Internal resistance calculation device, battery control system, and internal resistance calculation method

Abstract

The internal resistance calculating device of the embodiment is provided with a current acquisition section, a voltage acquisition section, a charge amount calculation section, and an internal resistance calculation section. The current acquisition section acquires a battery current flowing in a battery. The voltage acquisition section acquires a battery voltage applied to the battery. The charge amount calculation section integrates the battery current acquired by the current acquisition section with respect to time, and calculates a charge amount moved to the battery. The internal resistance calculation section calculates an internal resistance of the battery based on a change amount of each of the battery current and the battery voltage until the charge amount calculated by the charge amount calculation section becomes equal to or greater than a threshold value set in advance.

Description

[0001] This application is an application filed in the Chinese national phase of international application PCT / JP2021 / 0001912 (international filing date: January 20, 2021), which is hereby incorporated by reference into this specification. In addition, this application is based on Japanese Patent Application No. 2020-049105 (filing date: March 19, 2020) for which priority is claimed, and the entire contents of the application are incorporated by reference into this specification. The present application contains subject matter related to that disclosed in Japanese Patent Application No. 2020-049105 filed in the Japanese national phase of the international application. The application claims priority from Japanese Patent Application No. 2020-049105 filed on March 19, 2020. The present application is based on and claims priority to Japanese Patent Application No. 2020-049105, filed on March 19, 2020, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] Embodiments of the present application relate to an internal resistance calculating device, a battery control system, and an internal resistance calculating method. BACKGROUND

[0003] A technology is being developed in which, in a case where an internal resistance of a battery is calculated for the purpose of deterioration diagnosis of the battery or the like, for a battery in a no-load state, a measurement of a battery voltage at 10 seconds from a start of a flow of a rectangular-wave rated current (pulse current) is performed with respect to a pulse current of four levels, and an absolute value of a slope of an approximate straight line formed by the pulse current of each level and the battery voltage measured at each level is calculated as the internal resistance. That is, the internal resistance of the battery is calculated on the basis of a variation amount of the pulse current flowing through the battery, that is, a current variation amount, and a variation amount of the battery voltage measured at each level, that is, a voltage variation amount. SUMMARY

[0004] PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] However, the above-described technology is premised on a test in which a controllable direct-current power source is used with respect to a battery cell, and is conditioned on the current flowing through the battery being a pulse current, and thus it is difficult to calculate the internal resistance of the battery with high accuracy in a case where the current flowing through the battery is not a pulse current.

[0006] MEANS FOR SOLVING THE PROBLEMS

[0007] The internal resistance calculating device of the embodiment includes a current acquisition unit, a voltage acquisition unit, a charge amount calculation unit, and an internal resistance calculation unit. The current acquisition unit acquires a battery current flowing through a battery. The voltage acquisition unit acquires a battery voltage applied to the battery. The charge amount calculation unit integrates the battery current acquired by the current acquisition unit with respect to time, and calculates a charge amount moved to the battery. The internal resistance calculation unit calculates an internal resistance of the battery on the basis of variation amounts of the battery current and the battery voltage each until the charge amount calculated by the charge amount calculation unit becomes equal to or greater than a threshold value set in advance. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a view showing an example of a configuration of a battery control system of the first embodiment.

[0009] Figure 2 is a block diagram showing an example of a functional configuration of the storage battery control device of the first embodiment.

[0010] Figure 3 is a diagram for explaining an example of a calculation process of the internal resistance in a case where the input current flowing in the battery system is a rated pulse current.

[0011] Figure 4 is a diagram for explaining an example of a calculation process of the internal resistance in a case where the input current flowing in the battery system is a lamp current.

[0012] Figure 5 is a diagram for explaining an example of a calculation process of the internal resistance of the battery cell in the storage battery control device of the first embodiment.

[0013] Figure 6 is a diagram for explaining an example of a calculation process of the internal resistance of the battery cell in the storage battery control device of the first embodiment.

[0014] Figure 7 is a flowchart showing an example of a flow of the calculation process of the internal resistance in the storage battery control device of the first embodiment.

[0015] Figure 8 is a block diagram showing an example of a functional configuration of the storage battery control device of the second embodiment. DETAILED DESCRIPTION

[0016] Hereinafter, an example of the internal resistance calculation device, the battery control system, and the internal resistance calculation method of the present embodiment will be described using the accompanying drawings.

[0017] (First Embodiment)

[0018] Figure 1 is a diagram showing an example of a configuration of the battery control system of the first embodiment. First, an example of a configuration of the battery control system of the present embodiment will be described using Figure 1 An example of a configuration of the battery control system of the present embodiment will be described.

[0019] As shown in Figure 1 , the battery control system of the present embodiment has a battery system 11 and a storage battery control device 10.

[0020] The battery system 11 has a battery module 4 and a BMU (Battery Management Unit) 3.

[0021] The battery module 4 has a plurality of battery cells 1 (one example of a battery) and a CMU 2. The battery cell 1 is a power storage function section capable of charge and discharge.

[0022] The CMU 2 is one example of a detection section that detects a battery voltage (hereinafter, referred to as a terminal voltage) applied to each of the plurality of battery cells 1, a battery temperature of the battery cell 1, and the like. Then, the CMU 2 outputs the terminal voltage, the battery temperature, and the like of each of the plurality of battery cells 1 to the BMU 3.

[0023] The BMU 3 monitors and protects the entire battery system 11. In the present embodiment, the BMU 3 monitors an input current flowing in the battery system 11, a cell voltage, and a temperature of each battery module 4, and performs protection of the battery system 11 at the time of abnormality detection. In addition, in the present embodiment, the BMU 3 outputs various information such as the terminal voltage and the battery temperature detected by the CMU 2, and an input current flowing from an external power source to the battery system 11 to the battery control device 10.

[0024] Here, the input current flowing from the external power source to the battery system 11 includes a current that reaches a rated current after a lapse of an arbitrary time from the start of supply of the current to the battery system 11, and then maintains (continues) the rated current constant.

[0025] The battery control device 10 (one example of an internal resistance calculation device) is a device that controls the entire battery control system using various information input from the BMU 3.

[0026] Figure 2 is a block diagram showing one example of a functional configuration of the battery control device of the first embodiment. Next, the functional configuration of the battery control device 10 of the present embodiment will be described using Figure 2 The functional configuration of the battery control device 10 of the present embodiment will be described.

[0027] In the present embodiment, as shown in Figure 2 , the battery control device 10 has a current acquisition section 12, a voltage acquisition section 13, a charge amount calculation section 14, an internal resistance calculation section 15, a display control section 16, and a display device 17.

[0028] The current acquisition section 12 acquires a cell current (one example of a battery current) flowing in the battery cell 1. In the present embodiment, the current acquisition section 12 calculates (acquires) a value obtained by dividing the input current output from the BMU 3 by the number of the plurality of battery modules 4 connected in parallel with each other, as the cell current flowing in the battery cell 1.

[0029] The voltage acquisition section 13 acquires the terminal voltage output from the BMU 3 (i.e., the terminal voltage applied to the battery cell 1).

[0030] The charge amount calculation section 14 integrates the cell current acquired by the current acquisition section 12 with respect to time, and calculates the amount of charge moved to the battery cell 1. Here, in the calculation of the charge amount, it is preferable to implement at a predetermined timing such as at the start from the no-load state or after a prescribed operation is performed.

[0031] The internal resistance calculation section 15 calculates the internal resistance of the battery cell 1 based on the amount of change in the cell current and the terminal voltage each of which is above a prescribed threshold value until the charge amount calculated by the charge amount calculation section 14. Thereby, even in the case where the input current flowing in the battery system 11 is not a pulse current at the time of calculating the internal resistance of the battery cell 1, it is possible to calculate the internal resistance of the battery cell 1 with high accuracy using the charge amount obtained by integrating the cell current flowing in the battery cell 1 with respect to time as an index.

[0032] Here, the prescribed threshold value is a threshold value set in advance. In the present embodiment, the prescribed threshold value is the amount of charge moved to the battery cell 1 in the case where the rated pulse current is flowed to the battery cell 1 for a predetermined time (for example, 10 s).

[0033] The display control section 16 generates degradation information indicating the degradation state of the battery cell 1 based on the calculation result of the internal resistance of the battery cell 1 by the internal resistance calculation section 15, and causes the generated degradation information to be displayed on the display device 17. Here, the degradation information can be the rate of the internal resistance of the battery cell 1 calculated by the internal resistance calculation section 15 with respect to the internal resistance of the battery cell 1 which is not degraded. In addition, the degradation information is information indicating the degree of degradation of the battery cell 1 (for example, "green" in the case where the battery cell 1 is not degraded, "yellow" in the case where the battery cell 1 is degraded but can be used, and "red" in the case where the battery cell 1 is degraded and cannot be used).

[0034] Figure 3 is a diagram for explaining an example of the calculation processing of the internal resistance in the case where the input current flowing in the battery system is the rated pulse current. Figure 4 is a diagram for explaining an example of the calculation processing of the internal resistance in the case where the input current flowing in the battery system is the lamp current. In Figure 3 and Figure 4 , the vertical axis indicates the cell current It and the terminal voltage Vt flowing in the battery cell 1, and the horizontal axis indicates the time t.

[0035] Next, using Figure 3 and Figure 4An example of the internal resistance calculation process will be described for each of the cases where the input current flowing through the battery system 11 is a rated pulse current and the case where the input current flowing through the battery system 11 is a lamp current.

[0036] like Figure 3 As shown, to accurately calculate the internal resistance R (Ω) of the battery cell 1, the terminal voltage Vt (= V0) and cell current It (= I0) of the battery cell 1 in the no-load state are measured, as well as the terminal voltage Vt (= Vn) and cell current It (= In) of the battery cell 1 after a predetermined time t (e.g., 10 seconds) has passed since the rated pulse current, or input current, began flowing into the battery system 11 in the no-load state. Here, the no-load state of the battery cell 1 refers to a state in which the cell current It does not flow through the battery cell 1. Furthermore, the no-load state of the battery cell 1 preferably occurs when the terminal voltage Vt applied to the battery cell 1 and the temperature of the battery cell 1 are constant.

[0037] Next, the ratio ΔV / ΔI, the voltage change ΔV (= Vn - V0) of the change in terminal voltage Vt, to the current change ΔI (= In - I0) of the change in cell current It, is calculated as the internal resistance R of the battery cell 1. According to the standard (JEVSD714), the internal resistance R calculated from the terminal voltage Vt and cell current It when a pulse current flows through the battery cell 1 for 10 seconds is a general indicator of battery performance. As degradation of the battery cell 1 progresses, the internal resistance R increases. Therefore, by tracking the change in internal resistance R over time, the degradation state of the battery cell 1 can be diagnosed.

[0038] However, this method for calculating internal resistance R presupposes the use of a controllable DC power supply to flow a cell current It into the battery cell 1. Therefore, this cell current It must be a pulse current. Furthermore, it is necessary to calculate internal resistance R while maintaining the battery cell 1 in the battery system 11 to diagnose the degradation state of the battery cell 1. In this case, if the battery system 11 operates in a manner where a pulse current continuously flows for a predetermined time t into the battery cell 1 in a no-load state, while internal resistance R can be calculated, depending on the operation of the battery system 11 or device limitations, pulse current may not flow into the battery cell 1, making accurate calculation of internal resistance R difficult.

[0039] Specifically, if Figure 4As shown, the charge amount flowing into the battery cell 1 is reduced until the predetermined time t elapses from when the cell current It flowing in the battery cell 1 starts to flow into the battery cell 1 in the case where the cell current It flowing in the battery cell 1 is the lamp current reaching the rated current at a certain constant slope. Therefore, in the case where the ratio AV / ΔI of the voltage change AV(=Vn-V0) and the current change ΔI(=In-I0) is calculated as the internal resistance R of the battery cell 1, the internal resistance R can have an error compared to the case where the cell current It flowing in the battery cell 1 is the pulse current.

[0040] Therefore, in the present embodiment, as described above, the internal resistance calculating section 15 calculates the internal resistance R of the battery cell 1 based on the change amounts of the cell current It and the terminal voltage Vt each time the charge amount calculated by integrating the cell current It flowing in the battery cell 1 with respect to time becomes equal to or greater than a predetermined threshold value.

[0041] Figure 5 and Figure 6 is a graph for explaining an example of the calculation processing of the internal resistance of the battery cell in the storage battery control device of the first embodiment. In Figure 5 and Figure 6 , the vertical axis represents the cell current It flowing in the battery cell 1 and the terminal voltage Vt, and the horizontal axis represents the time t.

[0042] Next, an example of the calculation processing of the internal resistance R in the storage battery control device 10 of the present embodiment will be described using Figure 5 and Figure 6 .

[0043] As shown in Figure 5 , the internal resistance calculating section 15 sets the charge amount Qn flowing into the battery cell 1 to a predetermined threshold value in the case where the cell current It flowing in the battery cell 1 is the rated pulse current, from the time t(=0) when the battery cell 1 is in the no-load state to the time t(=n) when the predetermined time n elapses after the cell current It starts to flow into the battery cell 1.

[0044] Then, as shown in Figure 6 , in the case where the cell current It flowing in the battery cell 1 is the lamp current, the internal resistance calculating section 15 calculates the internal resistance R of the battery cell 1 based on the current change ΔI and the voltage change AV from the time t(=0) when the battery cell 1 is in the no-load state to the time t(=m) when the charge amount Qm calculated by the charge amount calculating section 14 reaches the charge amount Qn (predetermined threshold value Qn) as the cell current It starts to flow into the battery cell 1.

[0045] Thus, the internal resistance of the battery cell 1 can be calculated based on the amount of charge that flows into the battery cell 1 in the case where the rated pulse current for the time t (= n) set in advance flows into the battery cell 1, the current variation ΔI in the case where it flows into the battery cell 1, and the voltage variation ΔV. As a result thereof, even in the case where the input current flowing in the battery system 11 is not a pulse current at the time of calculating the internal resistance of the battery cell 1, the amount of charge obtained by integrating the cell current flowing in the battery cell 1 with respect to time can be used as an index, and the internal resistance of the battery cell 1 can be calculated with high accuracy.

[0046] Figure 7 is a flowchart showing an example of the flow of the calculation processing of the internal resistance in the battery control device of the first embodiment. Next, the flow of the calculation processing of the internal resistance in the battery control device 10 of the first embodiment will be described using Figure 7 The flow of the calculation processing of the internal resistance in the battery control device 10 of the first embodiment will be described.

[0047] The current acquisition unit 12 acquires the cell current It (= I0) of the battery cell 1 at a certain time t (= 0) set in advance (step S701). In addition, the voltage acquisition unit 13 acquires the terminal voltage Vt (= V0) of the battery cell 1 at the time t (= 0) (step S701). Further, the amount of charge calculation unit 14 sets the amount of charge Qt moved to the battery cell 1 to 0 (step S701).

[0048] Next, the current acquisition unit 12 advances the time t by the sampling period Ts (for example, 0.12 s) of the cell current It, and acquires the cell current It (step S702). In addition, the voltage acquisition unit 13 also advances the time t by the sampling period Ts, and acquires the terminal voltage Vt (step S702).

[0049] The amount of charge calculation unit 14 multiplies the acquired cell current It by the sampling period Ts each time the cell current It is acquired, and calculates the amount of charge variation ΔQt. Then, the amount of charge calculation unit 14 adds the calculated amount of charge variation ΔQt to the amount of charge Qt, and calculates a new amount of charge Qt obtained by integrating the cell current It with respect to time (step S703).

[0050] The internal resistance calculation unit 15 judges whether or not the amount of charge Qt becomes equal to or greater than a prescribed threshold value Qn each time the new amount of charge Qt is calculated (step S704). In the case where the amount of charge Qt is judged to be lower than the prescribed threshold value Qn (step S704: No), the processing returns to step S702.

[0051] On the other hand, in a case where it is determined that the charge amount Qt is equal to or higher than the prescribed threshold value Qn (step S704: YES), the internal resistance calculating section 15 determines the time t (=m) at which the charge amount Qt becomes equal to or higher than the prescribed threshold value Qn, and acquires the terminal voltage Vt (=Vm) and the cell current It (=Im) at the determined time m (step S705).

[0052] Next, the internal resistance calculating section 15 determines whether the time m is equal to or higher than a prescribed time (step S706). Here, the prescribed time is a time set in advance, and is, for example, 60 s. Then, in a case where the time m is equal to or higher than the prescribed time, the internal resistance calculating section 15 does not perform the calculation of the internal resistance of the battery cell 1.

[0053] That is, the internal resistance calculating section 15 is configured to, in a case where the elapsed time from the start of the flow of the cell current into the battery cell 1 to the time at which the charge amount Qt becomes equal to or higher than the prescribed threshold value is equal to or higher than the prescribed time, not perform the calculation of the internal resistance of the battery cell 1. Alternatively, the internal resistance calculating section 15 is configured to, in a case where the elapsed time from the start of the flow of the cell current into the battery cell 1 to the time at which the charge amount Qt becomes equal to or higher than the prescribed threshold value is equal to or higher than the prescribed time, discard the calculation result of the internal resistance of the battery cell 1. Thus, in a case where the time taken for the charge amount Qt flowing in the battery cell 1 to reach the prescribed threshold value is long, or the calculation accuracy of the internal resistance of the battery cell 1 is reduced due to a change in the temperature of the battery cell 1 or the like, the calculation of the internal resistance of the battery cell 1 is not performed, and thus the calculation accuracy of the internal resistance of the battery cell 1 can be improved.

[0054] On the other hand, in a case where the time m is lower than the prescribed time, the internal resistance calculating section 15 calculates the ratio AV / ΔI of the voltage change AV (=Vm-V0) and the current change ΔI (=Im-I0) as the internal resistance R using the cell current I0 and the terminal voltage V0 of the battery cell 1 at the time t (=0), and the cell current Im and the terminal voltage Vm of the battery cell 1 at the time m (step S707).

[0055] Thus, according to the storage battery control device 10 of the first embodiment, even in a case where the input current flowing in the battery system 11 is not a pulse current at the time of the calculation of the internal resistance of the battery cell 1, the charge amount obtained by integrating the cell current flowing in the battery cell 1 with respect to time can be used as an index, and the internal resistance of the battery cell 1 can be calculated with high accuracy.

[0056] In the present embodiment, the battery control device 10 acquires the cell current and the terminal voltage of the battery cell 1, and calculates the internal resistance of the battery cell 1 using the acquired cell current and terminal voltage, but can calculate the internal resistance of the battery module 4 or each battery cell using the cell current and the terminal voltage of the battery module 4 or each battery cell in which a plurality of battery cells 1 are connected in series or in parallel.

[0057] (Second Embodiment)

[0058] The present embodiment is an example in which the temperature of the battery cell is acquired, and the result of the calculation of the internal resistance of the battery cell is corrected based on the acquired temperature of the battery cell. In the following description, the same configuration as the first embodiment is omitted.

[0059] Figure 8 is a block diagram showing an example of the functional configuration of the battery control device of the second embodiment. In the present embodiment, the battery control device 800 has a temperature acquisition section 21 and an internal resistance temperature correction section 22 in addition to the current acquisition section 12, the voltage acquisition section 13, the charge amount calculation section 14, the internal resistance calculation section 15, the display control section 16, and the display device 17.

[0060] The temperature acquisition section 21 acquires the battery temperature of the battery cell 1 output from the BMU 3.

[0061] The internal resistance temperature correction section 22 is an example of a correction section that corrects the internal resistance of the battery cell 1 calculated by the internal resistance calculation section 15 based on the battery temperature of the battery cell 1 acquired by the temperature acquisition section 21. Specifically, the internal resistance temperature correction section 22 normalizes the result of the calculation of the internal resistance of the battery cell 1 with respect to a predetermined battery temperature (for example, 25°C) based on the battery temperature of the battery cell 1. Thereby, it is possible to exclude the influence of the temperature characteristics of the internal resistance of the battery cell 1, and thus it is possible to track the aging of the internal resistance due to the deterioration of the battery cell 1.

[0062] The battery cell 1 has a temperature characteristic in which the internal resistance thereof becomes larger when the battery temperature of the battery cell 1 is low, and the internal resistance thereof becomes smaller when the battery temperature of the battery cell 1 is high. Therefore, in the case of diagnosing the deterioration state of the battery cell 1 while tracking the aging of the internal resistance of the battery cell 1, it is possible to diagnose the deterioration state of the battery cell 1 without considering the temperature characteristics of the battery cell 1 as long as the internal resistance of the battery cell 1 is calculated in a state where the battery temperature is the same.

[0063] However, in a battery, such as the battery cell 1 mounted on a vehicle, whose battery temperature is not constant due to external air temperature, surrounding heat sources, and the like, the battery temperature at the time of detection of a measured value, such as the cell current, used in the calculation of the internal resistance differs, and even if the aging of the internal resistance of the battery is tracked, it is difficult to determine whether the internal resistance has become large due to deterioration or the internal resistance has become large due to a decrease in the battery temperature.

[0064] Therefore, in the present embodiment, as described above, the internal resistance temperature correction unit 22 corrects the internal resistance of the battery cell 1 calculated by the internal resistance calculation unit 15 on the basis of the battery temperature of the battery cell 1 acquired by the temperature acquisition unit 21. For example, the internal resistance temperature correction unit 22 refers to a correction table to determine a correction value of the internal resistance corresponding to the acquired battery temperature of the battery cell 1. Here, the correction table is a table in which the battery temperature of the battery cell 1 and the correction value of the internal resistance found through a characteristic test of the battery cell 1 or the like are associated with each other. Then, the internal resistance temperature correction unit 22 corrects the calculation result of the internal resistance by the internal resistance calculation unit 15 using the determined correction value.

[0065] Thus, according to the battery control device 800 of the second embodiment, it is possible to exclude the influence of the internal resistance of the battery cell 1 due to the temperature characteristics, and thus it is possible to track the aging of the internal resistance due to the deterioration of the battery cell 1.

[0066] (Third Embodiment)

[0067] The present embodiment is an example in which the amount of charge moved to the battery cell is calculated by integrating the cell current of the battery cell on the basis of the state in which the battery cell is in a no-load state. In the following description, the same configuration as in the first and second embodiments is omitted.

[0068] In the present embodiment, the amount of charge moved to the battery cell 1 is calculated by integrating the cell current acquired by the current acquisition unit 12 with respect to time on the basis of the state in which the battery cell 1 is in a no-load state. Thus, it is possible to suppress the influence of the cell current of the battery cell 1 on the terminal voltage of the battery cell 1 before the internal resistance of the battery cell 1 is calculated, and thus it is possible to improve the calculation accuracy of the internal resistance of the battery cell 1.

[0069] Here, the state in which the battery cell 1 is in a no-load state means a state in which the cell current flowing in the battery cell 1 is 0 A. In addition, the state in which the battery cell 1 is in a no-load state is preferably a state in which the terminal voltage and the battery temperature of the battery cell 1 are stable (for example, a state in which the terminal voltage and the battery temperature of the battery cell 1 become a predetermined terminal voltage and battery temperature) in addition to the case in which the cell current flowing in the battery cell 1 is 0 A.

[0070] In a case where the battery cell 1 is used before the internal resistance of the battery cell 1 is calculated, due to the capacitor component possessed by the battery cell 1, sometimes the terminal voltage of the battery cell 1 cannot immediately become a stable steady state. In addition, since the battery cell 1 is a heat generator, even if the cell current flowing in the battery cell 1 is 0 A, sometimes the battery temperature thereof cannot immediately become a stable steady state. In such a state, an influence is exerted on the change in the terminal voltage used when the internal resistance of the battery cell 1 is calculated, and an error is generated in the calculation result of the internal resistance of the battery cell 1.

[0071] Therefore, in the present embodiment, the charge amount calculation section 14 calculates the charge amount moved to the battery cell 1 by integrating the cell current acquired by the current acquisition section 12 with respect to time on the basis of a case where the battery cell 1 is in a no-load state.

[0072] Thus, according to the storage battery control device 10, 800 of the third embodiment, it is possible to suppress the influence of the cell current of the battery cell 1 on the terminal voltage of the battery cell 1 before the internal resistance of the battery cell 1 is calculated, and thus it is possible to improve the calculation accuracy of the internal resistance of the battery cell 1.

[0073] As explained above, according to the first to third embodiments, even in a case where the input current flowing in the battery system 11 is not a pulse current when the internal resistance of the battery cell 1 is calculated, it is possible to calculate the internal resistance of the battery cell 1 with high accuracy by using the charge amount obtained by integrating the cell current flowing in the battery cell 1 with respect to time as an index.

[0074] In addition, the program executed by the storage battery control device 10, 800 of the present embodiment is provided by being assembled in advance in a ROM (Read Only Memory) or the like. It can also be configured so that the program executed by the storage battery control device 10, 800 of the present embodiment is provided as a file in a form that can be installed or in a form that can be executed, in a recording medium that can be read by a computer, such as a CD-ROM, a floppy disk (FD), a CD-R, a DVD (Digital Versatile Disk), or the like.

[0075] Furthermore, it can also be configured so that the program executed by the storage battery control device 10, 800 of the present embodiment is stored on a computer connected to a network such as the Internet, and is provided by being downloaded via the network. In addition, it can also be configured so that the program executed by the storage battery control device 10, 800 of the present embodiment is provided or distributed via a network such as the Internet.

[0076] The program executed by the battery control device 10, 800 of the present embodiment can also be configured as a module including the above-described components (the current acquisition section 12, the voltage acquisition section 13, the charge amount calculation section 14, the internal resistance calculation section 15, the temperature acquisition section 21, the internal resistance temperature correction section 22, and the display control section 16). As actual hardware, a CPU (Central Processing Unit) as an example of a processor reads out the program from the above-described ROM and executes it, whereby the above-described components are loaded on a main storage device, and the current acquisition section 12, the voltage acquisition section 13, the charge amount calculation section 14, the internal resistance calculation section 15, the temperature acquisition section 21, the internal resistance temperature correction section 22, and the display control section 16 are generated on the main storage device.

[0077] The several embodiments of the present application have been described, but these embodiments are presented as examples and are not intended to limit the scope of the application. These new embodiments can be implemented in other various ways, and various omissions, substitutions, and changes can be made within the scope of the gist of the application. These embodiments and modifications thereof are included in the scope, gist of the application, and in the scope of the application and equivalents thereof recited in the claims.

Claims

1. An internal resistance calculating device comprising: a current acquisition section that acquires a battery current flowing in a battery; a voltage acquisition section that acquires a battery voltage applied to the battery; a charge amount calculation section that calculates a charge amount moved to the battery by integrating the battery current acquired by the current acquisition section with respect to time; and an internal resistance calculation section that determines whether the charge amount calculated by the charge amount calculation section becomes a threshold value or more, and calculates an internal resistance of the battery based on a change amount of each of the battery current and the battery voltage with respect to an elapsed time until the charge amount becomes the threshold value or more, when the charge amount becomes the threshold value or more.

2. The internal resistance calculating device according to claim 1, further comprising: a temperature acquisition section that acquires a temperature of the battery; and a correction section that corrects the internal resistance calculated by the internal resistance calculation section based on the temperature of the battery acquired by the temperature acquisition section.

3. The internal resistance calculation device according to claim 1 or 2, wherein The internal resistance calculation section discards a calculation result of the internal resistance when an elapsed time until the charge amount becomes the threshold value or more with respect to a current flowing in the battery is a predetermined time or more.

4. The internal resistance calculating device according to claim 1 or 2, wherein The charge amount calculation section calculates the charge amount based on a case where the battery is in a no-load state.

5. A battery control system comprising: a battery; an acquisition section that acquires a battery current flowing in the battery; a detection section that detects a battery voltage applied to the battery; a charge amount calculation section that calculates a charge amount moved to the battery by integrating the battery current acquired by the acquisition section with respect to time; and an internal resistance calculation section that determines whether the charge amount calculated by the charge amount calculation section becomes a threshold value or more, and calculates an internal resistance of the battery based on a change amount of each of the battery current and the battery voltage with respect to an elapsed time until the charge amount becomes the threshold value or more, when the charge amount becomes the threshold value or more.

6. An internal resistance calculation method executed by an internal resistance calculation device, comprising: An acquisition step of a battery current flowing in a battery; an acquisition step of a battery voltage applied to the battery; a calculation step of a charge amount moved to the battery by integrating the battery current with respect to time; and a calculation step of an internal resistance of the battery based on a change amount of each of the battery current and the battery voltage with respect to an elapsed time until the charge amount becomes a threshold value or more, when the charge amount becomes the threshold value or more.

7. The internal resistance calculating method according to claim 6, further comprising: an acquisition step of a temperature of the battery; and a correction step of the internal resistance based on the temperature of the battery.

8. The internal resistance calculation method according to claim 6 or 7, wherein The calculation step of the internal resistance of the battery includes a step of discarding a calculation result of the internal resistance when an elapsed time until the charge amount becomes the threshold value or more with respect to a current flowing in the battery is a predetermined time or more.

9. The internal resistance calculation method according to claim 6 or 7, wherein The calculation step of the charge amount is performed based on a case where the battery is in a no-load state.

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