Battery state of health determination method, apparatus, battery management system, and storage medium

Abstract

The application discloses a battery health state determination method and device, a battery management system and a storage medium, and belongs to the technical field of vehicles. The method is to first determine the current inherent capacity of each battery unit based on the current residual capacity of each battery unit in the battery system and the current discharge capacity of the battery system, and then determine the current health state of the battery system based on the current inherent capacity and the nominal capacity of each battery unit. Therefore, when determining the health state of the battery system, the method uses current data, so the problem of gradually accumulating errors over time does not occur, thereby improving the accuracy of the battery system health state determination.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a method, apparatus, battery management system, and storage medium for determining battery health status. Background Technology

[0002] For electric vehicles, after the battery system has been working for a period of time, its capacity will decrease due to aging. The indicator for judging the aging of the battery system is its health status.

[0003] In related technologies, the main approach is to record the cumulative capacity flowing into and out of the battery system through the battery management system, convert this capacity into the number of charge-discharge cycles, and then look up the current capacity of the battery system based on the relationship table between the number of charge-discharge cycles and the capacity obtained from laboratory measurements. The health status of the battery system is then determined based on the current capacity of the battery system.

[0004] However, capacity errors are inevitable in the calculation of cumulative capacity, and these errors accumulate over time, leading to a large error in the determination of the battery system's health status. Summary of the Invention

[0005] This application provides a method, apparatus, battery management system, and storage medium for determining battery health status, which can improve the accuracy of determining the health status of the battery system. The technical solution is as follows:

[0006] On the one hand, a method for determining battery health status is provided, the method comprising:

[0007] Obtain the remaining charge and nominal capacity of the battery system;

[0008] If the battery system meets the conditions based on the remaining power of the battery system, the current discharge capacity of the battery system and the voltage of each battery cell are obtained. The current discharge capacity of the battery system is the discharge capacity of the battery system up to the present after it is fully charged and enters the discharge state. The battery system includes multiple battery cells.

[0009] For each battery cell, the current remaining charge of the battery cell is determined based on the voltage of the battery cell;

[0010] Based on the current remaining charge of the battery cell and the current discharge capacity of the battery system, the current inherent capacity of the battery cell is determined, and the current inherent capacity of the battery cell is used to represent the capacity of the battery cell after it is fully charged.

[0011] Based on the inherent capacity of each battery cell and the nominal capacity, the current health status value of the battery system is determined, and the current health status value of the battery system is used to reflect the current health status of the battery system.

[0012] In one possible implementation, determining the current remaining charge of the battery cell based on its voltage includes:

[0013] Obtain the current temperature of the battery cell;

[0014] Determine the target temperature range to which the current temperature of the battery cell belongs;

[0015] First relationship data corresponding to the target temperature range is determined, and the first relationship data is used to represent the linear relationship between the voltage and remaining capacity of the battery cell within the target temperature range;

[0016] Based on the voltage of the battery cell and the first relationship data, the current remaining power of the battery cell is determined.

[0017] In another possible implementation, determining the first relational data corresponding to the target temperature range includes:

[0018] Obtain a parameter table of the battery cell in the target temperature range, the parameter table being obtained based on the open-circuit voltage and remaining charge of the battery cell;

[0019] Based on the parameter table, determine the open-circuit voltage corresponding to the remaining charge of the battery cell within a first preset range;

[0020] Based on the remaining charge of the battery cell within a first preset range and its corresponding open-circuit voltage, linear fitting is performed to obtain the first relationship data corresponding to the target temperature range.

[0021] In another possible implementation, determining the current inherent capacity of the battery cell based on its current remaining charge and the current discharge capacity of the battery system includes:

[0022] Determine the difference between 1 and the current remaining power of the battery cell to obtain the first difference;

[0023] The ratio of the current discharge capacity of the battery system to the first difference is determined to obtain the current inherent capacity of the battery cell.

[0024] In another possible implementation, determining the current state of health of the battery system based on the current inherent capacity of each battery cell and the nominal capacity includes:

[0025] The ratio of the current inherent capacity of each battery cell to the nominal capacity is determined to obtain the current health status value of each battery cell;

[0026] The minimum health state value is determined from the current health state values ​​of the plurality of battery cells, and the minimum health state value is determined as the current health state value of the battery system.

[0027] In another possible implementation, the method further includes:

[0028] If the remaining charge of the battery system is within a first preset range, and the battery system is first in a static state and then in a powered-on state, and the duration between the static state and the powered-on state is greater than a preset duration, then the battery system is determined to meet the conditions.

[0029] On the other hand, a battery health status determination device is provided, the device comprising:

[0030] The first acquisition module is used to acquire the remaining power and nominal capacity of the battery system;

[0031] The second acquisition module is used to acquire the current discharge capacity of the battery system and the voltage of each battery cell when the battery system meets the conditions based on the remaining power of the battery system. The current discharge capacity of the battery system is the discharge capacity of the battery system up to the present after it is fully charged and enters the discharge state. The battery system includes multiple battery cells.

[0032] The first determining module is used to determine the current remaining power of each battery cell based on the voltage of the battery cell.

[0033] The second determining module is used to determine the current inherent capacity of the battery cell based on the current remaining charge of the battery cell and the current discharge capacity of the battery system. The current inherent capacity of the battery cell is used to represent the capacity of the battery cell after it is fully charged.

[0034] The third determining module is used to determine the current health status value of the battery system based on the current inherent capacity of each battery cell and the nominal capacity. The current health status value of the battery system is used to reflect the current health status of the battery system.

[0035] In one possible implementation, the first determining module is configured to: acquire the current temperature of the battery cell; determine the target temperature range to which the current temperature of the battery cell belongs; determine first relationship data corresponding to the target temperature range, wherein the first relationship data is used to represent the linear relationship between the voltage and remaining charge of the battery cell within the target temperature range; and determine the current remaining charge of the battery cell based on the voltage of the battery cell and the first relationship data.

[0036] In another possible implementation, the device further includes:

[0037] The third acquisition module is used to acquire a parameter table of the battery cell in the target temperature range, the parameter table being obtained based on the open-circuit voltage and remaining charge of the battery cell;

[0038] The fourth determining module is used to determine the open-circuit voltage corresponding to the remaining charge of the battery cell within a first preset range based on the parameter table.

[0039] The fitting module is used to perform linear fitting based on the remaining charge of the battery cell within a first preset range and its corresponding open-circuit voltage to obtain the first relationship data corresponding to the target temperature range.

[0040] In another possible implementation, the second determining module is used to determine the difference between 1 and the current remaining charge of the battery cell to obtain a first difference; and to determine the ratio of the current discharge capacity of the battery system to the first difference to obtain the current inherent capacity of the battery cell.

[0041] In another possible implementation, the third determining module is used to determine the ratio of the current inherent capacity of each battery cell to the nominal capacity to obtain the current health status value of each battery cell; determine the minimum health status value from the current health status values ​​of the plurality of battery cells, and determine the minimum health status value as the current health status value of the battery system.

[0042] In another possible implementation, the device further includes:

[0043] The fifth determining module is used to determine that the battery system meets the conditions when the remaining power of the battery system is within a first preset range, and the battery system is first in a static state and then in a powered-on state, and the duration between the static state and the powered-on state is greater than a preset duration.

[0044] On the other hand, a battery management system is provided, the battery management system including a processor and a memory, the memory storing at least one piece of program code, the at least one piece of program code being loaded and executed by the processor to implement the battery health status determination method described in any of the above.

[0045] On the other hand, a computer-readable storage medium is provided, wherein at least one piece of program code is stored in the computer-readable storage medium, the at least one piece of program code being loaded and executed by a processor to implement the battery health status determination method described in any of the preceding claims.

[0046] On the other hand, a computer program product is provided, wherein at least one piece of program code is stored in the computer program product, the at least one piece of program code being loaded and executed by a processor to implement the battery health status determination method described in any of the above claims.

[0047] This application provides a method for determining the health status of a battery. The method first determines the current inherent capacity of each battery cell based on its remaining charge and the current discharge capacity of the battery system. Then, based on the inherent capacity and nominal capacity of each battery cell, it determines the current health status of the battery system. Therefore, this method uses current data to determine the health status of the battery system, thus avoiding the problem of errors accumulating over time and improving the accuracy of determining the battery system's health status.

[0048] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this disclosure. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the implementation environment of a battery health status determination method provided in an embodiment of this application;

[0050] Figure 2 This is a flowchart of a method for determining battery health status provided in an embodiment of this application;

[0051] Figure 3 This is a schematic diagram of a battery health status determination device provided in an embodiment of this application;

[0052] Figure 4 This is a structural block diagram of a battery management system provided in an embodiment of this application. Detailed Implementation

[0053] To make the technical solution and advantages of this application clearer, the embodiments of this application will be described in further detail below.

[0054] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0055] It should be noted that all information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, stored data, displayed data, etc.), and signals involved in this application are authorized by the user or fully authorized by all parties, and the collection, use, and processing of related data must comply with the relevant laws, regulations, and standards of the relevant countries and regions. For example, the remaining battery power and discharge capacity involved in this application were obtained with full authorization.

[0056] Figure 1 This is a schematic diagram illustrating the implementation environment of a battery health status determination method provided in this application embodiment. See also... Figure 1 The implementation environment includes a battery management system (BMS) 101 and a battery system 102. The battery management system 101 can monitor the health status of the battery system 102 and manage and maintain each battery cell 1021.

[0057] The battery system 102 includes multiple battery cells 1021, which can be connected in series. Each battery cell 1021 may include one or more individual battery cells. If the battery cell 1021 includes multiple individual battery cells, these individual battery cells can be connected in parallel. The individual battery cells can be lithium batteries or other types of batteries, without specific limitations.

[0058] Due to differences in spatial distribution and inherent characteristics, the aging rates of multiple battery cells 1021 vary, resulting in different health states. The battery cell 1021 with the worst health state determines the health state of the battery system 102; therefore, the health state of the battery system 102 should be characterized by the battery cell 1021 with the worst health state.

[0059] Based on this, the battery management system 101 first determines the health status value of each battery cell 1021, and then determines the minimum health status value as the current health status value of the battery system 102. The health status value reflects the health status of the battery system 102. The higher the health status value of the battery system 102, the healthier the battery system 102 is.

[0060] Figure 2 This is a flowchart of a battery health status determination method provided in an embodiment of this application, executed by the battery management system. See also... Figure 2 The method includes:

[0061] Step 201: The battery management system obtains the remaining charge and nominal capacity of the battery system.

[0062] The battery management system obtains the nominal capacity of the battery system, which refers to the discharge capacity of the battery at 0.2C discharge.

[0063] The battery management system also determines the remaining power of the battery system in real time or periodically, and determines whether the remaining power of the battery system is within a first preset range. If the remaining power of the battery system is within the first preset range, it determines whether the battery system is currently in a static state and whether the duration of the static state exceeds a preset duration. If the battery system is first in a static state and then in a powered-on state, and the duration between the static state and the powered-on state is greater than the preset duration, the battery management system determines that the battery system meets the conditions and then executes step 202.

[0064] The "resting state" refers to a state where the battery system is neither charging nor discharging, while the "powered state" refers to a state where the battery system is either charging or discharging. The preset duration can be set and changed as needed; for example, a preset duration of 2 hours. The first preset range can also be set and changed as needed; for example, a first preset range of 25% to 45%.

[0065] Step 202: If the battery system meets the conditions based on the remaining charge of the battery system, the battery management system obtains the current discharge capacity of the battery system and the voltage of each battery cell.

[0066] The current discharge capacity of the battery system is the discharge capacity up to the present after the battery system has been fully charged and entered the discharge state. The battery system consists of multiple battery cells.

[0067] In this embodiment, the battery management system can pre-set a full-charge status flag in the data storage unit. When the battery system enters charging mode, whether AC or DC, and is fully charged, the battery management system sets the full-charge status flag. When the full-charge status flag is set and the battery system enters discharging mode, the battery management system acquires the current value of the battery system in real time. If the battery management system determines that the battery system meets the conditions, it determines the discharge time from the start of discharge to the current time, and integrates the current value and discharge time to obtain the current discharge capacity of the battery system.

[0068] In this step, the battery management system also obtains the voltage of each battery cell through a voltage sensor.

[0069] Step 203: For each battery cell, the battery management system determines the current remaining charge of the battery cell based on its voltage.

[0070] In this step, for each battery cell, the battery management system obtains the current temperature of the battery cell and determines the target temperature range to which the current temperature of the battery cell belongs; determines the first relationship data corresponding to the target temperature range, which is used to represent the linear relationship between the voltage and remaining capacity of the battery cell within the target temperature range; and determines the current remaining capacity of the battery cell based on the voltage of the battery cell and the first relationship data.

[0071] In this implementation, the battery management system can determine the target temperature range to which the current temperature of the battery cell belongs based on the current temperature of the battery cell. Different temperature ranges correspond to different first relation data. The battery management system determines the first relation data corresponding to the target temperature range, and then determines the remaining power corresponding to the voltage of the battery cell based on the first relation data, thereby obtaining the current remaining power of the battery cell.

[0072] Before step 203, the battery management system first divides multiple temperature ranges, for example, the multiple temperature ranges are [-20℃, -10℃], (-10℃, 0℃], (0℃, 10℃], (10℃, 20℃], (20℃, 30℃], and (30℃, 40℃], and then determines the first relationship data corresponding to each temperature range. When performing this step, the battery management system can directly determine the corresponding first relationship data based on the target temperature range.

[0073] The following explanation uses the determination of the first relationship data corresponding to the target temperature range as an example. The process is as follows: The battery management system obtains the parameter table of the battery cell in the target temperature range. Based on the parameter table, it determines the open circuit voltage corresponding to the remaining charge of the battery cell in the first preset range. Based on the remaining charge of the battery cell in the first preset range and its corresponding open circuit voltage, a linear fit is performed to obtain the first relationship data corresponding to the target temperature range.

[0074] This parameter table is based on the open circuit voltage (OCV) and remaining charge (SOC) of the battery cells. Different open circuit voltages correspond to different remaining charges. The battery management system determines the open circuit voltage corresponding to the remaining charge within a first preset range, and then performs linear fitting to obtain the first relationship data. The first relationship data is a linear function in one variable, with the open circuit voltage as the independent variable and the remaining charge as the dependent variable, or vice versa; no specific limitation is made in either case.

[0075] The first relationship data corresponding to other temperature ranges can also be obtained in the same way as described above, and will not be repeated here. It should be noted that, under the same temperature range conditions, multiple battery cells can correspond to the same first relationship data, or each battery cell can correspond to a separate first relationship data; this is not specifically limited. In this embodiment, only the example of multiple battery cells corresponding to the same first relationship data under the same temperature range is used for illustration. Furthermore, the finer the temperature range division, the more first relationship data there is, and the more accurate the final calculation result.

[0076] Step 204: The battery management system determines the current inherent capacity of the battery cell based on the current remaining charge of the battery cell and the current discharge capacity of the battery system.

[0077] The inherent capacity of a battery cell is used to represent the capacity of the battery cell when it is fully charged.

[0078] The current remaining capacity of a battery cell is calculated by subtracting the current discharge capacity after the full charge status flag is set from the current inherent capacity of the battery cell, and then dividing by the current inherent capacity of the battery cell. Based on this, the current inherent capacity of the battery cell can be calculated by reversing the current remaining capacity. The process is as follows: the battery management system determines the difference between 1 and the current remaining capacity of the battery cell to obtain the first difference; the ratio of the current discharge capacity of the battery system to the first difference is determined to obtain the current inherent capacity of the battery cell.

[0079] For example, SOC1 represents the current remaining charge of the battery cell, Cap1 represents the current discharge capacity of the battery system, and Cap x This represents the current inherent capacity of the battery cell.

[0080] Step 205: The battery management system determines the current state of health of the battery system based on the inherent capacity and nominal capacity of each battery cell.

[0081] The current State of Health (SOH) value of the battery system is used to reflect the current health status of the battery system.

[0082] In one possible implementation, the battery management system determines the ratio of the current inherent capacity to the nominal capacity of each battery cell to obtain the current state of health value of each battery cell; it then determines the minimum state of health value from the multiple current state of health values ​​of the battery cells and sets the minimum state of health value as the current state of health value of the battery system.

[0083] For example, Cap0 represents the nominal capacity of the battery system, and SOH x This represents the health status value of the battery system.

[0084] In another possible implementation, the battery management system determines the minimum intrinsic capacity from the current intrinsic capacities of multiple battery cells, determines the ratio of the minimum intrinsic capacity to the nominal capacity, and determines this ratio as the current state of health value of the battery system.

[0085] The method provided in this application first evaluates the inherent capacity or state of health value of each battery cell, and uses the minimum inherent capacity or state of health value to characterize the capacity of the battery system, thereby ensuring the accuracy of the available capacity of the battery system. Furthermore, the algorithm has a time complexity of O(n), does not involve floating-point operations or matrix operations, and is suitable for integration into a battery management system. The data used in each calculation is currently acquired, without secondary or cumulative calculations of parameters, keeping parameter errors within a very small range. Moreover, each calculation cycle is independent and does not interfere with each other, so errors do not accumulate or propagate over time.

[0086] In this embodiment, after the battery management system determines the health status value of the battery system, it can display the health status value of the battery system through the vehicle display screen, thereby making it easier for users to understand the health status of the battery system.

[0087] This application provides a method for determining the health status of a battery. The method first determines the current inherent capacity of each battery cell based on its remaining charge and the current discharge capacity of the battery system. Then, based on the inherent capacity and nominal capacity of each battery cell, it determines the current health status of the battery system. Therefore, this method uses current data to determine the health status of the battery system, thus avoiding the problem of errors accumulating over time and improving the accuracy of determining the battery system's health status.

[0088] Figure 3 This is a schematic diagram of a battery health status determination device provided in an embodiment of this application. See also... Figure 3 The device includes:

[0089] The first acquisition module 301 is used to acquire the remaining power and nominal capacity of the battery system;

[0090] The second acquisition module 302 is used to acquire the current discharge capacity of the battery system and the voltage of each battery cell when the battery system meets the conditions based on the remaining power of the battery system. The current discharge capacity of the battery system is the discharge capacity of the battery system up to the present after it is fully charged and enters the discharge state. The battery system includes multiple battery cells.

[0091] The first determining module 303 is used to determine the current remaining power of each battery cell based on the voltage of the battery cell.

[0092] The second determining module 304 is used to determine the current inherent capacity of the battery cell based on the current remaining charge of the battery cell and the current discharge capacity of the battery system. The current inherent capacity of the battery cell is used to represent the capacity of the battery cell after it is fully charged.

[0093] The third determining module 305 is used to determine the current health status value of the battery system based on the current inherent capacity and nominal capacity of each battery cell. The current health status value of the battery system is used to reflect the current health status of the battery system.

[0094] In one possible implementation, the first determining module 303 is used to obtain the current temperature of the battery cell; determine the target temperature range to which the current temperature of the battery cell belongs; determine the first relationship data corresponding to the target temperature range, the first relationship data being used to represent the linear relationship between the voltage and remaining capacity of the battery cell within the target temperature range; and determine the current remaining capacity of the battery cell based on the voltage of the battery cell and the first relationship data.

[0095] In another possible implementation, the device also includes:

[0096] The third acquisition module is used to acquire the parameter table of the battery cell in the target temperature range. The parameter table is obtained based on the open circuit voltage and remaining charge of the battery cell.

[0097] The fourth determining module is used to determine the open-circuit voltage corresponding to the remaining charge of the battery cell within a first preset range based on the parameter table.

[0098] The fitting module is used to perform linear fitting based on the remaining charge of the battery cell within a first preset range and its corresponding open-circuit voltage to obtain the first relationship data corresponding to the target temperature range.

[0099] In another possible implementation, the second determining module 304 is used to determine the difference between 1 and the current remaining charge of the battery cell to obtain a first difference; and to determine the ratio of the current discharge capacity of the battery system to the first difference to obtain the current inherent capacity of the battery cell.

[0100] In another possible implementation, the third determining module 305 is used to determine the ratio of the current inherent capacity to the nominal capacity of each battery cell to obtain the current health status value of each battery cell; and to determine the minimum health status value from the current health status values ​​of multiple battery cells, and to determine the minimum health status value as the current health status value of the battery system.

[0101] In another possible implementation, the device also includes:

[0102] The fifth determining module is used to determine that the battery system meets the conditions when the remaining power of the battery system is within a first preset range, and the battery system is first in a static state and then in a powered-on state, and the time between the static state and the powered-on state is greater than a preset time.

[0103] This application provides a battery health status determination device. This device first determines the current inherent capacity of each battery cell based on its current remaining charge and the current discharge capacity of the battery system. Then, based on the current inherent capacity and nominal capacity of each battery cell, it determines the current health status of the battery system. Therefore, this device uses current data to determine the battery system's health status, thus avoiding the problem of errors accumulating over time and improving the accuracy of battery system health status determination.

[0104] The block diagram of the battery management system can be found in [reference needed]. Figure 4The battery management system 400 can vary considerably depending on its configuration or performance. It may include a central processing unit (CPU) 401 and a memory 402. The memory 402 stores at least one line of program code, which is loaded and executed by the processor 401 to implement the aforementioned battery health status determination method. Of course, the battery management system 400 may also have wired or wireless network interfaces, a keyboard, and input / output interfaces for input / output. The battery management system 400 may also include other components for implementing device functions, which will not be elaborated upon here.

[0105] In an exemplary embodiment, a computer-readable storage medium is also provided, which stores at least one piece of program code that is loaded and executed by a processor to implement the battery health status determination method in the above embodiments.

[0106] In an exemplary embodiment, a computer program product is also provided, which stores at least one piece of program code, which is loaded and executed by a processor to implement the battery health status determination method in the above embodiments.

[0107] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0108] The above description is only for the purpose of enabling those skilled in the art to understand the technical solution of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for determining battery health status, characterized in that, The method includes: Obtain the remaining charge and nominal capacity of the battery system; If the battery system meets the conditions based on the remaining power of the battery system, the current discharge capacity of the battery system and the voltage of each battery cell are obtained. The current discharge capacity of the battery system is the discharge capacity of the battery system up to the present after it is fully charged and enters the discharge state. The battery system includes multiple battery cells. For each battery cell, the current remaining charge of the battery cell is determined based on the voltage of the battery cell; Based on the current remaining charge of the battery cell and the current discharge capacity of the battery system, the current inherent capacity of the battery cell is determined, and the current inherent capacity of the battery cell is used to represent the capacity of the battery cell after it is fully charged. The ratio of the current inherent capacity to the nominal capacity of each battery cell is determined to obtain the current health status value of each battery cell; The minimum health state value is determined from the current health state values ​​of multiple battery cells, and the minimum health state value is determined as the current health state value of the battery system. The current health state value of the battery system is used to reflect the current health state of the battery system. If the remaining charge of the battery system is within a first preset range, and the battery system is first in a static state and then in a powered-on state, and the duration between the static state and the powered-on state is greater than a preset duration, then the battery system is determined to meet the conditions.

2. The method according to claim 1, characterized in that, Determining the current remaining charge of the battery cell based on its voltage includes: Obtain the current temperature of the battery cell; Determine the target temperature range to which the current temperature of the battery cell belongs; First relationship data corresponding to the target temperature range is determined, and the first relationship data is used to represent the linear relationship between the voltage and remaining capacity of the battery cell within the target temperature range; Based on the voltage of the battery cell and the first relationship data, the current remaining power of the battery cell is determined.

3. The method according to claim 2, characterized in that, The determination of the first relationship data corresponding to the target temperature range includes: Obtain a parameter table of the battery cell in the target temperature range, the parameter table being obtained based on the open-circuit voltage and remaining charge of the battery cell; Based on the parameter table, determine the open-circuit voltage corresponding to the remaining charge of the battery cell within a first preset range; Based on the remaining charge of the battery cell within a first preset range and its corresponding open-circuit voltage, linear fitting is performed to obtain the first relationship data corresponding to the target temperature range.

4. The method according to claim 1, characterized in that, Determining the current inherent capacity of the battery cell based on its current remaining charge and the current discharge capacity of the battery system includes: Determine the difference between 1 and the current remaining power of the battery cell to obtain the first difference; The ratio of the current discharge capacity of the battery system to the first difference is determined to obtain the current inherent capacity of the battery cell.

5. A battery health status determination device, characterized in that, The device includes: The first acquisition module is used to acquire the remaining power and nominal capacity of the battery system; The second acquisition module is used to acquire the current discharge capacity of the battery system and the voltage of each battery cell when the battery system meets the conditions based on the remaining power of the battery system. The current discharge capacity of the battery system is the discharge capacity of the battery system up to the present after it is fully charged and enters the discharge state. The battery system includes multiple battery cells. The first determining module is used to determine the current remaining power of each battery cell based on the voltage of the battery cell. The second determining module is used to determine the current inherent capacity of the battery cell based on the current remaining charge of the battery cell and the current discharge capacity of the battery system. The current inherent capacity of the battery cell is used to represent the capacity of the battery cell after it is fully charged. The third determining module is used to determine the ratio of the current inherent capacity of each battery cell to the nominal capacity, thereby obtaining the current health status value of each battery cell; and to determine the minimum health status value from the multiple current health status values ​​of the battery cells, thereby determining the minimum health status value as the current health status value of the battery system, wherein the current health status value of the battery system is used to reflect the current health status of the battery system. The fifth determining module is used to determine that the battery system meets the conditions when the remaining power of the battery system is within a first preset range, and the battery system is first in a static state and then in a powered-on state, and the duration between the static state and the powered-on state is greater than a preset duration.

6. A battery management system, characterized in that, The battery management system includes a processor and a memory, wherein the memory stores at least one piece of program code, which is loaded and executed by the processor to implement the battery health status determination method as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one piece of program code, which is loaded and executed by a processor to implement the battery health status determination method as described in any one of claims 1 to 4.

8. A computer program product, characterized in that, The computer program product stores at least one piece of program code, which is loaded and executed by a processor to implement the battery health status determination method as described in any one of claims 1 to 4.

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