Method for determining actual capacity of battery, vehicle and storage medium

Abstract

The invention provides a method for determining the actual capacity of a battery, a vehicle and a storage medium, the method is applied to the field of vehicles, and the method comprises the steps that the rated capacity of a battery pack on the vehicle and the charge state value of each single battery in the battery pack are acquired, the minimum charge state value is determined, and the battery pack comprises one or more single batteries; after the battery pack is subjected to open-circuit voltage correction, determining the total absorbed electric quantity and the total released electric quantity of the battery pack in the charging process until the battery pack is fully charged by taking the current electric quantity as a starting point; determining an electric quantity difference value according to the total absorbed electric quantity and the total released electric quantity; and determining the actual capacity of the battery pack based on the rated capacity, the minimum state-of-charge value and the electric quantity difference value. According to the method, the actual capacity of the battery pack can be determined based on the minimum state-of-charge value, the rated capacity and the electric quantity difference value of the single battery after the battery pack is subjected to open-circuit voltage correction, so that the accuracy of determining the actual capacity of the battery is improved.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and more specifically, to a method for determining actual battery capacity, a vehicle and a storage medium in the field of vehicles. Background Art

[0002] As time goes by, the charging and discharging of the battery will cause the battery parameters to be inaccurate. If the battery parameters are not calibrated, the health of the battery cannot be monitored.

[0003] In the related art, the health status of the battery is estimated by determining the rated capacity of the battery when it leaves the factory and the accumulated power during the charging and discharging process. However, there may be errors in the measurement of the accumulated power during the charging and discharging process of the battery, resulting in inaccurate estimated battery capacity. Summary of the invention

[0004] The present application provides a method, a vehicle and a storage medium for determining the actual capacity of a battery. The method can determine the actual capacity of a battery pack based on the minimum state of charge value, the rated capacity and the power difference of each single cell after the open circuit voltage of the battery pack has been corrected, thereby improving the accuracy of determining the actual capacity of the battery.

[0005] In a first aspect, a method for determining an actual capacity of a battery is provided, the method comprising:

[0006] Obtaining the rated capacity of a battery pack on the vehicle and the state of charge value of each single battery in the battery pack, and determining a minimum state of charge value, the battery pack including one or more single batteries;

[0007] After the open circuit voltage of the battery pack is corrected, the total power absorbed and the total power released by the battery pack during the charging process until the battery pack is fully charged are determined with the current power as the starting point, wherein the total power released includes the power released by the battery pack during self-discharge and the power released by the battery pack during use;

[0008] Determine the power difference based on the total power absorbed and the total power released;

[0009] Based on the rated capacity, the minimum state of charge value and the charge difference value, the actual capacity of the battery pack is determined.

[0010] Through the above technical solution, the rated capacity of the battery pack on the vehicle and the state of charge value of each single cell in the battery pack are obtained, and the minimum state of charge value is determined. The battery pack includes one or more single cells. There is an error in the minimum state of charge value obtained. In order to reduce the error of the state of charge value, after the battery pack is corrected for open circuit voltage, the total amount of electricity absorbed and the total amount of electricity released by the battery pack during the charging process until it is fully charged are determined with the current electricity as the starting point. The electricity difference is determined based on the total amount of electricity absorbed and the total amount of electricity released. Based on the rated capacity, the minimum state of charge value and the electricity difference, the actual capacity of the battery can be determined. Since the rated capacity of the battery pack is used to indicate the maximum electrical energy storage capacity of the battery and the minimum state of charge value of the single cell can monitor the minimum remaining capacity of the battery pack, the actual capacity of the battery pack can be re-determined based on the minimum state of charge value, the rated capacity and the electricity difference, thereby improving the accuracy of determining the actual capacity of the battery.

[0011] In combination with the first aspect, in some possible implementations, the actual rated capacity of the battery pack is determined according to the product of the rated capacity and the minimum state of charge value;

[0012] Determine the actual capacity based on the difference between the actual rated capacity and the power.

[0013] In combination with the first aspect, in some possible implementations, after the open circuit voltage of the battery pack is corrected, the mileage and charging information of the vehicle are obtained;

[0014] Based on the mileage and charging information, determining whether preset conditions for determining the actual capacity of the battery pack are met;

[0015] When the preset conditions are met, the actual capacity of the battery pack is determined.

[0016] In conjunction with the first aspect, in certain possible implementations, the preset condition is satisfied when the driving mileage is less than or equal to a first preset value, the charging time interval of the vehicle is less than or equal to a second preset value, and the battery pack has not undergone additional correction;

[0017] When the driving mileage is greater than a first preset value, and / or the charging time interval of the vehicle is greater than a second preset value, and / or the battery pack undergoes additional correction, the preset condition is not satisfied.

[0018] In combination with the first aspect, in some possible implementations, open circuit voltage correction is performed on the battery pack.

[0019] In combination with the first aspect, in some possible implementations, when the temperature of the battery pack is less than or equal to a third preset value and the current of the battery pack is less than or equal to a fourth preset value, measuring the open circuit voltage of the battery pack;

[0020] In the correspondence table between the open circuit voltage and the state of charge value, searching for the reference state of charge value of each single battery in the battery pack corresponding to the open circuit voltage;

[0021] When the reference state of charge value of each single cell does not match the state of charge value of each single cell in the battery pack, the state of charge value of each single cell in the battery pack is corrected to the reference state of charge value of each single cell.

[0022] In combination with the first aspect, in some possible implementations, the health status of the battery pack is evaluated based on the actual capacity and the rated capacity.

[0023] In conjunction with the first aspect, in some possible implementations, determining a ratio of the actual capacity to the rated capacity;

[0024] When the ratio is greater than or equal to a fifth preset value, determining that the health status of the battery pack is healthy;

[0025] When the ratio is less than a fifth preset value, it is determined that the health condition of the battery pack is unhealthy.

[0026] In a second aspect, a vehicle is provided, comprising a memory and a processor. The memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, so that the vehicle executes the method executed by the above method for determining the actual capacity of a battery.

[0027] In a third aspect, a computer program product is provided, which includes: a computer program code, which, when executed on a computer, enables the computer to execute the method executed by the above-mentioned method for determining the actual capacity of a battery.

[0028] In a fourth aspect, a computer-readable storage medium is provided, which stores a computer program code. When the computer program code is run on a computer, the computer executes the method executed by the above-mentioned method for determining the actual capacity of a battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of an implementation environment of a method for determining an actual capacity of a battery provided in an embodiment of the present application;

[0030] Figure 2 is a schematic flow chart of a method for determining the actual capacity of a battery provided in an embodiment of the present application;

[0031] Figure 3 is a schematic flow chart of a method for evaluating the health status of a battery pack provided in an embodiment of the present application;

[0032] Figure 4is a schematic diagram of the structure of a device for determining the actual capacity of a battery provided in an embodiment of the present application;

[0033] Figure 5 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0035] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0036] With the continuous development of new energy technologies, more and more people choose new energy vehicles as their daily travel vehicles. Among them, battery packs are indispensable components of new energy vehicles. However, battery packs are easily affected by various factors such as temperature, internal resistance loss, and heat loss during use, resulting in a continuous decline in battery performance. Therefore, during the use of battery packs, it is necessary to determine the actual capacity of the battery pack to avoid unnecessary losses to users.

[0037] In order to solve the problems in the related art, the embodiments of the present application provide a method for determining the actual capacity of a battery, which are described in detail below. It should be noted that the description order of the following embodiments is not intended to limit the preferred order of the embodiments.

[0038] Figure 1 It is a schematic diagram of an implementation environment of a method for determining an actual battery capacity provided in an embodiment of the present application.

[0039] For example, Figure 1 As shown, the implementation environment includes a vehicle control unit (Engine Control Unit, ECU) 101 and a battery management system 102 .

[0040] The vehicle control unit 101 is an important control unit of the vehicle, which can obtain relevant data of the vehicle and control the vehicle to perform corresponding operations based on the relevant data, for example, obtain the battery status parameters of the vehicle and control the battery charging and discharging of the vehicle based on the battery status parameters. In some embodiments, the vehicle control unit 101 can send driving parameters to the battery management system 102 so that the battery management system 102 can implement battery management based on the driving parameters.

[0041] The battery management system 102 is a system for monitoring and managing the battery operating status, which can detect the battery status parameters of the vehicle and implement various battery management functions based on the battery status parameters. In some embodiments, the battery management system 102 sends the battery status parameters of the vehicle to the vehicle control unit 101, so that the vehicle control unit 101 controls the vehicle to perform corresponding operations based on the battery status parameters.

[0042] Figure 2 It is a schematic flow chart of a method for determining the actual capacity of a battery provided in an embodiment of the present application.

[0043] For example, Figure 2 As shown, the execution subject of the method is a vehicle control unit, and the method 200 includes:

[0044] Step 201 , obtaining the rated capacity of a battery pack on a vehicle and the state of charge value of each single cell in the battery pack, and determining a minimum state of charge value, wherein the battery pack includes one or more single cells.

[0045] It should be understood that multiple single cells are combined in series or in parallel to obtain a battery pack for a vehicle. If a single cell in the battery pack fails, the single cell can be processed, reducing the cost of processing the failure. For example, if a single cell overheats or has an internal short circuit, the single cell can be replaced without replacing the entire battery pack, reducing the loss of the battery pack.

[0046] Among them, the battery pack is a collection of multiple single cells. The battery pack of a vehicle is used to store and provide electrical energy. For example, the battery pack can provide power for the vehicle to drive the vehicle. The rated capacity of the battery pack is the maximum capacity of the battery pack to store electrical energy. The rated capacity is used to describe the amount of electrical energy stored and released by the battery pack.

[0047] The state of charge (SOC) of a single cell is the ratio of the current remaining power of the single cell to the power when it is fully charged. The state of charge value is usually expressed as a percentage, ranging from 0% (fully discharged) to 100% (fully charged).

[0048] Among them, the minimum state of charge value of the single battery can monitor the discharge capacity of the battery pack.

[0049] It should be understood that the single cell provides electrical energy to the vehicle by discharging. However, when the state of charge value of the single cell drops to the minimum, the battery management system will stop discharging to prevent the single cell from over-discharging and causing battery damage. However, the state of charge value of each single cell is different, so it is necessary to determine the minimum state of charge value among the state of charge values ​​of the single cells to ensure that each single cell in the battery pack remains consistent during the discharge process, thereby preventing the battery pack from over-discharging.

[0050] For example, the state of charge value of the first single cell in the battery pack is 40%, and the state of charge value of the second single cell is 30%. If the battery pack continues to discharge, the second single cell may be over-discharged and damaged. Therefore, the smallest state of charge value among the state of charge values ​​of the single cells in the battery pack is determined to be 30% to avoid over-discharge or over-charging of the battery pack and damage to the battery.

[0051] In a possible implementation, the rated capacity of the battery pack and the state of charge value of each single battery in the battery pack are acquired based on the battery management system.

[0052] In some embodiments, the charging current and discharging current of the battery pack within a preset time period are acquired based on a current sensor; the charging current and the discharging current are integrated to obtain the charged power of the battery pack and the discharged power of the battery pack.

[0053] In some embodiments, the calculation formula of the state of charge value of each single battery is as follows.

[0054] The state of charge value of a single cell = (charge level of the battery pack + discharge level of the battery pack) / rated capacity.

[0055] It should be understood that the state of charge values ​​of single cells are different. In order to avoid over-discharge of single cells when the battery pack is discharged, it is necessary to determine the minimum state of charge value among the single cells to ensure that each single cell in the battery pack does not exceed the minimum state of charge when discharged, thereby preventing the battery pack from over-discharging.

[0056] In some embodiments, a minimum state of charge value in the battery pack is determined based on the state of charge value of each battery cell in the battery pack.

[0057] For example, if the state of charge of the first single cell is 20%, the state of charge of the second single cell is 30%, and the state of charge of the third single cell is 25%, then the minimum state of charge of the single cells in the battery pack is determined to be 20%.

[0058] In this implementation, the rated capacity of the battery pack and the state of charge value of each single cell in the battery pack are acquired based on the battery management system, and the state of charge value of each single cell can be obtained, so that the battery pack can be managed based on the state of charge value.

[0059] Step 202 , after the open circuit voltage of the battery pack is corrected, the total power absorbed and the total power released by the battery pack during the charging process until the battery pack is fully charged are determined based on the current power level.

[0060] The open circuit voltage correction is used to improve the accuracy of the state of charge value of each single cell in the battery pack. When the battery pack has no external load, the voltage of the battery pack is measured to obtain the current state of charge value of the battery pack.

[0061] The total amount of electricity absorbed during the charging process is used to indicate the amount of electricity charged into the battery pack during the charging process until it is fully charged after the open circuit voltage of the battery pack is corrected. The total amount of electricity released by the vehicle includes the amount of electricity released by the battery pack during self-discharge during the charging process of the vehicle and the amount of electricity released by the battery pack during use.

[0062] It should be understood that the battery pack will self-discharge due to the gradual loss of power due to the chemical reaction inside the battery pack. In this case, even if the battery pack is being charged, the battery pack will still release power to the outside, so it is necessary to determine the power released by the battery pack during self-discharge during the charging process of the battery pack.

[0063] It should also be understood that during the charging process of the vehicle, the battery pack of the vehicle may be discharged in parallel. For example, when the vehicle is charged in winter, in order to prevent the user from freezing, the battery pack will absorb electricity to charge the vehicle while releasing electricity to heat the vehicle. In this case, taking the current electricity as the starting point, the electricity released by the battery pack when in use is determined during the charging process of the battery pack to obtain the total released electricity of the battery pack.

[0064] After the open circuit voltage of the battery pack is corrected, the state of charge value of the battery pack has been corrected, so as to obtain the accurate state of charge value of each single cell. Before charging and discharging, the battery pack may still have residual power. If the remaining power of the battery pack is not determined, it is impossible to determine when the battery pack stops charging or discharging, which may cause overcharging or over-discharging of the battery. Therefore, the current power of the battery pack should be used as the starting point to determine the total power absorbed during the charging process and the total power released during the discharging process of the battery pack, so as to avoid overcharging or over-discharging of the battery and ensure battery safety. In this case, after the open circuit voltage of the battery pack is corrected, the current power needs to be obtained.

[0065] In some embodiments, after the open circuit voltage of the battery pack is corrected, the current charge of the battery pack is obtained based on the current sensor.

[0066] For example, after the open circuit voltage of the battery pack is corrected, the current capacity of the battery pack obtained based on the current sensor is 40AH.

[0067] In some embodiments, taking the current power as the starting point, the charging current of the battery pack during the charging process and the discharging current of the battery pack when in use are obtained based on the current sensor; the charging current and the discharging current are integrated to obtain the total power absorbed and released by the battery pack.

[0068] In some embodiments, the total amount of electricity absorbed is calculated as follows.

[0069]

[0070] Among them, t 1 Indicates the time when the battery pack starts charging, t 2 Indicates the time when the battery pack ends charging, I c Indicates the charging current of the battery pack during the charging process.

[0071] For example, the charging current during the charging process is 5A, the charging process lasts for 14 hours, and the total power absorbed by the battery pack is 70 (ampere hours) AH.

[0072] In some embodiments, the calculation formula for the total amount of electricity released is as follows.

[0073]

[0074] Among them, t 1 Indicates the time when the battery pack starts discharging, t 2 Indicates the time when the battery pack ends discharging, I d Indicates the discharge current of the battery pack during the discharge process.

[0075] For another example, the current power of the battery pack is 80AH, the discharge current during the charging process is 2A, and the discharge process lasts for 20 hours, so the total released power of the battery pack is 40AH.

[0076] In this implementation, after the open circuit voltage of the battery pack is corrected, the total power absorbed and released by the battery pack during the charging process is determined based on the current power.

[0077] It should be understood that when estimating the state of charge value of a battery pack, the battery management system usually determines the state of charge value of each single cell in the battery pack based on the integral of the current of the battery pack and the time of charging and discharging the battery pack. However, when the current changes rapidly and the internal resistance of the battery changes with temperature, the current detected by the current sensor will have errors. When the battery pack is charged or discharged multiple times, the error of the measured current will be accumulated, causing the state of charge value of each single cell of the battery pack to deviate from the true value. Therefore, in order to reduce the error caused by accumulation, the open circuit voltage of the battery pack needs to be corrected.

[0078] In a possible implementation, open circuit voltage correction is performed on the battery pack.

[0079] The following is an explanation of the open circuit voltage correction of the battery pack.

[0080] In a possible implementation, when the temperature of the battery pack is less than or equal to a third preset value and the current of the battery pack is less than or equal to a fourth preset value, the open circuit voltage of the battery pack is measured; and the state of charge value of each single cell in the battery pack is corrected based on the open circuit voltage.

[0081] It should be understood that during the charging and discharging process of the battery pack, the temperature of the battery pack increases, which will increase the chemical reaction inside the battery pack, and thus affect the open circuit voltage of the battery. Therefore, it is necessary to determine whether the temperature of the battery pack is less than or equal to the third preset value. The battery pack is in an open circuit state only when the current of the battery pack is less than or equal to the fourth preset value.

[0082] Among them, the third preset value is automatically determined by the vehicle control unit, or is set by the technician according to the actual situation, and the embodiment of the present application does not limit this. For example, the third preset value can be 25 degrees Celsius. The fourth preset value is automatically determined by the vehicle control unit, or is set by the technician according to the actual situation, and the embodiment of the present application does not limit this. For example, the fourth preset value can be 0 ampere (A).

[0083] In this embodiment, the temperature of the battery pack is less than or equal to the third preset value and the current of the battery pack is less than or equal to the fourth preset value, indicating that the chemical reaction inside the battery pack has reached equilibrium. In this case, the ambient temperature of the battery pack is ensured to be relatively stable, and the open circuit voltage of the battery pack is measured to obtain a more accurate open circuit voltage. The state of charge value of each single cell in the battery pack is corrected based on the open circuit voltage, thereby reducing the error of the state of charge value of each single cell.

[0084] In order to explain the above implementation more clearly, the above implementation is explained in several parts below.

[0085] The first part describes the content of measuring the open circuit voltage of the battery pack when the temperature of the battery pack is less than or equal to the third preset value and the current of the battery pack is less than or equal to the fourth preset value.

[0086] In some embodiments, the power input and the load output of the battery pack are disconnected, so that the battery pack is in an open circuit state.

[0087] It should be understood that when the power input and load output of the battery pack are disconnected, there is no current in the battery pack. Since the battery pack undergoes chemical reactions during the charging and discharging process, the temperature in the battery pack is relatively high. To avoid inaccurate open circuit voltage measurement due to temperature, the battery is left to rest for a preset time so that the chemical reaction inside the battery pack reaches a balanced state.

[0088] In some embodiments, after the battery pack is charged and discharged, the temperature of the battery pack is compensated based on the battery thermal management system so that the temperature of the battery pack is less than or equal to a third preset value.

[0089] Among them, the battery thermal management system is used to effectively control the temperature of the battery pack during the charging and discharging process to ensure the safety of the battery pack and extend its service life.

[0090] For example, coolant channels are arranged in the battery pack to remove heat generated by the batteries through the coolant, thereby regulating the temperature in the battery pack.

[0091] In some embodiments, when the temperature of the battery pack is less than or equal to a third preset value and the current of the battery pack is less than or equal to a fourth preset value, the open circuit voltage of the battery pack is acquired based on the voltage sensor.

[0092] The voltage sensor is connected to the positive and negative electrodes of the battery pack. In this case, the open circuit voltage of the battery pack can be obtained based on the voltage sensor.

[0093] In this embodiment, since the temperature of the battery pack is less than or equal to the third preset value and the current of the battery pack is less than or equal to the fourth preset value, in this case, the ambient temperature of the battery pack is relatively stable and the battery pack is in an open circuit state, so the open circuit voltage of the battery pack is measured with higher accuracy.

[0094] The second part describes the content of correcting the state of charge value of each single battery in the battery pack based on the open circuit voltage.

[0095] In a possible implementation, in a correspondence table between open circuit voltage and state of charge value, a reference state of charge value of each single cell in the battery pack corresponding to the open circuit voltage is searched; when the reference state of charge value of each single cell does not match the state of charge value of each single cell in the battery pack, the state of charge value of each single cell in the battery pack is corrected to the reference state of charge value of each single cell.

[0096] The open circuit voltage and state of charge value correspondence table is a relationship table preset when the battery pack leaves the factory. For example, the battery manufacturer provides corresponding curve data of the open circuit voltage and state of charge value.

[0097] In some embodiments, after the open circuit voltage of each single cell in the battery pack is determined, a reference state of charge value corresponding to the open circuit voltage of each single cell is searched in a correspondence table between open circuit voltage and state of charge value.

[0098] For example, based on the open circuit voltage of each single cell, it is found that the reference state of charge value of the first single cell is 20%, the reference state of charge value of the second single cell is 30%, and the reference state of charge value of the third single cell is 25%.

[0099] It should be understood that after the battery pack is charged and discharged, the charge state value of each single cell in the battery pack may not match the reference charge state value in the corresponding relationship table. Therefore, the charge state value of each single cell in the battery pack is corrected to the reference charge state value of each single cell, so that the charge state value of each single cell in the battery pack is closer to the actual value.

[0100] For example, if the reference state of charge value of the first single cell is 20%, the reference state of charge value of the second single cell is 30%, and the reference state of charge value of the third single cell is 25%; the state of charge value of the first single cell is 40%, the state of charge value of the second single cell is 35%, and the reference state of charge value of the third single cell is 30%. Therefore, if it is determined that the reference state of charge value of each single cell does not match the state of charge value of each single cell in the battery pack, the state of charge value of the first single cell is corrected to 20%, the state of charge value of the second single cell is corrected to 30%, and the state of charge value of the third single cell is corrected to 25%, so that the state of charge value of each single cell in the battery pack is more accurate.

[0101] Step 203, determining the power difference according to the total power absorbed and the total power released.

[0102] The power difference is used to describe the actual charged capacity of the battery pack.

[0103] It should be understood that the battery pack will absorb electricity during the charging process. The battery pack may also use the battery pack during the charging process, so it is possible to determine the actual amount of electricity charged into the battery pack based on the difference between the total amount of electricity absorbed and the total amount of electricity released by the battery pack.

[0104] In some embodiments, the formula for determining the power difference based on the total power absorbed and the total power released is as follows.

[0105] Power difference = total power absorbed - total power released

[0106] Among them, the charge difference is used to evaluate the actual capacity of the battery; the total power absorbed is the total power absorbed by the battery pack during the charging process until it is fully charged; the total power released includes the power released by the battery pack during self-discharge and the power released when the battery pack is in use.

[0107] For example, if the total power absorbed by the battery pack is 70AH and the total power released by the battery pack is 5AH, the power difference is 65AH.

[0108] In this case, the difference between the total power absorbed and the total power released is determined. The power difference can describe the actual amount of power charged into the battery. Based on the actual amount of power charged, the actual capacity of the battery can be evaluated, thereby optimizing the strategy of the battery management system, improving user experience and system reliability, and ensuring safety.

[0109] Step 204 , determining the actual capacity of the battery pack based on the rated capacity, the minimum state of charge value and the power difference value.

[0110] The actual capacity of the battery pack is used to indicate the amount of electricity that the battery pack can provide during actual use.

[0111] It should be understood that the rated capacity is usually used to indicate the theoretical maximum capacity of a battery pack. However, in actual applications, as the battery pack is used, the chemical composition inside the battery pack changes. The reduction of active materials inside the battery pack will cause the battery pack's ability to store electrical energy to weaken, thus causing the actual capacity of the battery to decrease. However, if the actual capacity of the battery pack cannot be accurately obtained, it may cause the battery to be incorrectly charged and discharged, thereby accelerating battery aging, so the actual capacity of the battery pack needs to be re-determined.

[0112] In a possible implementation manner, the actual rated capacity of the battery pack is determined according to the product of the rated capacity and the minimum state of charge value; and the actual capacity is determined according to the actual rated capacity and the power difference.

[0113] The actual rated capacity is used to indicate the remaining capacity of the battery pack in actual applications, and the power difference is used to indicate the total power actually charged into the battery pack.

[0114] It should be understood that since the minimum state of charge value can monitor the discharge capacity of the battery pack, that is, during the discharge of the battery pack, the total amount of electricity released by the battery pack must be less than or equal to the minimum state of charge value, the actual rated capacity of the battery pack can be determined based on the product of the rated capacity and the minimum state of charge value.

[0115] For example, if the rated capacity of the battery pack is 100AH, and the minimum state of charge of the single battery in the battery pack is 30%, then the actual rated capacity of the battery pack is 30AH. That is, the actual remaining power of the single battery in the battery pack is 30AH.

[0116] In some embodiments, the calculation formula for determining the actual capacity is as follows.

[0117] The actual capacity of the battery pack = (the minimum state of charge value of the single cell * rated capacity) + total power absorbed - total power released.

[0118] The product of the minimum state of charge value of the single cell and the rated capacity can represent the actual remaining capacity of the single cell. The difference between the total power absorbed and the total power released can determine the total capacity actually absorbed by the single cell.

[0119] In this embodiment, since the minimum state of charge value of the battery pack can monitor the discharge capacity of the single cell, the actual remaining capacity of the single cell can be determined based on the product of the minimum state of charge value of the battery pack and the rated capacity. The total amount of electricity actually absorbed by the single cell can be determined based on the difference between the total amount of electricity absorbed and the total amount of electricity released, and the actual capacity of the single cell can be determined based on the actual remaining capacity and the total amount of electricity actually absorbed by the single cell.

[0120] It should be understood that since the battery pack will undergo open circuit voltage correction, the state of charge value of the battery pack will be calibrated once each time the open circuit voltage correction is performed. However, if the battery pack is constantly undergoing open circuit voltage correction, it is impossible to determine the state of charge value of the battery pack. Therefore, after the battery pack undergoes open circuit voltage correction, it is necessary to determine whether the preset conditions for determining the actual capacity of the battery pack are met.

[0121] The following describes the content of judging whether the preset condition for determining the actual capacity of the battery pack is satisfied.

[0122] In a possible implementation, after the open circuit voltage of the battery pack is corrected, the mileage and charging information of the vehicle are obtained, and based on the mileage and charging information, it is determined whether a preset condition for determining the actual capacity of the battery pack is met.

[0123] Among them, the vehicle's mileage is used to monitor the vehicle's driving distance, and the vehicle's charging information is used to monitor the charging time interval of the vehicle's battery.

[0124] In this embodiment, after the battery pack has undergone open circuit voltage correction, the vehicle's mileage and charging information are obtained, and based on the mileage and charging information, it is determined whether the preset conditions for determining the actual capacity of the battery pack are met, so as to determine whether to determine the actual capacity of the battery pack based on the mileage and charging information.

[0125] In order to explain the above implementation more clearly, the above implementation is explained in several parts below.

[0126] The first part describes the contents of obtaining the vehicle's mileage and charging information after the battery pack has been corrected for open circuit voltage.

[0127] In a possible implementation, after the open circuit voltage of the battery pack is corrected, the current mileage of the vehicle is taken as a starting point and the mileage of the vehicle is obtained based on the global positioning system (GPS) of the vehicle.

[0128] It should be understood that in order to avoid multiple open circuit voltage corrections affecting the state of charge value of the battery pack, after the battery pack undergoes open circuit voltage correction, the vehicle's mileage is obtained starting from the current mileage of the vehicle.

[0129] In some embodiments, after the open circuit voltage of the battery pack is corrected, the current mileage of the vehicle is obtained based on the GPS of the vehicle; and the mileage of the vehicle is obtained with the current mileage as the starting point.

[0130] For example, the current mileage is 20 kilometers (KM), the total mileage of the vehicle obtained from the current mileage is 120KM, and the mileage of the vehicle obtained based on the vehicle's GPS is 100KM.

[0131] In this embodiment, after the battery pack is corrected for open circuit voltage, the vehicle's mileage is obtained based on the vehicle's GPS, starting from the vehicle's current mileage, so as to determine whether to perform the step of determining the actual capacity of the battery pack based on the mileage.

[0132] In a possible implementation, the charging information of the vehicle is acquired based on a timer.

[0133] The charging information includes the charging time interval of the vehicle.

[0134] It should be understood that the charging time interval of the vehicle is used to represent the time interval from when the battery pack is fully charged after the open circuit voltage is corrected.

[0135] In some embodiments, after the open circuit voltage of the battery pack is corrected, the current time of the vehicle is obtained based on a timer; and the charging time interval of the vehicle is obtained with the current time as the starting point.

[0136] For example, the current time is 0, and the charging time interval of the vehicle obtained from the current time is 48 hours.

[0137] In this embodiment, the charging information of the vehicle is obtained based on the timer, so as to determine whether to perform the step of determining the actual capacity of the battery pack based on the charging information.

[0138] The second part describes the content of judging whether the preset conditions for determining the actual capacity of the battery pack are met based on the mileage and charging information.

[0139] In one possible implementation, the preset condition is met when the mileage is less than or equal to a first preset value, the charging time interval of the vehicle is less than or equal to a second preset value, and the battery pack has not undergone additional correction; when the preset condition is met, the actual capacity of the battery pack is determined.

[0140] The first preset value is automatically determined by the vehicle control unit, or is set by a technician according to actual conditions, and the present application embodiment does not limit this. For example, the first preset value may be 100 kilometers.

[0141] The additional correction means that the state of charge value of the battery pack is corrected again in addition to the open circuit voltage correction. The battery pack does not undergo additional correction means that in addition to the open circuit voltage correction, the state of charge value of the battery pack is not corrected in any way.

[0142] The process of determining the actual capacity of the battery pack indicates determining the actual capacity based on the rated capacity, the minimum state of charge value, and the charge difference value.

[0143] The second preset value is automatically determined by the vehicle control unit, or is set by a technician according to actual conditions, and the present application embodiment does not limit this. For example, the second preset value may be 2 days.

[0144] It should be understood that the mileage less than or equal to the first preset value indicates that the current mileage of the vehicle is short, so the battery pack discharge process is short, and the state of charge value of the battery pack changes less, so the state of charge value of the battery pack does not need to be re-calibrated for open circuit voltage. The charging time interval of the vehicle is less than or equal to the second preset value, which indicates that the charging time interval of the battery pack is short, and the state of charge value of the battery pack changes less, so the state of charge value of the battery pack does not need to be re-calibrated for open circuit voltage. The battery pack has not undergone additional correction, which indicates that the state of charge value of the battery pack has not been corrected again, so the current state of charge value is more accurate. In this case, it is judged that the conditions for determining the actual capacity of the battery pack are met.

[0145] For example, after the open circuit voltage of the battery pack is corrected, it is determined that the vehicle's mileage is 30 km, the battery pack's charging interval is 3 hours, and the battery pack has not been corrected again, thereby judging that the conditions for determining the actual capacity of the battery pack are met.

[0146] In this embodiment, when the mileage is less than or equal to the first preset value, the charging time interval of the vehicle is less than or equal to the second preset value, and the battery pack has not undergone additional correction, it is determined that the state of charge value of the battery pack has changed slightly, and no open circuit voltage correction is required. In this case, it is determined that the preset conditions are met; when the preset conditions are met, the actual capacity of the battery pack is determined. That is, when the state of charge value of the battery pack changes slightly, the actual capacity of the battery pack can be accurately determined based on the current accurate state of charge value.

[0147] In one possible implementation, when the mileage is greater than a first preset value, and / or the vehicle's charging time interval is greater than a second preset value, and / or the battery pack undergoes additional correction, the preset condition is not met; when the preset condition is not met, the process of determining the actual capacity of the battery pack is terminated.

[0148] Terminating the process of determining the actual capacity of the battery pack means terminating the acquisition of the rated capacity of the battery pack on the vehicle and the state of charge value of each single cell in the battery pack.

[0149] It should be understood that if the mileage is greater than the first preset value, it means that the current mileage of the vehicle is long, so the discharge process of the battery pack is long, and the state of charge value of the battery pack changes greatly, so the state of charge value of the battery pack needs to be re-calibrated for open circuit voltage. If the charging time interval of the vehicle is greater than the second preset value, it means that the charging time interval of the battery pack is long, and the state of charge value of the battery pack changes greatly, so the state of charge value of the battery pack also needs to be re-calibrated for open circuit voltage. The battery pack undergoing additional correction means that the state of charge value of the battery pack has been corrected again, so the current state of charge value is more, and the minimum state of charge value of the single cell cannot be determined based on the current state of charge value. In this case, it is judged that the conditions for determining the actual capacity of the battery pack are not met.

[0150] For example, after the open circuit voltage of the battery pack is corrected, it is determined that the vehicle's mileage is 230 km, the battery pack's charging interval is 5 days, or the battery pack is corrected again for open circuit voltage, thereby determining that the actual capacity of the battery pack is not met.

[0151] In some embodiments, when the preset condition is not met, the state of charge value of the battery pack changes greatly or the current state of charge value is large. In this case, if the actual capacity of the battery is determined based on the current state of charge value, the actual capacity of the battery will be inaccurate. To avoid inaccurate determination of the actual capacity of the battery, the rated capacity of the battery pack on the vehicle and the state of charge of each single cell in the battery pack are terminated.

[0152] For example, when the charging time interval of the battery pack is 5 days, the acquisition of the rated capacity of the battery pack and the state of charge value of each single battery in the battery pack is terminated.

[0153] In this embodiment, when the mileage is greater than the first preset value, and / or the charging time interval of the vehicle is greater than the second preset value, it is determined that the state of charge value of the battery pack has changed slightly, and the open circuit voltage correction needs to be performed again. However, if the battery pack undergoes additional correction again after the open circuit voltage correction, the minimum state of charge value of the single cell cannot be determined based on the current state of charge value. In this case, the state of charge value of the battery pack changes greatly and does not meet the preset conditions; when the preset conditions are not met, the actual capacity of the battery pack is terminated to reduce the impact of the inaccurate state of charge value of the battery pack on the determination of the actual capacity.

[0154] The embodiment of the present application provides a method for determining the actual capacity of a battery, obtaining the rated capacity of a battery pack on a vehicle and the state of charge value of each single cell in the battery pack, and determining the minimum state of charge value, wherein the battery pack includes one or more single cells. The minimum state of charge value obtained has an error. In order to reduce the error of the state of charge value, after the battery pack is corrected for open circuit voltage, the total amount of electricity absorbed and the total amount of electricity released by the battery pack during the charging process until it is fully charged are determined with the current electricity as the starting point. The electricity difference is determined based on the total amount of electricity absorbed and the total amount of electricity released, and the actual capacity of the battery can be determined based on the rated capacity, the minimum state of charge value and the electricity difference. Since the rated capacity of the battery pack is used to indicate the maximum electrical energy storage capacity of the battery and the minimum state of charge value of the single cell can monitor the minimum remaining capacity of the battery pack, the actual capacity of the battery pack can be re-determined based on the minimum state of charge value, the rated capacity and the electricity difference, thereby improving the accuracy of determining the actual capacity of the battery.

[0155] Figure 3 It is a schematic flow chart of a method for evaluating the health status of a battery pack improved by an embodiment of the present application.

[0156] For example, Figure 3 As shown, the execution subject of the method is a vehicle control unit, and the method 300 includes:

[0157] Step 301 : after the open circuit voltage of the battery pack is corrected, it is determined whether a preset condition for determining the actual capacity of the battery pack is met.

[0158] It is understandable that the detailed steps of determining whether the preset condition for determining the actual capacity of the battery pack is satisfied can be referred to the aforementioned step 204, which will not be described in detail here.

[0159] Step 302: When a preset condition is met, determine the actual capacity of the battery pack.

[0160] It is understandable that the detailed steps of determining the actual capacity of the battery pack can refer to the aforementioned step 204, which will not be described in detail here.

[0161] Step 303: when the preset condition is not met, the determination of the actual capacity of the battery pack is terminated.

[0162] It is understandable that the detailed steps of terminating the determination of the actual capacity of the battery pack can be referred to the aforementioned step 204, which will not be described in detail here.

[0163] Step 304: Determine whether the health status of the battery pack is healthy based on the actual capacity and the rated capacity.

[0164] It should be understood that since the actual capacity of the battery is used to indicate the current maximum electrical energy storage capability of the battery and the rated capacity is the theoretical maximum capacity of the battery pack, the health status of the battery pack can be evaluated by comparing the actual capacity with the rated capacity.

[0165] In one possible implementation, a ratio of the actual capacity to the rated capacity is determined; when the ratio is greater than or equal to a fifth preset value, the health status of the battery pack is determined to be healthy; when the ratio is less than the fifth preset value, the health status of the battery pack is determined to be unhealthy.

[0166] The fifth preset value is automatically determined by the vehicle control unit, or is set by a technician according to actual conditions, and the present application embodiment does not limit this. For example, the fifth preset value may be 80%.

[0167] It should be understood that the health status of the battery pack can be determined based on the ratio of the actual capacity to the rated capacity of the battery, that is, based on the health status, it is possible to ensure that the battery pack operates in an optimal state, thereby extending the service life of the battery.

[0168] In some embodiments, the formula for determining the health of a battery pack is as follows.

[0169] The health status of the battery pack = actual capacity / rated capacity*100%.

[0170] In this case, the ratio of the actual capacity to the rated capacity is determined; when the ratio is greater than or equal to the fifth preset value, the health status of the battery pack is determined to be healthy; when the ratio is less than the fifth preset value, the health status of the battery pack is determined to be unhealthy, thereby accurately evaluating the health status of the battery pack based on the ratio of the actual capacity to the rated capacity of the battery pack, so as to trigger an alarm prompt for the health status of the battery pack according to the health status of the battery pack.

[0171] Step 305: When the ratio is greater than or equal to a fifth preset value, it is determined that the health status of the battery pack is healthy.

[0172] It should be understood that a healthy state of the battery pack indicates that the battery pack can be used normally, that is, the battery pack can provide electrical energy for the power system of the vehicle.

[0173] In some embodiments, when it is determined that the health status of the battery pack is healthy, it is determined whether the health status of the battery pack is greater than a sixth preset value. When the health status of the battery pack is greater than or equal to the fifth preset value and less than the sixth preset value, an alarm message for the health status of the battery pack is triggered. When the health status of the battery pack is greater than or equal to the sixth preset value, an alarm message for the health status of the battery pack is not triggered.

[0174] The sixth preset value is automatically determined by the vehicle control unit, or is set by a technician according to actual conditions, and the present application embodiment does not limit this. For example, the sixth preset value may be 90%.

[0175] The alarm information regarding the health status of the battery pack includes an alarm prompt text and an alarm prompt audio regarding the health status of the battery pack.

[0176] It should be understood that if the health status of the battery pack is greater than or equal to the fifth preset value and less than the sixth preset value, it means that the health status of the battery pack is healthy, so the battery pack can be used normally, and the user can be reminded only through the alarm prompt text.

[0177] In some embodiments, the warning prompt text is displayed on the dashboard or on-board screen of the vehicle.

[0178] In this implementation, when it is determined that the health status of the battery pack is healthy, it is determined whether the health status of the battery pack is greater than a sixth preset value. When the health status of the battery pack is greater than or equal to the fifth preset value and less than the sixth preset value, an alarm message for the health status of the battery pack is triggered. When the health status of the battery pack is greater than or equal to the sixth preset value, an alarm message for the health status of the battery pack is not triggered. That is, different alarm prompts are triggered for different health statuses of the battery pack to prompt the user, thereby improving the driving safety of the vehicle.

[0179] Step 306: When the ratio is less than a fifth preset value, it is determined that the health status of the battery pack is unhealthy.

[0180] It should be understood that if the health status of the battery pack is unhealthy, it means that the battery pack cannot be used normally, that is, the battery pack cannot provide electrical energy for the power system of the vehicle.

[0181] In some embodiments, when the health status of the battery pack is determined to be unhealthy, an alarm message regarding the health status of the battery pack is triggered.

[0182] The alarm information regarding the health status of the battery pack includes an alarm prompt text and an alarm prompt audio regarding the health status of the battery pack.

[0183] It should be understood that if the health condition of the battery pack is unhealthy, the battery pack cannot be used normally. In order to avoid spontaneous combustion of the battery pack due to the use of a damaged battery pack, the user is reminded through an alarm prompt text and an alarm prompt audio.

[0184] In some embodiments, the warning prompt text is displayed on the dashboard or on-board screen of the vehicle.

[0185] In some embodiments, the warning audio is broadcast on the vehicle's onboard audio system.

[0186] For example, the alarm prompt text or the alarm prompt audio may be "The battery is damaged, please go to a repair shop for repair as soon as possible."

[0187] In this embodiment, when the health status of the battery pack is determined to be unhealthy, an alarm message for the health status of the battery pack is triggered. That is, different alarm prompts are triggered for different health status of the battery pack to prompt the user, thereby improving the driving safety of the vehicle.

[0188] Figure 4 It is a structural schematic diagram of a device for determining the actual capacity of a battery provided in an embodiment of the present application.

[0189] For example, Figure 4 As shown, the device 400 includes:

[0190] The acquisition module 401 is used to acquire the rated capacity of the battery pack on the vehicle and the state of charge value of each single battery in the battery pack, and determine the minimum state of charge value, the battery pack includes one or more single batteries;

[0191] A total power release determination module 402 is used to determine the total power absorbed by the battery pack during the charging process until it is fully charged and the total power released during the discharging process until it is fully charged, taking the current power as the starting point after the battery pack is corrected for the open circuit voltage;

[0192] The power difference determination module 403 is used to determine the power difference according to the total power absorbed and the total power released;

[0193] The module 402 for determining the total amount of electricity released is used to determine the actual capacity of the battery pack based on the rated capacity, the minimum state of charge value and the electricity difference value.

[0194] In a possible implementation manner, the device 400 further includes:

[0195] A power difference determination module 403 is used to determine the actual rated capacity of the battery pack according to the product of the rated capacity and the minimum state of charge value;

[0196] The module 402 for determining the total amount of electricity released is used to determine the actual capacity according to the actual rated capacity and the difference in electricity amount.

[0197] In a possible implementation manner, the device 400 further includes:

[0198] The acquisition module 401 is used to acquire the mileage and charging information of the vehicle after the open circuit voltage of the battery pack is corrected;

[0199] The total power release determination module 402 is used to determine whether a preset condition for determining the actual capacity of the battery pack is met according to the driving mileage and charging information;

[0200] A module 402 for determining the total amount of power released is used to determine the actual capacity of the battery pack when a preset condition is met;

[0201] The module 402 for determining the total amount of electricity to be released is configured to stop determining the actual capacity of the battery pack when a preset condition is not met.

[0202] In a possible implementation manner, the device 400 further includes:

[0203] A module 402 for determining the total amount of electricity released is used to satisfy a preset condition when the driving mileage is less than or equal to a first preset value, the charging time interval of the vehicle is less than or equal to a second preset value, and the battery pack has not undergone additional correction;

[0204] The module 402 for determining the total amount of electricity released is configured to determine that a preset condition is not satisfied when the driving mileage is greater than a first preset value, and / or the charging time interval of the vehicle is greater than a second preset value, and / or the battery pack undergoes additional correction.

[0205] In a possible implementation manner, the device 400 further includes:

[0206] The correction module is used to correct the open circuit voltage of the battery pack.

[0207] In a possible implementation manner, the device 400 further includes:

[0208] a measuring module, configured to measure an open circuit voltage of the battery pack when a temperature of the battery pack is less than or equal to a third preset value and a current of the battery pack is less than or equal to a fourth preset value;

[0209] A search module, used to search for a reference state of charge value of each single battery in the battery pack corresponding to the open circuit voltage in a corresponding relationship table between the open circuit voltage and the state of charge value;

[0210] The correction module is used to correct the state of charge value of each single cell in the battery pack to the reference state of charge value of each single cell when the reference state of charge value of each single cell does not match the state of charge value of each single cell in the battery pack.

[0211] In a possible implementation manner, the device 400 further includes:

[0212] Evaluation module to assess the health of the battery pack based on actual capacity and rated capacity.

[0213] In a possible implementation manner, the device 400 further includes:

[0214] The power difference determination module 403 is used to determine the ratio of the actual capacity to the rated capacity;

[0215] A module 402 for determining the total amount of electricity released is used to determine that the health status of the battery pack is healthy when the ratio is greater than or equal to a fifth preset value;

[0216] The module 402 for determining the total amount of power released is configured to determine that the health status of the battery pack is unhealthy when the ratio is less than a fifth preset value.

[0217] Figure 5 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application.

[0218] For example, Figure 5 As shown, the vehicle 500 includes: a memory 501 and a processor 502, wherein the memory 501 stores an executable program code 503, and the processor 502 is used to call and execute the executable program code 503 to perform a method for determining the actual capacity of a battery.

[0219] In addition, an embodiment of the present application also protects a device, which may include a memory and a processor, wherein the memory stores an executable program code, and the processor is used to call and execute the executable program code to perform a method for determining the actual capacity of a battery provided in an embodiment of the present application.

[0220] In this embodiment, the functional modules of the device can be divided according to the above method example. For example, each functional module can be corresponded, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0221] In the case of dividing each functional module according to each function, the device may also include an evaluation module, a search module, a correction module, etc. It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0222] It should be understood that the device provided in this embodiment is used to execute the above-mentioned method for determining the actual capacity of a battery, and thus can achieve the same effect as the above-mentioned implementation method.

[0223] In the case of an integrated unit, the device may include a processing module and a storage module. When the device is applied to a vehicle, the processing module may be used to control and manage the actions of the vehicle. The storage module may be used to support the vehicle in executing related program codes, etc.

[0224] The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits shown in conjunction with the disclosure of the present application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory.

[0225] In addition, the device provided in the embodiments of the present application may specifically be a chip, a component or a module, and the chip may include a connected processor and a memory; wherein the memory is used to store instructions, and when the processor calls and executes the instructions, the chip can execute a method for determining the actual capacity of a battery provided in the above embodiment.

[0226] This embodiment also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is executed on a computer, the computer executes the above-mentioned related method steps to implement a method for determining the actual capacity of a battery provided in the above embodiment.

[0227] This embodiment also provides a computer program product. When the computer program product is run on a computer, the computer is caused to execute the above-mentioned related steps to implement a method for determining the actual capacity of a battery provided in the above embodiment.

[0228] Among them, the device, computer-readable storage medium, computer program product or chip provided in this embodiment is used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here.

[0229] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0230] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0231] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for determining the actual capacity of a battery, characterized in that: The method comprises: Obtaining a rated capacity of a battery pack on a vehicle and a state of charge value of each single battery in the battery pack, and determining a minimum state of charge value, wherein the battery pack includes one or more single batteries; After the open circuit voltage of the battery pack is corrected, the total power absorbed and the total power released by the battery pack during the charging process until the battery pack is fully charged are determined with the current power as the starting point, wherein the total power released includes the power released by the battery pack during self-discharge and the power released by the battery pack during use; Determine the power difference according to the absorbed total power and the released total power; An actual capacity of the battery pack is determined based on the rated capacity, the minimum state of charge value, and the charge difference value.

2. The method according to claim 1, characterized in that The determining the actual capacity of the battery pack based on the rated capacity, the minimum state of charge value and the power difference value includes: determining an actual rated capacity of the battery pack according to a product of the rated capacity and the minimum state of charge value; The actual capacity is determined according to the actual rated capacity and the power difference.

3. The method according to claim 1 or 2, characterized in that: Before determining the actual capacity of the battery pack, the method further includes: After the open circuit voltage of the battery pack is corrected, obtaining the mileage and charging information of the vehicle; Determining whether a preset condition for determining an actual capacity of the battery pack is met according to the driving mileage and the charging information; When the preset condition is met, the actual capacity of the battery pack is determined.

4. The method according to claim 3, characterized in that: The charging information includes a charging time interval of the vehicle, and judging whether a preset condition for determining an actual capacity of the battery pack is met based on the driving mileage and the charging information includes: The preset condition is satisfied when the driving mileage is less than or equal to a first preset value, the charging time interval of the vehicle is less than or equal to a second preset value, and the battery pack has not undergone additional correction; When the driving mileage is greater than a first preset value, and / or the charging time interval of the vehicle is greater than a second preset value, and / or the battery pack undergoes additional correction, the preset condition is not satisfied.

5. The method according to claim 1, characterized in that The method further comprises: The open circuit voltage of the battery pack is corrected.

6. The method according to claim 5, characterized in that The open circuit voltage correction of the battery pack includes: When the temperature of the battery pack is less than or equal to a third preset value and the current of the battery pack is less than or equal to a fourth preset value, measuring the open circuit voltage of the battery pack; In a correspondence table between open circuit voltage and state of charge value, searching for a reference state of charge value of each single battery in the battery pack corresponding to the open circuit voltage; When the reference state of charge value of each single cell does not match the state of charge value of each single cell in the battery pack, the state of charge value of each single cell in the battery pack is corrected to the reference state of charge value of each single cell.

7. The method according to any one of claims 1 to 4, characterized in that The method further comprises: The health status of the battery pack is evaluated according to the actual capacity and the rated capacity.

8. The method according to claim 7, characterized in that The evaluating the health status of the battery pack according to the actual capacity and the rated capacity includes: determining a ratio of the actual capacity to the rated capacity; When the ratio is greater than or equal to a fifth preset value, determining that the health status of the battery pack is healthy; When the ratio is less than a fifth preset value, it is determined that the health status of the battery pack is unhealthy.

9. A vehicle, characterized in that: The vehicle comprises: A memory for storing executable program codes; A processor, configured to call and run the executable program code from the memory, so that the vehicle executes the method according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed, the method according to any one of claims 1 to 8 is implemented.

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