated by equation (4) in memory 14M. When the controller 14 calculates a new charging resistance value RC using equation (4), it stores the previously calculated charging resistance value RC using equation (4) as the previous charging resistance value RC2 in memory 14M. The controller 14 may also be configured to calculate the charging resistance value RC as the moving average or arithmetic mean of multiple periodically calculated charging resistance values ​​RC.

[0073] The controller 14 is configured to periodically acquire the discharge current value AD and the discharge voltage value VD. The controller 14 stores a predetermined number of periodically acquired discharge current values ​​AD in memory 14M, starting from the latest discharge current value AD1. The controller 14 also stores a predetermined number of periodically acquired discharge voltage values ​​VD in memory 14M, starting from the latest discharge voltage value VD1.

[0074] The controller 14 is configured to calculate the discharge current difference ΔAD by subtracting the previous discharge current value AD2 from the latest discharge current value AD1 of the discharge current value AD. When the latest discharge current value is AD1, the previous discharge current value is AD2, and the discharge current difference is ΔAD, the controller 14 is configured to calculate the discharge current difference ΔAD based on the following equation (5).

[0075] ΔAD = AD1 - AD2 ... (5) The controller 14 is configured to calculate the discharge voltage difference ΔVD by subtracting the previous discharge voltage value VD2 from the latest discharge voltage value VD1. When the latest discharge voltage value is VD1, the previous discharge voltage value is VD2, and the discharge voltage difference is ΔVD, the controller 14 is configured to calculate the discharge voltage difference ΔVD based on the following equation (6).

[0076] ΔVD = VD1 - VD2 ... (6) The controller 14 is configured to calculate the discharge resistance value RD based on the discharge current difference ΔAD and the discharge voltage difference ΔVD. For example, based on the following equation (7), the controller 14 is configured to calculate the discharge resistance value RD by dividing the discharge voltage difference ΔVD by the discharge current difference ΔAD.

[0077] RD = ΔVD / ΔAD ... (7) The controller 14 is configured to periodically calculate the discharge resistance value RD. For example, the controller 14 stores the discharge resistance value RD calculated in equation (7) as the current discharge resistance value RD1 in memory 14M. In other words, equation (7) above can also be expressed as follows.

[0078] RD1 = ΔVD / ΔAD ... (7A) The controller 14 is configured to calculate the discharge resistance value RD as one of the weighted average, moving average, and arithmetic mean of multiple periodically calculated discharge resistance values ​​RD. The controller 14 is configured to calculate the discharge resistance value RD as the weighted average of the current discharge resistance value RD1 and the previous discharge resistance value RD2 based on the following equation (8) (the weighting coefficient KD is a number from 0 to 1).

[0079] RD=(1-KD)×RD2+KD×RD1 ···(8) The controller 14 stores the discharge resistance value RD calculated by equation (8) in memory 14M. When the controller 14 calculates a new discharge resistance value RD using equation (8), it stores the previously calculated discharge resistance value RD using equation (8) as the previous discharge resistance value RD2 in memory 14M. The controller 14 may also be configured to calculate the discharge resistance value RD as the moving average or arithmetic mean of multiple periodically calculated discharge resistance values ​​RD.

[0080] The controller 14 is configured to acquire at least one of the temperature and estimated charge level of the rechargeable battery 2. The battery state determination device 10 includes a temperature sensor 19. The temperature sensor 19 is electrically connected to the controller 14 and is configured to measure the temperature of the rechargeable battery 2. The controller 14 is configured to periodically acquire the temperature measured by the temperature sensor 19 and store the measured temperature in the memory 14M.

[0081] The controller 14 is configured to calculate the estimated state of charge (SOC) of the rechargeable battery 2 based on at least one of the measured current value of the current sensor 16 and the measured voltage value of the voltage sensor 18. The controller 14 is configured to calculate the estimated state of charge of the rechargeable battery 2 based on methods such as the OCV method and the current integration method.

[0082] The controller 14 is configured to correct at least one of the charging resistance value RC and the discharge resistance value RD based on temperature and at least one of the estimated charge level. For example, the controller 14 stores a first relational expression in memory 14M that shows the relationship between temperature and the charging resistance value RC. The controller 14 is configured to correct the charging resistance value RC based on the first relational expression and the measured temperature. The controller 14 also stores a second relational expression in memory 14M that shows the relationship between the estimated charge level and the charging resistance value RC. The controller 14 is configured to correct the charging resistance value RC based on the second relational expression and the estimated charge level. However, at least one of the correction of the charging resistance value RC by temperature and the correction of the charging resistance value RC by the estimated charge level may be omitted from the control of the controller 14.

[0083] Similarly, the controller 14 stores a third relational expression in memory 14M that shows the relationship between temperature and discharge resistance value RD. The controller 14 is configured to correct the discharge resistance value RD based on the third relational expression and the measured temperature. The controller 14 also stores a fourth relational expression in memory 14M that shows the relationship between the estimated charge rate and the discharge resistance value RD. The controller 14 is configured to correct the discharge resistance value RD based on the fourth relational expression and the estimated charge rate. However, at least one of the correction of discharge resistance value RD by temperature and the correction of discharge resistance value RD by discharge rate may be omitted from the control of the controller 14.

[0084] The controller 14 is configured to determine the state of the rechargeable battery 2 based on at least one of the charging resistance value RC and the discharging resistance value RD. As the degradation of the rechargeable battery 2 progresses, the internal resistance of the rechargeable battery 2 increases.

[0085] For example, the controller 14 is configured to determine whether the rechargeable battery 2 needs to be replaced by comparing the charging resistance value RC with the charging resistance threshold TC. Specifically, the controller 14 is configured to determine that the rechargeable battery 2 needs to be replaced if the charging resistance value RC is greater than or equal to the charging resistance threshold TC. The controller 14 is configured to determine that the rechargeable battery 2 does not need to be replaced if the charging resistance value RC is less than the charging resistance threshold TC. The controller 14 stores the charging resistance threshold TC in memory 14M. The charging resistance threshold TC is set to a value suitable for determination based on the charging resistance value RC. Note that the charging resistance value RC and the charging resistance threshold TC may be used for other control purposes. The controller 14 may also be configured not to use the charging resistance value RC and the charging resistance threshold TC to determine whether the rechargeable battery 2 needs to be replaced.

[0086] Similarly, the controller 14 is configured to determine whether the rechargeable battery 2 needs to be replaced by comparing the discharge resistance value RD with the discharge resistance threshold TD. Specifically, the controller 14 is configured to determine that the rechargeable battery 2 needs to be replaced if the discharge resistance value RD is greater than or equal to the discharge resistance threshold TD. The controller 14 is configured to determine that the rechargeable battery 2 does not need to be replaced if the discharge resistance value RD is less than the discharge resistance threshold TD. The controller 14 stores the discharge resistance threshold TD in memory 14M. The discharge resistance threshold TD is set to a value suitable for determination based on the discharge resistance value RD.

[0087] As shown in Figure 1, the battery state determination device 10 further includes an interface 20 electrically connected to the controller 14. The interface 20 is configured to receive input information and / or transmit battery state determination results to external devices 30 and / or 40. The battery state determination results indicate at least one of the following: a charging resistance value RC, a discharging resistance value RD, a battery state determination result based on the charging resistance value RC, and a battery state determination result based on the discharging resistance value RD.

[0088] Interface 20 is electrically connected to the processor 14P and memory 14M via the circuit board 14C and bus 14B. Interface 20 operates on electricity supplied from the controller 14. Interface 20 includes a user interface 22 and a communication unit 24.

[0089] The user interface 22 is electrically connected to the controller 14. The user interface 22 is electrically connected to the processor 14P and memory 14M via the circuit board 14C and bus 14B. The user interface 22 is configured to receive input information from the user. The controller 14 stores the input information received from the user interface 22 in memory 14M. An example of the user interface 22 is an operation panel such as a touch panel.

[0090] The communication unit 24 is electrically connected to the controller 14. The communication unit 24 is electrically connected to the processor 14P and the memory 14M via the circuit board 14C and the bus 14B. The communication unit 24 is configured to receive input information from external devices 30 and / or 40. The controller 14 stores the input information received by the communication unit 24 in the memory 14M. The communication unit 24 is also configured to transmit battery status determination results to external devices 30 and / or 40.

[0091] The communication unit 24 includes a wireless communication circuit. The wireless communication circuit is electrically connected to the controller 14 and can connect wirelessly to, for example, the internet. The wireless communication circuit is configured to transmit battery status determination results to an external device 30 via the internet. When a rechargeable battery 2 is installed in a vehicle, the communication unit 24 includes, for example, a wireless communication circuit and a gateway ECU.

[0092] A wireless communication circuit includes, for example, an antenna, a wireless transmitting circuit, and a wireless receiving circuit. The antenna is electrically connected to the wireless transmitting circuit and the wireless receiving circuit. The wireless transmitting circuit is configured to transmit a signal wirelessly via the antenna. The wireless receiving circuit is configured to receive a signal wirelessly via the antenna. The wireless transmitting circuit is configured to encrypt the signal using a predetermined protocol. The wireless receiving circuit is configured to decrypt the wireless signal using a predetermined protocol.

[0093] As shown in Figure 1, the external device 30 is a device that performs various information processing and may also be referred to as a server 30. The external device 30 can, for example, constitute part of a data center or cloud and be connected to the internet. The external device 30 comprises a controller 32, an interface 33, and a display 34. The interface 33 and the display 34 are electrically connected to the controller 32. The display 34 is electrically connected to the controller 32 and configured to display information. The controller 32 is configured to control the display 34 to display information.

[0094] The controller 32 includes, for example, a processor 32P, memory 32M, a circuit board 32C, and a bus 32B. The processor 32P includes, for example, a CPU and / or MPU. The memory 32M includes, for example, volatile and / or non-volatile memory. Examples of volatile memory include RAM and / or DRAM. Examples of non-volatile memory include ROM and EEPROM. The memory 32M may also be referred to as a computer-readable storage medium. The processor 32P and the memory 32M are electrically mounted on the circuit board 32C. The processor 32P and the memory 32M are electrically connected to each other via the circuit board 32C. The processor 32P may also be referred to as a hardware processor 32P. The memory 32M may also be referred to as hardware memory 32M.

[0095] The controller 32 is programmed to implement the control algorithm for the external device 30. The controller 32's memory 32M stores software, such as a program for implementing the control algorithm for the external device 30. The processor 32P implements the control algorithm for the external device 30 by reading and executing the program stored in memory 32M.

[0096] The configuration of the controller 32 is not limited to a processor 32P, memory 32M, circuit board 32C, and bus 32B. The configuration of the controller 32 can be realized by hardware alone or by a combination of hardware and software. Furthermore, the processor 32P and memory 32M may be configured as a single chip, such as an ASIC or FPGA. Note that the controller 32 may also be referred to as a controller circuit 32, controller circuitry 32, circuit 32, and / or circuitry 32.

[0097] Interface 33 is electrically connected to the processor 32P and memory 32M via the circuit board 32C and bus 32B. Interface 33 includes a user interface 35 and a communication unit 36.

[0098] The user interface 35 is electrically connected to the controller 32. The user interface 35 is electrically connected to the processor 32P and memory 32M via the circuit board 32C and bus 32B. The user interface 35 is used when the user operates the external device 30. Examples of the user interface 35 include a keyboard, mouse, and touch panel.

[0099] The communication unit 36 ​​is electrically connected to the controller 32. The communication unit 36 ​​is electrically connected to the processor 32P and memory 32M via the circuit board 32C and bus 32B. The communication unit 36 ​​is configured to communicate with the battery status determination device 10 and the external device 40.

[0100] The communication unit 36 ​​includes, for example, a wired communication circuit. The wired communication circuit is electrically connected to the controller 32 and can connect to the internet via a wire, for example. The wired communication circuit is configured to communicate with the battery status determination device 10 and the external device 40 via the internet. The communication unit 36 ​​may also include a wireless communication circuit.

[0101] As shown in Figure 3, the communication unit 36 ​​is configured to receive the battery status determination result BR from the battery status determination device 10. The communication unit 36 ​​is configured to transmit the battery status determination result BR received from the battery status determination device 10 to the external device 40. The communication unit 36 ​​is configured to receive input information from the external device 40. The communication unit 36 ​​is configured to transmit at least one of the input information received from the external device 40 and the information held by the external device 30 to the battery status determination device 10.

[0102] As shown in Figure 1, the external device 40 is configured to communicate with the external device 30 and may also be referred to as the terminal 40. The external device 40 is a device for use by the user of the battery status determination device 10. The external device 40 is configured to display the battery status determination results transmitted from the external device 30. The external device 40 is also configured to receive input information necessary for battery status determination from the user of the battery status determination device 10 and to transmit the input information to the external device 30. Examples of the external device 40 include smartphones, tablet computers, and personal computers. The external device 40 may also be configured to communicate with the battery status determination device 10.

[0103] The external device 40 comprises a controller 42, an interface 43, and a display 44. The interface 43 and the display 44 are electrically connected to the controller 42. The display 44 is electrically connected to the controller 42 and configured to display information. The controller 42 is configured to control the display 44 to display information.

[0104] The controller 42 includes, for example, a processor 42P, memory 42M, a circuit board 42C, and a bus 42B. The processor 42P includes, for example, a CPU and / or MPU. The memory 42M includes, for example, volatile and / or non-volatile memory. Examples of volatile memory include RAM and / or DRAM. Examples of non-volatile memory include ROM and EEPROM. The memory 42M may also be referred to as a computer-readable storage medium. The processor 42P and the memory 42M are electrically mounted on the circuit board 42C. The processor 42P and the memory 42M are electrically connected to each other via the circuit board 42C. The processor 42P may also be referred to as a hardware processor 42P. The memory 42M may also be referred to as hardware memory 42M.

[0105] The controller 42 is programmed to implement the control algorithm for the external device 40. The controller 42's memory 42M stores software, such as a program for implementing the control algorithm for the external device 40. The processor 42P implements the control algorithm for the external device 40 by reading and executing the program stored in memory 42M.

[0106] The configuration of the controller 42 is not limited to a processor 42P, memory 42M, circuit board 42C, and bus 42B. The configuration of the controller 42 can be realized by hardware alone or by a combination of hardware and software. Furthermore, the processor 42P and memory 42M may be configured on a single chip, such as an ASIC or FPGA. Note that the controller 42 may also be referred to as a controller circuit 42, controller circuitry 42, circuit 42, and / or circuitry 42.

[0107] Interface 43 is electrically connected to the processor 42P and memory 42M via the circuit board 42C and bus 42B. Interface 43 includes a user interface 45 and a communication unit 46.

[0108] The user interface 45 is electrically connected to the controller 42. The user interface 45 is electrically connected to the processor 42P and memory 42M via the circuit board 42C and bus 42B. The user interface 45 is configured to receive input information from the user. The controller 42 stores the input information received from the user interface 45 in memory 42M. Examples of the user interface 45 include a keyboard, mouse, and touch panel.

[0109] The communication unit 46 is electrically connected to the controller 42. The communication unit 46 is electrically connected to the processor 42P and memory 42M via the circuit board 42C and bus 42B. The communication unit 46 is configured to communicate with an external device 30. The communication unit 46 includes a wireless communication circuit. The wireless communication circuit is electrically connected to the controller 42 and is configured to communicate wirelessly with the external device 30 via the internet.

[0110] Similar to the communication unit 24, the wireless communication circuit of the communication unit 46 includes, for example, an antenna, a wireless transmitting circuit, and a wireless receiving circuit. The antenna is electrically connected to the wireless transmitting circuit and the wireless receiving circuit. The wireless transmitting circuit is configured to transmit a signal wirelessly via the antenna. The wireless receiving circuit is configured to receive a signal wirelessly via the antenna. The wireless transmitting circuit is configured to encrypt a signal using a predetermined protocol. The wireless receiving circuit is configured to decrypt a wireless signal using a predetermined protocol.

[0111] As shown in Figure 3, the communication unit 46 is configured to transmit input information to the external device 30 via the Internet. The communication unit 46 is configured to receive the battery status determination result BR transmitted from the external device 30 via the Internet. The display 44 of the external device 40 is configured to display the battery status determination result BR.

[0112] As shown in Figure 1, the battery status determination device 10 includes an alerting device 26. The alerting device 26 is electrically connected to the controller 14. The alerting device 26 is electrically connected to the processor 14P and memory 14M via the circuit board 14C and bus 14B. The controller 14 is configured to control the alerting device 26 to display information. The alerting device 26 operates on electricity supplied from the controller 14.

[0113] The notification device 26 is configured to notify the user of the battery status determination result. The notification device 26 includes, for example, at least one of an indicator, a display, and a speaker. The controller 14 is configured to control the notification device 26 so that it notifies the user of the battery status determination result. For example, the notification device 26 is configured to notify the user that the rechargeable battery 2 needs to be replaced. The controller 14 is configured to control the notification device 26 so that it notifies the user that the rechargeable battery 2 needs to be replaced.

[0114] The operation of the battery status determination system 8 will be described with reference to Figures 3 and 4. As shown in Figure 4, the controller 14 of the battery status determination device 10 is configured to execute the battery status determination method described below. The controller 14 stores the battery status determination program in memory 14M. That is, a storage medium readable by the computer stores the battery status determination program. The battery status determination program causes the computer to execute the battery status determination method. The processor 14P of the controller 14 realizes the battery status determination method described below by reading and executing the battery status determination program stored in memory 14M.

[0115] As shown in Figure 4, the battery state determination method includes the controller 14 determining whether the rechargeable battery 2 is charging or discharging (for example, step S2), and the controller 14 separately calculating the charging resistance value RC during charging and the discharging resistance value RD during discharging of the rechargeable battery 2 (for example, steps S11 to S15 and S21 to S25).

[0116] The controller 14 acquires the current value A1 and voltage value V1 of the rechargeable battery 2 (step S1). The controller 14 acquires the measured current value A1 of the current sensor 16. The controller 14 acquires the measured voltage value V1 of the voltage sensor 18. The current value A1 and voltage value V1 are temporarily stored in the controller 14's memory 14M.

[0117] The controller 14 determines whether the rechargeable battery 2 is charging or discharging (step S2). The controller 14 determines whether the rechargeable battery 2 is charging or discharging based on the sign of the current value A1. If the sign of the current value A1 is either positive or negative (for example, positive), the controller 14 obtains the current value A1 as the charging current value AC and the voltage value V1 as the charging voltage value VC (step S3). On the other hand, if the sign of the current value A1 is the other of positive or negative (for example, negative), the controller 14 obtains the current value A1 as the discharge current value AD and the voltage value V1 as the discharge voltage value VD (step S4).

[0118] If it is determined in step S2 that charging is in progress based on the current value A1, the controller 14 determines whether the previous current value A2 was obtained during charging or discharging (step S10). If it is determined that the previous current value A2 was obtained during discharging, the current value A1 and voltage value V1 are stored in memory 14M as the previous current value A2 and the previous voltage value V2 (step S5), and the process returns to step S1.

[0119] On the other hand, if it is determined that the previous current value A2 was obtained during charging, the controller 14 calculates the charging current difference ΔAC and the charging voltage difference ΔVC based on the above equations (1) and (2) (step S11).

[0120] Based on the charging current difference ΔAC, the charging voltage difference ΔVC, and the aforementioned formula (3A), the controller 14 calculates the current charging resistance value RC1 (step S12). The current charging resistance value RC1 is stored in memory 14M. The current charging resistance value RC1 is corrected by the controller 14 based on at least one of the temperature and the estimated charge rate (step S12A). The corrected current charging resistance value RC1 is stored in memory 14M. Based on the current charging resistance value RC1, the previous charging resistance value RC2, and the aforementioned formula (4), the controller 14 calculates the charging resistance value RC (step S13). Note that the correction in step S12A may be performed as needed. The necessity of the correction in step S12A may be selected according to the conditions. Alternatively, the correction process may be omitted from the battery state determination method.

[0121] To determine the status of the rechargeable battery 2, the charging resistance value RC is compared with the charging resistance threshold TC by the controller 14 (step S14). If the charging resistance value RC is less than the charging resistance threshold TC, the process proceeds to step S5 (step S14). On the other hand, if the charging resistance value RC is equal to or greater than the charging resistance threshold TC, the notification device 26 notifies the user of the battery status determination result BR indicating that the rechargeable battery 2 needs to be replaced (steps S14 and S15). If the charging resistance value RC is equal to or greater than the charging resistance threshold TC, the battery status determination result BR is transmitted from the battery status determination device 10 to the external device 40 via the internet and the external device 30 (step S16, see Figure 3). The battery status determination result BR is displayed on the display 44 of the external device 40 (step S17).

[0122] To use in the calculation of the next discharge resistance value RD, the current value A1 is stored in memory 14M as the previous charging current value AC2, and the voltage value V1 is stored in memory 14M as the previous charging voltage value VC2 (step S18). The charging resistance value RC calculated in step S13 is stored in memory 14M as the previous charging resistance value RC2 (step S19). The process returns to step S1 via step S5.

[0123] Furthermore, if it is determined in step S2 that the device is discharging based on the current value A1, the controller 14 determines whether the previous current value A2 was obtained during charging or discharging (step S20). If it is determined that the previous current value A2 was obtained during charging, the current value A1 and voltage value V1 are stored in memory 14M as the previous current value A2 and the previous voltage value V2 (step S5), and the process returns to step S1.

[0124] On the other hand, if it is determined that the previous current value A2 was obtained during discharge, the controller 14 calculates the discharge current difference ΔAD and the discharge voltage difference ΔVD based on the aforementioned equations (5) and (6) (step S21).

[0125] Based on the discharge current difference ΔAD, the discharge voltage difference ΔVD, and the aforementioned equation (7A), the controller 14 calculates the current discharge resistance value RD1 (step S22). The current discharge resistance value RD1 is stored in memory 14M. The current discharge resistance value RD1 is corrected by the controller 14 based on temperature and at least one of the estimated discharge rate (step S22A). The corrected current discharge resistance value RD1 is stored in memory 14M. Based on the current discharge resistance value RD1, the previous discharge resistance value RD2, and the aforementioned equation (8), the controller 14 calculates the discharge resistance value RD (step S23).

[0126] To determine the status of the rechargeable battery 2, the discharge resistance value RD is compared with the discharge resistance threshold TD by the controller 14 (step S24). If the discharge resistance value RD is less than the discharge resistance threshold TD, the process proceeds to step S5 (step S24). On the other hand, if the discharge resistance value RD is equal to or greater than the discharge resistance threshold TD, the notification device 26 notifies the user of the battery status determination result BR indicating that the rechargeable battery 2 needs to be replaced (steps S24 and S25). If the discharge resistance value RD is equal to or greater than the discharge resistance threshold TD, the battery status determination result BR is transmitted from the battery status determination device 10 to the external device 40 via the internet and the external device 30 (step S26, see Figure 3). The battery status determination result BR is displayed on the display 44 of the external device 40 (step S27).

[0127] To use in the calculation of the next discharge resistance value RD, the current value A1 is stored in memory 14M as the previous discharge current value AD2, and the voltage value V1 is stored in memory 14M as the previous discharge voltage value VD2 (step S28). The discharge resistance value RD calculated in step S23 is stored in memory 14M as the previous discharge resistance value RD2 (step S29). The process returns to step S2 via step S5.

[0128] As described above, the battery state determination system 8 and the battery state determination device 10 include a controller 14 configured to determine whether the rechargeable battery 2 is charging or discharging. The controller 14 is configured to separately calculate the charging resistance value RC during charging and the discharge resistance value RD during discharging of the rechargeable battery 2. The battery state determination method includes determining whether the rechargeable battery 2 is charging or discharging using the controller 14, and separately calculating the charging resistance value RC during charging and the discharge resistance value RD during discharging of the rechargeable battery 2 using the controller 14. Therefore, the accuracy of calculating the internal resistance of the rechargeable battery 2 can be improved.

[0129] Furthermore, by using the charging resistance value RC and the discharge resistance value RD appropriately depending on whether it is preferable to use the charging resistance value RC or the discharge resistance value RD, the accuracy of each process can be improved. An example of a case where it is preferable to use the charging resistance value RC is when determining whether or not the rechargeable battery 2 has reached full charge. An example of a case where it is preferable to use the discharge resistance value RD is when calculating the expected voltage when a predetermined required current flows. In addition, the accuracy of determinations can be improved by performing determinations on the charging resistance value RC, the discharge resistance value RD, and the values ​​calculated using these values, respectively, when determining whether or not the rechargeable battery 2 needs to be replaced (degradation determination), when determining the discharge performance of the rechargeable battery 2, and when determining whether or not to perform idle stop.

[0130] Second Embodiment Referring to Figures 5 to 7, the battery state determination system 208, which includes the battery state determination device 210 according to the second embodiment, will be described below. Except for the battery state determination method, the battery state determination system 208 has substantially the same structure as the battery state determination system 8 according to the first embodiment. The battery state determination device 210 has substantially the same structure as the battery state determination device 10 according to the first embodiment. Therefore, components having substantially the same structure as the components of the first embodiment are given the same numbers here, and for the sake of simplification, they will not be described and / or illustrated again in detail.

[0131] As shown in Figure 5, the battery status determination system 208 includes a controller 14, a current sensor 16, a voltage sensor 18, a temperature sensor 19, an interface 20, and a notification device 26. The battery status determination device 210 includes a controller 14, a current sensor 16, a voltage sensor 18, a temperature sensor 19, an interface 20, and a notification device 26. The battery status determination system 208 has substantially the same configuration as the battery status determination system 8 of the first embodiment. The battery status determination device 210 has substantially the same configuration as the battery status determination device 10 of the first embodiment.

[0132] As shown in Figure 6, similar to the first embodiment, the controller 14 is configured to separately calculate the charging resistance value RC during charging and the discharge resistance value RD during discharging of the rechargeable battery 2. The controller 14 is configured to calculate the charging resistance value RC based on the charging current value AC. The controller 14 is configured to calculate the discharge resistance value RD based on the discharge current value AD. The controller 14 is configured to calculate the charging resistance value RC based on the charging current value AC and the charging voltage value VC. The controller 14 is configured to calculate the discharge resistance value RD based on the discharge current value AD and the discharge voltage value VD.

[0133] In the second embodiment, the charging resistance value RC includes a first charging resistance value RC11 and a second charging resistance value RC12. The discharge resistance value RD includes a first discharge resistance value RD11 and a second discharge resistance value RD12.

[0134] The controller 14 is configured to calculate a first charging resistance value RC11 based on the charging current difference ΔAC and the charging voltage difference ΔVC when the sign of the charging current difference ΔAC is either positive or negative. The controller 14 is configured to calculate a second charging resistance value RC12 based on the charging current difference ΔAC and the charging voltage difference ΔVC when the sign of the charging current difference ΔAC is either positive or negative. The controller 14 stores the first charging resistance value RC11 in memory 14M. The controller 14 stores the second charging resistance value RC12 in memory 14M.

[0135] For example, the controller 14 is configured to calculate a first charging resistance value RC11 based on the charging current difference ΔAC and the charging voltage difference ΔVC when the sign of the charging current difference ΔAC is positive. The controller 14 is configured to calculate a second charging resistance value RC12 based on the charging current difference ΔAC and the charging voltage difference ΔVC when the sign of the charging current difference ΔAC is negative. However, the controller 14 may be configured to calculate the first charging resistance value RC11 based on the charging current difference ΔAC and the charging voltage difference ΔVC when the sign of the charging current difference ΔAC is negative. The controller 14 may be configured to calculate the second charging resistance value RC12 based on the charging current difference ΔAC and the charging voltage difference ΔVC when the sign of the charging current difference ΔAC is positive.

[0136] The controller 14 is configured to calculate a first discharge resistance value RD11 based on the discharge current difference ΔAD and the discharge voltage difference ΔVD when the sign of the discharge current difference ΔAD is either positive or negative. The controller 14 is configured to calculate a second discharge resistance value RD12 based on the discharge current difference ΔAD and the discharge voltage difference ΔVD when the sign of the discharge current difference ΔAD is either positive or negative. The controller 14 stores the first discharge resistance value RD11 in memory 14M. The controller 14 stores the second discharge resistance value RD12 in memory 14M.

[0137] For example, the controller 14 is configured to calculate a first discharge resistance value RD11 based on the discharge current difference ΔAD and the discharge voltage difference ΔVD when the sign of the discharge current difference ΔAD is positive. The controller 14 is configured to calculate a second discharge resistance value RD12 based on the discharge current difference ΔAD and the discharge voltage difference ΔVD when the sign of the discharge current difference ΔAD is negative. However, the controller 14 may be configured to calculate the first discharge resistance value RD11 based on the discharge current difference ΔAD and the discharge voltage difference ΔVD when the sign of the discharge current difference ΔAD is negative. The controller 14 may be configured to calculate the second discharge resistance value RD12 based on the discharge current difference ΔAD and the discharge voltage difference ΔVD when the sign of the discharge current difference ΔAD is positive.

[0138] The controller 14 is configured to calculate the charging resistance value RC based on one of the following equations (13) and (14).

[0139] RC=∫(ΔVC / ΔAC)dt ···(13) RC=∫(ΔAC×ΔVC)dt / ∫(ΔAC×ΔAC)dt ···(14) For example, the controller 14 is configured to calculate the first charging resistance value RC11 based on one of the following equations (13A) and (14A).

[0140] RC11=∫(ΔVC / ΔAC)dt ···(13A) RC11=∫(ΔAC×ΔVC)dt / ∫(ΔAC×ΔAC)dt ···(14A) The controller 14 is configured to calculate the second charging resistance value RC12 based on one of the following equations (13B) and (14B).

[0141] RC12=∫(ΔVC / ΔAC)dt ···(13B) RC12=∫(ΔAC×ΔVC)dt / ∫(ΔAC×ΔAC)dt ···(14B) Similarly, the controller 14 is configured to calculate the discharge resistance value RD based on one of the following equations (15) and (16).

[0142] RD=∫(ΔVD / ΔAD)dt ···(15) RD=∫(ΔAD×ΔVD)dt / ∫(ΔAD×ΔAD)dt ···(16) For example, the controller 14 is configured to calculate the first discharge resistance value RD11 based on one of the following equations (15A) and (16A).

[0143] RD11=∫(ΔVD / ΔAD)dt ···(15A) RD11=∫(ΔAD×ΔVD)dt / ∫(ΔAD×ΔAD)dt ···(16A) The controller 14 is configured to calculate the second discharge resistance value RD12 based on one of the following equations (15B) and (16B).

[0144] RD12=∫(ΔVD / ΔAD)dt ···(15B) RD12=∫(ΔAD×ΔVD)dt / ∫(ΔAD×ΔAD)dt ···(16B) As shown in Figure 7, the controller 14 is configured to calculate the first charging resistance value RC11, the second charging resistance value RC12, the first discharge resistance value RD11, and the second discharge resistance value RD12 based on the aforementioned equations (14) and (16) (for example, equations (14A), (14B), (16A), and (16B)) instead of equations (3), (3A), (4), (7), (7A), and (8) of the first embodiment.

[0145] The aforementioned equations (13), (14), (15), (16), (13A), (13B), (14A), (14B), (15A), (15B), (16A), and (16B) are merely examples of methods for calculating the charging resistance RC and the discharging resistance RD. Therefore, for example, the above integral calculation may be reset each time a predetermined condition (e.g., a predetermined amount of time has elapsed) is met, or it may be performed periodically at predetermined intervals.

[0146] As shown in Figure 7, in the battery state determination device 210, steps S1 to S5, S10, S11, S20, and S21 shown in Figure 4 are executed by the controller 14.

[0147] After step S11 is performed, the controller 14 determines whether the sign of the charging current difference ΔAC is positive or negative (step S33). If the sign of the charging current difference ΔAC is negative (i.e., the charging current difference ΔAC decreases), the controller 14 calculates the first charging resistance value RC11 based on the charging current difference ΔAC, the charging voltage difference ΔVC, and equation (14A) (step S34). If the sign of the charging current difference ΔAC is positive (i.e., the charging current difference ΔAC increases), the controller 14 calculates the second charging resistance value RC12 based on the charging current difference ΔAC, the charging voltage difference ΔVC, and equation (14B) (step S35).

[0148] The first charging resistance value RC11 is corrected by the controller 14 based on temperature and at least one of the estimated charge rate (step S34A). The corrected first charging resistance value RC11 is stored in memory 14M. Similarly, the second charging resistance value RC12 is corrected by the controller 14 based on temperature and at least one of the estimated charge rate (step S35A). The corrected second charging resistance value RC12 is stored in memory 14M.

[0149] To determine the state of the rechargeable battery 2, the first charging resistance value RC11 is compared with the first charging resistance threshold TC11 by the controller 14 (step S36). The first charging resistance threshold TC11 is set to a value suitable for determination based on the first charging resistance value RC11. If the first charging resistance value RC11 is less than the first charging resistance threshold TC11, the process proceeds to step S5 (step S36). On the other hand, if the first charging resistance value RC11 is greater than or equal to the first charging resistance threshold TC11, the battery state determination result BR indicating that the rechargeable battery 2 needs to be replaced is notified to the user by the notification device 26 (steps S36 and S15). The first charging resistance threshold TC11 is stored in memory 14M.

[0150] To determine the state of the rechargeable battery 2, the second charging resistance value RC12 is compared with the second charging resistance threshold TC12 by the controller 14 (step S37). The second charging resistance threshold TC12 is set to a value suitable for determination based on the second charging resistance value RC12. If the second charging resistance value RC12 is less than the second charging resistance threshold TC12, the process proceeds to step S5 (step S37). On the other hand, if the second charging resistance value RC12 is greater than or equal to the second charging resistance threshold TC12, the battery state determination result BR indicating that the rechargeable battery 2 needs to be replaced is notified to the user by the notification device 26 (steps S37 and S15). The second charging resistance threshold TC12 is stored in memory 14M.

[0151] After steps S15-S18 and S5 are executed, the process is repeated from step S1 at a predetermined interval.

[0152] Furthermore, after step S21 is executed, the controller 14 determines whether the sign of the discharge current difference ΔAD is positive or negative (step S43). If the sign of the discharge current difference ΔAD is negative (i.e., the discharge current difference ΔAD decreases), the controller 14 calculates the first discharge resistance value RD11 based on the discharge current difference ΔAD, the discharge voltage difference ΔVD, and equation (16A) (step S44). If the sign of the discharge current difference ΔAD is positive (i.e., the discharge current difference ΔAD increases), the controller 14 calculates the second discharge resistance value RD12 based on the discharge current difference ΔAD, the discharge voltage difference ΔVD, and equation (16) (step S45).

[0153] The first discharge resistance value RD11 is corrected by the controller 14 based on temperature and at least one of the estimated discharge rate (step S44A). The corrected first discharge resistance value RD11 is stored in memory 14M. Similarly, the second discharge resistance value RD12 is corrected by the controller 14 based on temperature and at least one of the estimated discharge rate (step S45A). The corrected second discharge resistance value RD12 is stored in memory 14M.

[0154] To determine the state of the rechargeable battery 2, the first discharge resistance value RD11 is compared with the first discharge resistance threshold TD11 by the controller 14 (step S46). The first discharge resistance threshold TD11 is set to a value suitable for determination based on the first discharge resistance value RD11. If the first discharge resistance value RD11 is less than the first discharge resistance threshold TD11, the process proceeds to step S5 (step S46). On the other hand, if the first discharge resistance value RD11 is greater than or equal to the first discharge resistance threshold TD11, the battery state determination result BR indicating that the rechargeable battery 2 needs to be replaced is notified to the user by the notification device 26 (steps S46 and S25). The first discharge resistance threshold TD11 is stored in memory 14M.

[0155] To determine the state of the rechargeable battery 2, the second discharge resistance value RD12 is compared with the second discharge resistance threshold TD12 by the controller 14 (step S47). The second discharge resistance threshold TD12 is set to a value suitable for determination based on the second discharge resistance value RD12. If the second discharge resistance value RD12 is less than the second discharge resistance threshold TD12, the process proceeds to step S5 (step S47). On the other hand, if the second discharge resistance value RD12 is greater than or equal to the second discharge resistance threshold TD12, the battery state determination result BR indicating that the rechargeable battery 2 needs to be replaced is notified to the user by the notification device 26 (steps S47 and S25). The second discharge resistance threshold TD12 is stored in memory 14M.

[0156] After steps S25-S28 and S5 are executed, the process is repeated from step S1 at a predetermined interval.

[0157] In steps S34, S35, S44, and S45, the first charging resistance value RC11, the second charging resistance value RC12, the first discharge resistance value RD11, and the second discharge resistance value RD12 may be calculated based on formulas (13A), (13B), (15A), and (15B) instead of formulas (14A), (14B), (16A), and (16B).

[0158] As described above, the battery state determination device 210 includes a controller 14 configured to determine whether the rechargeable battery 2 is charging or discharging. The controller 14 is configured to separately calculate the charging resistance value RC during charging and the discharge resistance value RD during discharging of the rechargeable battery 2. The battery state determination method includes determining whether the rechargeable battery 2 is charging or discharging using the controller 14, and separately calculating the charging resistance value RC during charging and the discharge resistance value RD during discharging of the rechargeable battery 2 using the controller 14. Therefore, the accuracy of calculating the internal resistance of the rechargeable battery 2 can be improved. Furthermore, the same effects as those of the battery state determination system 8 and battery state determination device 10 according to the first embodiment can be obtained.

[0159] In the first embodiment described above, steps S1 to S5, S10 to S16, S18 to S26, and S27 to S29 are performed in the battery state determination system 8 and the battery state determination device 10. However, as will be explained below, at least a portion of steps S1 to S5, S10 to S16, S18 to S26, and S27 to S29 may be performed in the external device 30.

[0160] For example, in the battery state determination system 308 according to the first modified example shown in Figure 8, steps S14 and S24 are executed in the determination device 330 corresponding to the external device 30, as shown in Figure 9. As shown in Figure 8, the battery state determination system 308 includes a battery state determination device 310 and an external device 40. The battery state determination device 310 comprises a battery management device 311, a determination device 330, and an external device 40. The basic configuration of the battery management device 311 is substantially the same as the basic configuration of the battery state determination device 10. The basic configuration of the determination device 330 is substantially the same as the basic configuration of the external device 30. A part of the battery state determination program is stored in the memory 32M of the controller 32 of the determination device 330, and is read by the processor 32P of the controller 32, so that steps S14 and S24 are executed by the determination device 330.

[0161] As shown in Figures 8 and 9, the battery management device 311 obtains the charging resistance value RC and the discharge resistance value RD by executing steps S1 to S5, S10 to S13, and S20 to S23. The battery management device 311 transmits the charging resistance value RC or the discharge resistance value RD to the determination device 330 (steps S330 and S340). The determination device 330 determines whether or not the rechargeable battery 2 needs to be replaced by executing steps S14 and S24. If the determination device 330 determines that the rechargeable battery 2 needs to be replaced, it transmits the battery status determination result BR to the battery management device 311 and the external device 40 (steps S331 and S341). The notification device 26 of the battery management device 311 notifies the user of the battery status determination result BR (steps S15 and S25). The display 44 of the external device 40 displays the battery status determination result BR (steps S17 and S27).

[0162] Furthermore, in the battery state determination system 408 according to the second modified example shown in Figure 10, as shown in Figure 11, steps S12 to S14 and S22 to S24 are executed in the determination device 430 corresponding to the external device 30. As shown in Figure 10, the battery state determination system 408 includes a battery state determination device 410 and an external device 40. The battery state determination device 410 comprises a battery management device 411, a determination device 430, and an external device 40. The basic configuration of the battery management device 411 is substantially the same as the basic configuration of the battery state determination device 10. The basic configuration of the determination device 430 is substantially the same as the basic configuration of the external device 30. A part of the battery state determination program is stored in the memory 32M of the controller 32 of the determination device 430, and is read by the processor 32P of the controller 32, so that steps S12 to S14 and S22 to S24 are executed by the determination device 430.

[0163] As shown in Figures 10 and 11, the battery management device 411 obtains the charging current difference ΔAC, charging voltage difference ΔVC, discharge current difference ΔAD, and discharge voltage difference ΔVD by performing steps S1 to S5, S10, S11, S20, and S21. The battery management device 411 transmits the charging current difference ΔAC, charging voltage difference ΔVC, discharge current difference ΔAD, and discharge voltage difference ΔVD to the determination device 430 (steps S430 and S440). The determination device 430 obtains the charging resistance value RC and discharge resistance value RD of the rechargeable battery 2 by performing steps S12 to S14 and S22 to S24, and determines whether the rechargeable battery 2 needs to be replaced. If the determination device 430 determines that the rechargeable battery 2 needs to be replaced, it transmits the battery status determination result BR to the battery management device 411 and the external device 40 (steps S431 and S441). The notification device 26 of the battery management device 411 notifies the user of the battery status determination result BR (steps S15 and S25). The display 44 of the external device 40 displays the battery status determination result BR (steps S17 and S27).

[0164] In the second modified example shown in Figures 10 and 11, steps S10, S11, S20, and S21 may be performed by the determination device 430. In this case, the battery management device 511 transmits the current value A1 and the voltage value V1 to the determination device 430.

[0165] The first and second modified examples shown in Figures 8 to 11 are also applicable to the battery state determination system 208 according to the second embodiment.

[0166] The configuration of the battery state determination system 8 according to the first embodiment and the configuration of the battery state determination system 208 according to the second embodiment are interchangeable. The configuration of the battery state determination device 10 according to the first embodiment and the configuration of the battery state determination device 210 according to the second embodiment are interchangeable. For example, in the battery state determination method shown in Figure 4, the calculations in steps S34, S35, S45, and S46 of Figure 7 (calculations of equations (14) and (16)) can be applied instead of the calculations in steps S13 and S23 (calculations of equations (4) and (8)), and the calculations of equations (13) and (15) can also be applied. Similarly, in the battery state determination method shown in Figure 7, the calculations in steps S13 and S23 of Figure 4 (calculations of equations (4) and (8)) can be applied instead of the calculations in steps S34, S35, S45, and S46 (calculations of equations (14) and (16)).

[0167] Furthermore, the battery status determination systems 8 and 208, battery status determination devices 10 and 210, battery management devices 311 and 411, battery status determination method, and battery status determination program according to the above-described embodiments and the first and second modifications are applicable, for example, to privately owned vehicles, vehicles used as rental cars, and vehicles used for car sharing. When at least one of the battery status determination systems 8 and 208, battery status determination devices 10 and 210, and battery management devices 311 and 411 is applied to a privately owned vehicle, for example, the external device 40 is used by the vehicle owner or driver to monitor the polarity of the rechargeable battery 2 installed in the vehicle. When at least one of the battery status determination systems 8 and 208, battery status determination devices 10 and 210, and battery management devices 311 and 411 is applied to a vehicle used as a rental car, for example, the external device 40 is used by the rental car company and its staff to monitor the polarity of the rechargeable battery 2 installed in the rented vehicle. Furthermore, if at least one of the battery status determination systems 8 and 208, battery status determination devices 10 and 210, and battery management devices 311 and 411 is applied to a vehicle used for car sharing, for example, the external device 40 is used by the car sharing company and its staff to monitor the polarity of the rechargeable battery 2 installed in the shared vehicle.

[0168] Furthermore, the battery status determination systems 8 and 208, battery status determination devices 10 and 210, battery management devices 311 and 411, battery status determination method, and battery status determination program described above, as well as the first to third modified examples, are applicable to devices other than vehicles. For example, they can be used to monitor rechargeable batteries that store electricity generated by solar power generation systems, etc.

[0169] It should be noted that the battery status determination systems 8 and 208 described above are merely examples of battery status determination systems, and the configuration of a battery status determination system is not limited to the configurations of battery status determination systems 8 and 208. For example, in the above-described embodiment, battery status determination system 8 includes a battery status determination device 10, an external device 30, and an external device 40, but at least one of the external devices 30 and 40 may be omitted from battery status determination system 8, or battery status determination system 8 may include other configurations. The same applies to battery status determination system 208 and its variations. Also, battery status determination system 8 includes a current sensor 16, a voltage sensor 18, an interface 20, a notification device 26, and a power supply circuit 14S, but at least one of the current sensor 16, voltage sensor 18, interface 20, notification device 26, and power supply circuit 14S may be omitted from battery status determination system 8, or battery status determination system 8 may include other configurations. If at least one of the current sensor 16, voltage sensor 18, interface 20, notification device 26, and power supply circuit 14S is omitted from the battery state determination system 8, the battery state determination system 8 may be configured to obtain the necessary information (e.g., current value, voltage value) from outside the battery state determination system 8. The same applies to the battery state determination system 208 and its variations.

[0170] The battery status determination devices 10 and 210 described above are merely examples of battery status determination devices, and the configuration of a battery status determination device is not limited to the configurations of battery status determination devices 10 and 210. For example, in the above embodiments, the battery status determination device 10 includes a current sensor 16, a voltage sensor 18, an interface 20, a notification device 26, and a power supply circuit 14S, but at least one of the current sensor 16, voltage sensor 18, interface 20, notification device 26, and power supply circuit 14S may be omitted from the battery status determination device 10. If at least one of the current sensor 16, voltage sensor 18, interface 20, notification device 26, and power supply circuit 14S is omitted from the battery status determination device 10, the battery status determination device 10 may be configured to obtain the necessary information (e.g., current value, voltage value) from outside the battery status determination device 10. The same applies to the battery status determination device 210 and its variations.

[0171] In this application, "equipped with" and its derivatives are non-restrictive terms that describe the existence of a component and do not exclude the existence of other components not described. This also applies to "have," "include," and their derivatives.

[0172] In this application, ordinal numbers such as "first" and "second" are merely terms used to identify the components and do not have any other meaning (e.g., a specific order). For example, the existence of a "first element" does not implicitly mean that a "second element" exists, nor does the existence of a "second element" implicitly mean that a "first element" exists.

[0173] Words expressing degree, such as "substantially," "about," and "approximately," may mean a reasonable deviation that does not significantly alter the final result. All numerical values ​​described in this application may be interpreted as including words such as "substantially," "about," and "approximately."

[0174] Furthermore, the expression "at least one of A and B" in this disclosure includes, for example, (1) A only, (2) B only, and (3) both A and B. The expression "at least one of A, B, and C" includes, for example, (1) A only, (2) B only, (3) C only, (4) A and B, (5) B and C, (6) A and C, and (7) all of A, B, and C. In this disclosure, the expression "at least one of A and B" is not construed as "at least one of A and at least one of B".

[0175] Based on the above disclosure, it is clear that various changes and modifications to the present invention are possible. Therefore, the present invention may be implemented in a manner different from the specific disclosures of this application, without departing from the spirit of the invention. [Explanation of Symbols]

[0176] 2: Rechargeable battery 4: Load 6: Charging circuit 8, 208, 308, 408: Battery status determination system 10, 210, 310, 410: Battery status determination device 14: Controller 16: Current sensor 18: Voltage sensor

Claims

1. A controller configured to determine whether a rechargeable battery is charging or discharging is included. The controller is configured to be able to separately calculate the charging resistance value during charging and the discharge resistance value during discharging of the rechargeable battery. The controller is configured to acquire the current value of the rechargeable battery, The controller is configured to determine whether the rechargeable battery is charging or discharging based on the sign of the current value. The controller is configured to acquire the current value and voltage value of the rechargeable battery as the charging current value and charging voltage value during the charging of the rechargeable battery. The controller is configured to periodically acquire the charging current value and the charging voltage value. The controller is configured to calculate the charging current difference by subtracting the previous charging current value from the latest charging current value. The controller is configured to calculate the charging voltage difference by subtracting the previous charging voltage value from the latest charging voltage value. The controller is configured to separately calculate a first charging resistance value and a second charging resistance value, each corresponding to the sign of the charging current difference, based on a plurality of charging current differences and a plurality of charging voltage differences obtained during the charging of the rechargeable battery. Battery status determination system.

2. The controller is configured to calculate the first charging resistance value based on the charging current difference and the charging voltage difference when the sign of the charging current difference is either positive or negative. The controller is configured to calculate the second charging resistance value based on the charging current difference and the charging voltage difference when the sign of the charging current difference is either positive or negative. The battery state determination system according to claim 1.

3. The controller, when the charging resistance value is RC, the charging current difference is ΔAC, and the charging voltage difference is ΔVC, RC = ∫(ΔVC / ΔAC) dt, and, RC=∫(ΔAC×ΔVC)dt / ∫(ΔAC×ΔAC)dt The system is configured to calculate the first charging resistance value and the second charging resistance value based on one of the following: The battery state determination system according to claim 1 or 2.

4. The controller is configured to acquire the current value and voltage value of the rechargeable battery as the discharge current value and discharge voltage value during the discharge of the rechargeable battery, The controller is configured to periodically acquire the discharge current value and the discharge voltage value. The controller is configured to calculate the discharge current difference by subtracting the previous discharge current value from the latest discharge current value. The controller is configured to calculate the discharge voltage difference by subtracting the previous discharge voltage value from the latest discharge voltage value. The controller is configured to separately calculate a first discharge resistance value and a second discharge resistance value, each corresponding to the sign of the discharge current difference, based on a plurality of discharge current differences and a plurality of discharge voltage differences obtained during the discharge of the rechargeable battery. A battery state determination system according to any one of claims 1 to 3.

5. The controller is configured to acquire the current value as the charging current value when the sign of the current value is either positive or negative, The controller is configured to acquire the current value as the discharge current value when the sign of the current value is either positive or negative. The controller is configured to acquire the voltage value of the rechargeable battery as the charging voltage value when the sign of the current value is either positive or negative. The controller is configured to acquire the voltage value as the discharge voltage value when the sign of the current value is positive or negative, The battery status determination system according to claim 4.

6. A controller configured to determine whether a rechargeable battery is charging or discharging is included. The controller is configured to be able to separately calculate the charging resistance value during charging and the discharge resistance value during discharging of the rechargeable battery. The controller is configured to acquire the current value of the rechargeable battery, The controller is configured to determine whether the rechargeable battery is charging or discharging based on the sign of the current value. The controller is configured to acquire the current value and voltage value of the rechargeable battery as the discharge current value and discharge voltage value during the discharge of the rechargeable battery. The controller is configured to periodically acquire the discharge current value and the discharge voltage value. The controller is configured to calculate the discharge current difference by subtracting the previous discharge current value from the latest discharge current value. The controller is configured to calculate the discharge voltage difference by subtracting the previous discharge voltage value from the latest discharge voltage value. The controller is configured to separately calculate a first discharge resistance value and a second discharge resistance value, each corresponding to the sign of the discharge current difference, based on a plurality of discharge current differences and a plurality of discharge voltage differences obtained during the discharge of the rechargeable battery. Battery status determination system.

7. The controller is configured to acquire the current value as a charging current value when the sign of the current value is either positive or negative, The controller is configured to acquire the current value as the discharge current value when the sign of the current value is either positive or negative. The controller is configured to acquire the voltage value of the rechargeable battery as the charging voltage value when the sign of the current value is either positive or negative. The controller is configured to acquire the voltage value as the discharge voltage value when the sign of the current value is positive or negative, The battery status determination system according to claim 6.

8. The controller is configured to calculate the first discharge resistance value based on the discharge current difference and the discharge voltage difference when the sign of the discharge current difference is either positive or negative. The controller is configured to calculate the second discharge resistance value based on the discharge current difference and the discharge voltage difference when the sign of the discharge current difference is either positive or negative. A battery state determination system according to any one of claims 4 to 7.

9. The controller, when the discharge resistance value is RD, the discharge current difference is ΔAD, and the discharge voltage difference is ΔVD, RD = ∫(ΔVD / ΔAD) dt, and, RD=∫(ΔAD×ΔVD)dt / ∫(ΔAD×ΔAD)dt The system is configured to calculate the first discharge resistance value and the second discharge resistance value based on one of the following: A battery state determination system according to any one of claims 4 to 8.

10. The controller is configured to acquire at least one of the temperature and estimated charge level of the rechargeable battery. The controller is configured to correct at least one of the charging resistance value and the discharge resistance value based on at least one of the temperature and the estimated charge rate. A battery state determination system according to any one of claims 1 to 9.

11. The controller further comprises a current sensor electrically connected to the controller and configured to measure the current value of the rechargeable battery. A battery state determination system according to any one of claims 1 to 10.

12. The controller further comprises a voltage sensor electrically connected to the controller and configured to measure the voltage value of the rechargeable battery. A battery state determination system according to any one of claims 1 to 11.

13. A controller configured to determine whether a rechargeable battery is charging or discharging is included. The controller is configured to be able to separately calculate the charging resistance value during charging and the discharge resistance value during discharging of the rechargeable battery. The controller is configured to acquire the current value of the rechargeable battery, The controller is configured to determine whether the rechargeable battery is charging or discharging based on the sign of the current value. The controller is configured to acquire the current value and voltage value of the rechargeable battery as the charging current value and charging voltage value during the charging of the rechargeable battery. The controller is configured to periodically acquire the charging current value and the charging voltage value. The controller is configured to calculate the charging current difference by subtracting the previous charging current value from the latest charging current value. The controller is configured to calculate the charging voltage difference by subtracting the previous charging voltage value from the latest charging voltage value. The controller is configured to separately calculate a first charging resistance value and a second charging resistance value, each corresponding to the sign of the charging current difference, based on a plurality of charging current differences and a plurality of charging voltage differences obtained during the charging of the rechargeable battery. Battery status determination device.

14. A controller configured to determine whether a rechargeable battery is charging or discharging is included. The controller is configured to be able to separately calculate the charging resistance value during charging and the discharge resistance value during discharging of the rechargeable battery. The controller is configured to acquire the current value of the rechargeable battery, The controller is configured to determine whether the rechargeable battery is charging or discharging based on the sign of the current value. The controller is configured to acquire the current value and voltage value of the rechargeable battery as the discharge current value and discharge voltage value during the discharge of the rechargeable battery. The controller is configured to periodically acquire the discharge current value and the discharge voltage value. The controller is configured to calculate the discharge current difference by subtracting the previous discharge current value from the latest discharge current value. The controller is configured to calculate the discharge voltage difference by subtracting the previous discharge voltage value from the latest discharge voltage value. The controller is configured to separately calculate a first discharge resistance value and a second discharge resistance value, each corresponding to the sign of the discharge current difference, based on a plurality of discharge current differences and a plurality of discharge voltage differences obtained during the discharge of the rechargeable battery. Battery status determination device.

15. The controller determines whether the rechargeable battery is charging or discharging, and The controller separately calculates the charging resistance value during charging and the discharge resistance value during discharging of the rechargeable battery. The charging resistance value and the discharge resistance value are calculated separately by the controller, The controller obtains the current value of the rechargeable battery. The controller determines whether the rechargeable battery is charging or discharging based on the sign of the current value. The controller acquires the current value and voltage value of the rechargeable battery as the charging current value and charging voltage value while the rechargeable battery is being charged. The controller periodically acquires the charging current value and the charging voltage value. The controller calculates the charging current difference by subtracting the previous charging current value from the latest charging current value. The controller calculates the charging voltage difference by subtracting the previous charging voltage value from the latest charging voltage value, and The controller includes separately calculating a first charging resistance value and a second charging resistance value, corresponding to the sign of each charging current difference, based on a plurality of charging current differences and a plurality of charging voltage differences obtained during charging of the rechargeable battery, as the charging resistance values. Battery status determination method.

16. The controller determines whether the rechargeable battery is charging or discharging, and The controller separately calculates the charging resistance value during charging and the discharge resistance value during discharging of the rechargeable battery. The charging resistance value and the discharge resistance value are calculated separately by the controller, The controller obtains the current value of the rechargeable battery. The controller determines whether the rechargeable battery is charging or discharging based on the sign of the current value. The controller acquires the current value and voltage value of the rechargeable battery as the discharge current value and discharge voltage value during the discharge of the rechargeable battery. The controller periodically acquires the discharge current value and the discharge voltage value. The controller calculates the discharge current difference by subtracting the previous discharge current value from the latest discharge current value. The controller calculates the discharge voltage difference by subtracting the previous discharge voltage value from the latest discharge voltage value, and The controller includes separately calculating a first discharge resistance value and a second discharge resistance value corresponding to the sign of each discharge current difference, based on a plurality of discharge current differences and a plurality of discharge voltage differences obtained during the discharge of the rechargeable battery, as the discharge resistance values. Battery status determination method.

17. The computer is made to execute the battery state determination method according to claim 15 or 16. Battery status determination program.

18. The battery state determination program described in claim 17 is stored in A storage medium that can be read by a computer.

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