Battery system grouping test method and device and storage medium

Abstract

The invention discloses a battery system grouping test method and device and a storage medium. The method comprises the following steps: acquiring internal resistance data of a target number of battery cells in a battery system group; the battery cells with the internal resistance data within a preset range are selected to form a plurality of parallel test groups, each group comprises two kinds of cells with different internal resistances, and the internal resistance difference is determined by different groups; according to a preset charging strategy and a preset discharging strategy, carrying out charging and discharging circulation on the plurality of parallel test groups until it is observed that the life cycle of the battery cell is ended, and obtaining a plurality of groups of test data; and analyzing the multiple groups of test data, and determining the internal resistance range of the battery system group. Through the method and the device, the problem of poor battery system grouping test efficiency caused by long battery system grouping whole-pack cycle test time in related technologies is solved.

Description

Technical Field

[0001] The present application relates to the field of lithium batteries, and more specifically, to a battery system assembly testing method, device and storage medium. Background Art

[0002] Lithium batteries have become the preferred energy storage device in electric vehicles, energy storage systems and other fields due to their high energy density, long cycle life and environmental performance. In these applications, batteries often appear in the form of modules or battery packs, which are composed of multiple single cells in parallel or series. In order to optimize system performance and extend service life, the internal resistance difference between batteries needs to be considered when matching batteries. The difference in internal resistance will lead to uneven current distribution during battery charging and discharging, thereby accelerating the aging of certain battery cells and affecting the performance and life of the entire battery system. Therefore, testing the battery system matching is a key step to improve system performance, extend service life, control costs, ensure safety and optimize integration.

[0003] In the prior art, the system performance is often optimized by performing a full pack cycle test on the battery system. The full pack cycle test often needs to simulate the cycle life of the battery under actual use conditions, which usually means thousands or even tens of thousands of charge and discharge cycles. The test cycle may last for months to years, which seriously affects the speed of product development and market response time. Long-term testing not only consumes a lot of time, but also requires advanced testing equipment and a large amount of human resources, resulting in very high testing costs.

[0004] With regard to the problem in related technologies that the battery system assembly and whole pack cycle test takes a long time, resulting in poor battery system assembly test efficiency, no effective solution has been proposed so far. Summary of the invention

[0005] The main purpose of the present application is to provide a battery system grouping test method, device and storage medium to solve the problem in the related art that the battery system grouping whole pack cycle test time is long, resulting in poor battery system grouping test efficiency.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a test method for battery system grouping is provided. The method comprises: obtaining the internal resistance data of a target number of battery cells in the battery system grouping; selecting battery cells whose internal resistance data are within a preset range to form multiple parallel test groups, wherein each group contains two cells with different internal resistances, and the internal resistance difference is determined by different groupings; charging and discharging the multiple parallel test groups according to a preset charging strategy and a preset discharging strategy until the end of the life cycle of the battery cells is observed, and obtaining multiple groups of test data; analyzing the multiple groups of test data to determine the internal resistance extremes of the battery system grouping.

[0007] Furthermore, selecting battery cells whose internal resistance data are within a preset range to form multiple parallel test groups includes: determining the average value and standard deviation of the internal resistance data based on the internal resistance data of a target number of battery cells in the battery system grouping; and selecting battery cells whose internal resistance data are within a preset range based on the average value and the standard deviation to form multiple parallel test groups.

[0008] Furthermore, based on the mean value and the standard deviation, battery cells whose internal resistance data are within a preset range are selected to form multiple parallel test groups, including: calculating the minimum value of the internal resistance data based on the mean value and the standard deviation to obtain the minimum internal resistance; selecting target battery cells that differ from the minimum internal resistance by a positive integer multiple of the standard deviation, and determining the maximum internal resistance of each target battery cell, wherein the maximum internal resistance is within a preset range; and combining the battery cell with the minimum internal resistance in parallel with each target battery cell with the maximum internal resistance, and taking a preset number of parallel samples to construct multiple parallel test groups.

[0009] Furthermore, charging and discharging cycles are performed on multiple parallel test groups according to a preset charging strategy and a preset discharging strategy until the life cycle termination of the battery cell is observed, and multiple groups of test data are obtained, including: performing cycle tests on multiple parallel test groups according to a preset charging strategy and a preset discharging strategy until the life cycle termination conditions of the battery cell are reached; recording the test data of each parallel test group, wherein the test data includes at least: the number of cycles of the battery cell of each parallel test group, the maximum current and the minimum current during the charging and discharging process; and processing the test data of each parallel test group to obtain multiple groups of test data.

[0010] Furthermore, analyzing multiple groups of test data to determine the internal resistance range of the battery system grouping includes: traversing multiple groups of test data to obtain the number of cycles, maximum current and minimum current of the battery cells of each parallel test group; calculating the ratio between the maximum current and the minimum current in each parallel test group to obtain the current deviation coefficients of the multiple parallel test groups; determining the internal resistance range of the battery system grouping by comparing and analyzing the relationship between the internal resistance range of the multiple parallel test groups and the number of cycles of the battery cells of the multiple parallel test groups and the current deviation coefficients of the multiple parallel test groups.

[0011] Furthermore, after analyzing multiple groups of test data and determining the internal resistance range of the battery system, the method also includes: identifying a target parallel test group corresponding to the internal resistance range of the battery system from the multiple groups of test data; obtaining the corresponding maximum current and minimum current from the target parallel test group; calculating the ratio between the maximum current and the minimum current to obtain a target current deviation coefficient; and determining a charging strategy for the battery system based on the target current deviation coefficient.

[0012] In order to achieve the above-mentioned purpose, according to another aspect of the present application, a test device for battery system grouping is provided. The device comprises: a first acquisition unit, which acquires the internal resistance data of a target number of battery cells in the battery system grouping; a grouping unit, which selects battery cells with internal resistance data within a preset range to form multiple parallel test groups, wherein each group contains two cells with different internal resistances, and the internal resistance difference is determined by different groupings; a test unit, which performs charge and discharge cycles on the multiple parallel test groups according to a preset charging strategy and a preset discharging strategy until the end of the life cycle of the battery cells is observed, thereby obtaining multiple groups of test data; and an analysis unit, which analyzes the multiple groups of test data to determine the internal resistance extremes of the battery system grouping.

[0013] Furthermore, the assembly unit includes: a calculation module, which determines the average value and standard deviation of the internal resistance data based on the internal resistance data of a target number of battery cells in the battery system assembly; and an assembly module, which selects battery cells whose internal resistance data are within a preset range based on the average value and the standard deviation to form multiple parallel test groups.

[0014] Furthermore, the assembly module includes: a first calculation submodule, which calculates the minimum value of the internal resistance data according to the average value and the standard deviation to obtain the minimum internal resistance; a second calculation submodule, which selects target battery cells that differ from the minimum internal resistance by a positive integer multiple of the standard deviation, and determines the maximum internal resistance of each target battery cell, wherein the maximum internal resistance is within a preset range; and an assembly submodule, which assembles the battery cell with the minimum internal resistance in parallel with each target battery cell with the maximum internal resistance, and takes a preset number of parallel samples to construct multiple parallel test groups.

[0015] Furthermore, the test unit includes: a charge and discharge cycle module, which performs cycle tests on multiple parallel test groups according to a preset charging strategy and a preset discharging strategy until the life cycle termination conditions of the battery cells are reached; a recording module, which records the test data of each parallel test group, wherein the test data includes at least: the number of cycles of the battery cells of each parallel test group, the maximum current and the minimum current during the charge and discharge process; and a processing module, which processes the test data of each parallel test group to obtain multiple groups of test data.

[0016] Furthermore, the analysis unit includes: an acquisition submodule, which traverses multiple groups of test data to obtain the number of cycles, maximum current and minimum current of the battery cells of each parallel test group; a third calculation submodule, which calculates the ratio between the maximum current and the minimum current in each parallel test group to obtain the current deviation coefficient of the multiple parallel test groups; an analysis submodule, which determines the internal resistance range of the battery system by comparing and analyzing the relationship between the internal resistance range of the multiple parallel test groups and the number of cycles of the battery cells of the multiple parallel test groups and the current deviation coefficient of the multiple parallel test groups.

[0017] Furthermore, the device also includes: an identification unit, which identifies a target parallel test group corresponding to the internal resistance extreme difference of the battery system from multiple groups of test data; a second acquisition unit, which acquires the corresponding maximum current and minimum current from the target parallel test group; a calculation unit, which calculates the ratio between the maximum current and the minimum current to obtain a target current deviation coefficient; and a determination unit, which determines a charging strategy for the battery system based on the target current deviation coefficient.

[0018] According to another aspect of the present application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute any one of the battery system pairing test methods.

[0019] According to another aspect of the present application, an electronic device is provided, comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include a test method for executing any battery system pairing.

[0020] According to another aspect of the present application, a computer program product is provided, comprising computer instructions, which, when executed by a processor, implement any of the above-mentioned steps of testing the battery system pairing.

[0021] In an embodiment of the present application, the internal resistance data of the target number of battery cells in the battery system grouping are obtained; the battery cells whose internal resistance data are within a preset range are selected to form multiple parallel test groups, wherein each group contains two cells with different internal resistances, and the internal resistance difference is determined by different groupings; the multiple parallel test groups are charged and discharged according to a preset charging strategy and a preset discharging strategy until the end of the life cycle of the battery cells is observed, and multiple groups of test data are obtained; the multiple groups of test data are analyzed to determine the internal resistance range of the battery system grouping, which solves the problem of the long cycle test time of the battery system grouping in the related art, resulting in poor test efficiency of the battery system grouping. In the present application, for different target battery system groupings, battery cells are selected from the batch battery cell data and grouped separately, and the impact of different internal resistance differences on the performance of the battery system is evaluated, providing data support for the internal resistance range standard when the battery system is grouped, and testing is performed at the cell level to avoid system-level testing, thereby achieving the technical effect of improving the test efficiency of the battery system grouping. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0023] Figure 1 A hardware structure block diagram of a computer terminal for implementing a battery system pairing test method is shown;

[0024] Figure 2 is a flow chart of a battery system pairing test method provided in an embodiment of the present application;

[0025] Figure 3 is a flow chart of a method for assembling multiple parallel test groups according to an embodiment of the present application;

[0026] Figure 4 is a flow chart of a charge-discharge cycle test method for multiple parallel test groups provided according to an embodiment of the present application;

[0027] Figure 5 is a flow chart for analyzing multiple groups of test data provided according to an embodiment of the present application;

[0028] Figure 6 is a schematic diagram of a battery system assembly test device provided according to an embodiment of the present application;

[0029] Figure 7 It is a structural block diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0031] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0032] Example 1

[0033] According to an embodiment of the present application, a test method embodiment of a battery system pairing is also provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0034] The method embodiment provided in the first embodiment of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Figure 1 The hardware structure block diagram of a computer terminal (or mobile device) for implementing a battery system pairing test method is shown. Figure 1 As shown, the computer terminal 10 (or mobile device) may include one or more (102a, 102b, ..., 102n are used to illustrate) processors 102 (the processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA), a memory 104 for storing data, and a transmission device 106 for communication functions. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the BUS bus), a network interface, a power supply and / or a camera. It can be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the above electronic device. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations shown.

[0035] It should be noted that the one or more processors 102 and / or other data processing circuits described above may generally be referred to herein as "data processing circuits". The data processing circuits may be embodied in whole or in part as software, hardware, firmware, or any other combination thereof. In addition, the data processing circuit may be a single independent processing module, or may be incorporated in whole or in part into any of the other components in the computer terminal 10 (or mobile device). As described in the embodiments of the present application, the data processing circuit acts as a processor control (e.g., selection of a variable resistor terminal path connected to an interface).

[0036] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the test method of the battery system group in the embodiment of the present application. The processor 102 executes various functional applications and data processing by running the software programs and modules stored in the memory 104, that is, the test method of the battery system group mentioned above is realized. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories may be connected to the computer terminal 10 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0037] The transmission device 106 is used to receive or send data via a network. The specific example of the above network may include a wireless network provided by a communication provider of the computer terminal 10. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0038] The display may be, for example, a touch screen liquid crystal display (LCD) that enables a user to interact with a user interface of the computer terminal 10 (or mobile device).

[0039] Under the above operating environment, this application provides Figure 2 A battery system matching test method is shown. Figure 2 This is a flow chart of a battery system pairing testing method according to Example 1 of the present application.

[0040] Step S201, obtaining internal resistance data of a target number of battery cells in a battery system assembly.

[0041] Optionally, during testing, different projects have different requirements for battery system matching, and the internal resistance data of the battery cells to be tested are different. The above target number refers to the number of battery cells to be tested. In order to make the data statistically significant, the sample size should be large enough, and the target number should be at least 100,000 PCS.

[0042] Step S202 , selecting battery cells whose internal resistance data are within a preset range to form a plurality of parallel test groups, wherein each group includes two battery cells with different internal resistances, and the difference in internal resistance is determined by different group configurations.

[0043] Optionally, each parallel test group is composed of two battery cells with different internal resistances, and the difference in internal resistance of the two battery cells is the internal resistance difference. The above preset range means that different internal resistance extreme ranges will be set for tests of different battery system combinations. For example, for battery system combination A, the preset range of internal resistance difference is 1 to 9 times the standard deviation, and for battery system combination B, the preset range of internal resistance difference is 2 to 6 times the standard deviation. Among them, the standard deviation is calculated from the above internal resistance data, which can help determine the selection range of the test group and ensure that the samples and test results are broadly representative.

[0044] Step S203 , performing charge and discharge cycles on the multiple parallel test groups according to a preset charging strategy and a preset discharging strategy until the life cycle of the battery cells is observed to be terminated, thereby obtaining multiple groups of test data.

[0045] Optionally, different battery system combinations may set different charging strategies and discharging strategies for cycle testing due to factors such as different specific application scenarios. Charging strategy refers to the charging process and parameters, which are used to evaluate the performance of battery cells under charging conditions, and may include parameters such as charging rate, charging voltage, charging time, and charging temperature. Discharging strategy refers to the discharge process and parameters, which are used to evaluate the performance of battery cells under discharge conditions, and may include parameters such as discharge rate, discharge time, discharge depth, and discharge temperature. After setting the charging and discharging strategy, the multiple parallel test groups obtained in step S202 are subjected to charge and discharge cycle tests, and the test data is recorded at the same time until the life cycle of the battery cells of the multiple parallel test groups reaches the termination condition.

[0046] For example, the preset charging strategy is to charge to 100% SOC at a fast charge rate of 2C at a constant temperature of 25°C, and leave the battery cell alone for 30 minutes. The preset discharge strategy is to stabilize the battery cell state at a constant temperature of 25°C and then discharge at a discharge rate of 1C to a cut-off voltage of 3.0V, and then leave the battery cell alone for 30 minutes. According to the above-mentioned charging and discharging strategy, the three parallel test groups (A1, A2, A3) of the battery system group A are charged and discharged cycled until the capacity of the battery cell is observed to decay to less than 80% of the initial capacity, that is, the life cycle is terminated. During the cycle process, the cycle number XA1, the maximum current IA1-1, and the minimum current IA1-2 of the battery cell of the parallel test group A1 are recorded to obtain the test data of the parallel test group A1; the cycle number XA1, the maximum current IA2-1, and the minimum current IA2-2 of the battery cell of the parallel test group A2 are recorded to obtain the test data of the parallel test group A2; the cycle number XA3, the maximum current IA3-1, and the minimum current IA3-2 of the battery cell of the parallel test group A3 are recorded to obtain the test data of the parallel test group A3; multiple groups of test data are obtained based on the parallel test groups A1, A2, and A3.

[0047] Step S204, analyzing multiple groups of test data to determine the internal resistance extremes of the battery system pairing.

[0048] Optionally, the internal resistance range refers to the difference in internal resistance between the battery cell with the largest internal resistance and the battery cell with the smallest internal resistance in the battery system grouping. By comparing and analyzing the test data of parallel test groups with different internal resistance ranges, the relationship between the internal resistance range and the battery system performance is determined, providing an internal resistance range standard for the battery system grouping.

[0049] For example, assuming that the internal resistance range of parallel test group A is 6 ohms and the number of cycles is 20,000, and the internal resistance range of parallel test group B is 8 ohms and the number of cycles is 19,000, based on the fact that the greater the number of cycles, the longer the life of the battery system, it can be determined that the internal resistance range of the battery system is 6 ohms.

[0050] In an embodiment of the present application, the internal resistance data of the target number of battery cells in the battery system grouping are obtained; the battery cells whose internal resistance data are within a preset range are selected to form multiple parallel test groups, wherein each group contains two cells with different internal resistances, and the internal resistance difference is determined by different groupings; the multiple parallel test groups are charged and discharged according to a preset charging strategy and a preset discharging strategy until the end of the life cycle of the battery cells is observed, and multiple groups of test data are obtained; the multiple groups of test data are analyzed to determine the internal resistance range of the battery system grouping, which solves the problem of the long cycle test time of the battery system grouping in the related art, resulting in poor test efficiency of the battery system grouping. In the present application, for different target battery system groupings, battery cells are selected from the batch battery cell data and grouped separately, and the impact of different internal resistance differences on the performance of the battery system is evaluated, providing data support for the internal resistance range standard when the battery system is grouped, and testing is performed at the cell level to avoid system-level testing, thereby achieving the technical effect of improving the test efficiency of the battery system grouping.

[0051] In an optional embodiment, selecting battery cells whose internal resistance data are within a preset range to form multiple parallel test groups includes:

[0052] The first step is to determine the mean value and standard deviation of the internal resistance data based on the internal resistance data of the target number of battery cells in the battery system assembly.

[0053] Optionally, the average value and standard deviation of the internal resistance data of the battery cells in the test sample are calculated to provide a basis for further selection of representative battery cells.

[0054] In the second step, based on the mean value and standard deviation, battery cells with internal resistance data within the preset range are selected to form multiple parallel test groups.

[0055] For example, after statistics on the internal resistance data of battery cells produced by a factory, the average value Rm of the internal resistance data is 1.5mΩ, and the standard deviation Rn is 0.2mΩ. According to the 3σ principle (three standard deviations), it can be preliminarily determined that the battery cells with an internal resistance range of Rm±3Rn are test samples, that is, the selected battery cell internal resistance range should be between 0.9mΩ and 2.1mΩ, covering 99.73% of the battery cells. Within this range, test cells are further selected to construct multiple parallel test groups with extremely different internal resistances.

[0056] Through the above technical solution, representative selection of test cells is achieved, which helps to reduce test time and lower test costs.

[0057] In an optional embodiment, if Figure 3 As shown, based on the average value and standard deviation, battery cells with internal resistance data within a preset range are selected to form multiple parallel test groups including:

[0058] Step S301, calculating the minimum value of the internal resistance data according to the average value and the standard deviation to obtain the minimum internal resistance.

[0059] For example, the average value Rm of the internal resistance data is 1.5mΩ, and the standard deviation Rn is 0.2mΩ. Based on the principle of 3 standard deviations of normal distribution, the minimum internal resistance Rmin is calculated to be 0.9mΩ by the formula minimum internal resistance Rmin=Rm-3Rn.

[0060] Step S302 , selecting target battery cells that differ from the minimum internal resistance by a positive integer multiple of the standard deviation, and determining the maximum internal resistance of each target battery cell, wherein the maximum internal resistance is within a preset range.

[0061] For example, according to the minimum internal resistance Rmin obtained in step S301, 6 groups of target battery cells are selected, and their maximum internal resistances are: Rmax1=Rmin+1Rn=1.1mΩ, Rmax2=Rmin+2Rn=1.3mΩ, Rmax3=Rmin+3Rn=1.5mΩ, Rmax4=Rmin+4Rn=1.7mΩ, Rmax5=Rmin+5Rn=1.9mΩ, Rmax6=Rmin+6Rn=2.1mΩ.

[0062] Step S303 , the battery cell with the smallest internal resistance is assembled in parallel with each target battery cell with the largest internal resistance, and a preset number of parallel samples are taken to construct multiple parallel test groups.

[0063] For example, a battery cell with the smallest internal resistance is connected in parallel with a target battery cell with an internal resistance of Rmax1 to obtain test group 1. A battery cell with the smallest internal resistance is connected in parallel with a target battery cell with an internal resistance of Rmax2 to obtain test group 2. A battery cell with the smallest internal resistance is connected in parallel with a target battery cell with an internal resistance of Rmax3 to obtain test group 3. A battery cell with the smallest internal resistance is connected in parallel with a target battery cell with an internal resistance of Rmax4 to obtain test group 4. A battery cell with the smallest internal resistance is connected in parallel with a target battery cell with an internal resistance of Rmax5 to obtain test group 5; and a battery cell with the smallest internal resistance is connected in parallel with a target battery cell with an internal resistance of Rmax6 to obtain test group 6.

[0064] Multiple parallel samples are taken from each test group 1 to test group 6. The selection of parallel samples follows the same principle, that is, under strictly controlled experimental conditions, independent tests are performed on the same group of battery cells with different internal resistance to ensure the comparability of the data and the reliability of the experimental results.

[0065] For example, in test group 3, three parallel samples were selected for the parallel test group of cells with internal resistances of Rmin (0.900mΩ) and Rmin+3Rn (1.500mΩ) for experiment. Parallel sample 1 is cell 1A with an internal resistance of 0.900mΩ, connected in parallel with another cell with an internal resistance of 1.500mΩ. Parallel sample 2 is cell 1B with an internal resistance of 0.900mΩ, connected in parallel with another cell with an internal resistance of 1.498mΩ. Parallel sample 3 is cell 1C with an internal resistance of 0.900mΩ, connected in parallel with another cell with an internal resistance of 1.502mΩ. In these samples, the internal resistance of the Rmin cell remains consistent, while the internal resistance of the cell connected in parallel with it fluctuates slightly within the target range, in order to simulate the slight differences in the internal resistance of the cells in actual production.

[0066] Through the above technical solution, the battery system group testing method is optimized, the testing time and cost are reduced, and the testing efficiency is improved.

[0067] In an optional embodiment, if Figure 4 As shown, multiple groups of parallel test groups are charged and discharged according to a preset charging strategy and a preset discharging strategy until the life cycle of the battery cell is observed to be terminated, and multiple groups of test data are obtained, including:

[0068] Step S401 , performing cyclic testing on multiple parallel test groups according to a preset charging strategy and a preset discharging strategy until a life cycle termination condition of the battery cell is reached.

[0069] Optionally, the charging strategy and discharging strategy can be preset according to the use environment of the simulated target system. At the same time, during the test, to ensure that the internal resistance of the battery cell is not affected by the temperature, it can be carried out in a constant temperature environment. Cycle charge and discharge until the battery cell reaches the end of life cycle conditions, where the end of life cycle conditions may include the capacity of the battery cell decaying to less than 80% of the initial capacity, the power output capacity of the battery cell is lower than a certain threshold, etc.

[0070] For example, to simulate the actual use environment of the target battery system, the temperature corresponding to the constant temperature environment is selected as 25 degrees Celsius, the charging strategy is to charge at a charging rate of 1C until the battery SOC reaches 80%, and then let the battery cell stand for 1 hour, and the discharging strategy is to discharge at a discharge rate of 0.5C until the battery voltage drops to 3.0V, and then stand for 1 hour, and the above charging strategy and discharging strategy are cycled until the life cycle of the battery cell ends.

[0071] Step S402, recording the test data of each parallel test group, wherein the test data at least includes: the number of cycles of the battery cells of each parallel test group, and the maximum current and the minimum current during the charge and discharge process.

[0072] Optionally, after each charge and discharge cycle, the maximum current and minimum current of the battery cells of the parallel test group during the charge and discharge process, as well as the number of cycles are recorded.

[0073] For example, assuming that three parallel samples are taken for each parallel test group, for test group 1, the test records of parallel sample 1A, parallel sample 1B, and parallel sample 1C are recorded respectively. The number of cycles of parallel sample 1A is X1A, and the maximum current A1A-1 and the minimum current A1A-2 during the charge and discharge process. The number of cycles of parallel sample 1B is X1B; the maximum current A1B-1 and the minimum current A1B-2 during the charge and discharge process. The number of cycles of parallel sample 1C is X1C; the maximum current A1C-1 and the minimum current A1C-2 during the charge and discharge process. And so on, record the test data of each parallel test group.

[0074] Step S403, processing the test data of each parallel test group to obtain multiple groups of test data.

[0075] Optionally, processing the test data of each parallel test group means calculating the test data of multiple parallel samples in each parallel test group according to a statistical analysis method to obtain a test data as the final data of each parallel test group. The statistical analysis method may include: median, mode, mean, etc., which are not limited in this application.

[0076] For example, in step S402 , the number of cycles X1A of the parallel sample 1A is 4000 times, the maximum current A1A-1 during the charge and discharge process is 2.01A, and the minimum current A1A-2 is 1.98A.

[0077] The number of cycles X1B of parallel sample 1B is 3950 times; the maximum current A1B-1 during the charge and discharge process is 2.00A; and the minimum current A1B-2 is 1.99A.

[0078] The number of cycles X1C of the parallel sample 1C is 4050 times; the maximum current A1C-1 during the charge and discharge process is 2.02A; the minimum current A1C-2 is 1.97A.

[0079] Taking the average of the test data of the above three parallel samples, we can obtain the number of cycles of each parallel test group: X1=(4000+3950+4050) / 3=4000. Similarly, the maximum current of each parallel test group is 2.00A, and the minimum current of each parallel test group is 1.98A.

[0080] For test group 1, record the number of cycles as X1, the maximum current as A1-1, and the minimum current as A1-2; for test group 2, record the number of cycles as X2, the maximum current as A2-1, and the minimum current as A2-2; and so on, record the data of all test groups.

[0081] Through the above technical solution, the performance of parallel test groups with different internal resistance extremes under a preset charging and discharging strategy can be systematically evaluated at the battery cell level, avoiding system-level testing and thus improving test efficiency.

[0082] In an optional embodiment, if Figure 5 As shown, by analyzing multiple groups of test data, it is determined that the internal resistance range of the battery system matching group includes:

[0083] Step S501, traverse multiple groups of test data to obtain the number of cycles, maximum current and minimum current of each group of parallel test group battery cells.

[0084] For example, test group 1 (0.9mΩ battery cell and 1.1mΩ battery cell in parallel): the number of cycles X1 is 4500 times, the maximum current A1-1 is 2.1A, and the minimum current A1-2 is 2.0A.

[0085] Test group 2 (0.9mΩ battery cell and 1.3mΩ battery cell in parallel): the number of cycles X2 is 4000 times, the maximum current A2-1 is 2.2A, and the minimum current A2-2 is 1.9A.

[0086] Test group 3 (0.9mΩ battery cell and 1.3mΩ battery cell in parallel): the number of cycles X3 is 3500 times, the maximum current A3-1 is 2.3A, and the minimum current A3-2 is 1.8A.

[0087] Test group 4 (0.9mΩ battery cell and 1.5mΩ battery cell in parallel): the number of cycles X4 is 2800 times, the maximum current A4-1 is 2.4A, and the minimum current A4-2 is 1.6A.

[0088] Test group 5 (0.9mΩ battery cell and 1.7mΩ battery cell in parallel): the number of cycles X5 is 2000 times, the maximum current A5-1 is 2.5A, and the minimum current A5-2 is 1.4A.

[0089] Test group 6 (0.9mΩ battery cell and 1.9mΩ battery cell in parallel): the number of cycles X6 is 1500 times, the maximum current A6-1 is 2.6A, and the minimum current A6-2 is 1.2A.

[0090] Step S502, calculating the ratio between the maximum current and the minimum current in each parallel test group to obtain the current deviation coefficients of the multiple parallel test groups.

[0091] For example, based on each group of test data in the case of step S501, the current deviation coefficient y1 of test group 1 is calculated to be A1-1 / A1-2=2.1 / 2.0=1.05. Similarly, the current deviation coefficient y2 of test group 2 is 1.158, the current deviation coefficient y3 of test group 3 is 1.278, the current deviation coefficient y4 of test group 4 is 1.5, the current deviation coefficient y5 of test group 5 is 1.786, and the current deviation coefficient y6 of test group 6 is 2.167.

[0092] Step S503, determining the internal resistance range of the battery system pairing by comparing and analyzing the relationship between the internal resistance range of the multiple parallel test groups, the number of cycles of the battery cells of the multiple parallel test groups, and the current deviation coefficient of the multiple parallel test groups.

[0093] Optionally, the current deviation coefficient is a parameter used to measure the degree of imbalance in the current distribution of each battery cell in a parallel battery system during charging or discharging. In an ideal parallel battery pack, all batteries should carry the same current to ensure the performance and life of the battery pack. However, in actual situations, due to slight differences in factors such as the internal resistance, capacity, and health status of each battery cell, their current distribution during charging and discharging will be different. This unbalanced current distribution, especially when the parallel battery pack is charged with a large current (such as fast charging), may cause some battery cells to be overcharged or over-discharged, thereby accelerating their aging and affecting the performance and safety of the entire battery pack.

[0094] For example, through the data analysis of the cases in steps S501 and S502, it can be seen that the number of cycles of test group 1 (Rmax1=1.1mΩ) is the highest, reaching 4500 times, and the current deviation coefficient y1 is 1.05, which is relatively small. Under a small internal resistance difference, the battery cell can maintain a longer cycle life and the current distribution is more balanced. Based on the above data, we can determine that a group of internal resistance difference test groups with better battery life and performance is the parallel matching group of test group 1, which not only ensures a longer cycle life, but also controls the current deviation coefficient within a smaller range, which is conducive to the safe and stable operation of the battery under the fast charging strategy. Correspondingly, the internal resistance range of the battery system matching group can be determined to be 0.2mΩ.

[0095] The above technical solution helps to set reasonable internal resistance range standards for battery packs, ensure that the battery system has stable and efficient performance in long-term use, extend battery life, and reduce testing costs and time.

[0096] In an optional embodiment, after analyzing multiple groups of test data to determine the internal resistance extreme difference of the battery system pairing, the method further includes:

[0097] The first step is to identify the target parallel test group corresponding to the extreme difference in internal resistance of the battery system from multiple groups of test data.

[0098] For example, the internal resistance range of the battery system pairing determined in step S501 is 0.2 mΩ, and the corresponding test group 1 is the target parallel test group.

[0099] The second step is to obtain the corresponding maximum current and minimum current from the target parallel test group.

[0100] For example, the maximum current A1 - 1 of the parallel test group 1 is 2.1A, and the minimum current A1 - 2 is 2.0A.

[0101] The third step is to calculate the ratio between the maximum current and the minimum current to obtain the target current deviation coefficient.

[0102] For example, the current deviation coefficient y1 of test group 1 is A1-1 / A1-2=2.1 / 2.0=1.05.

[0103] The fourth step is to determine the charging strategy for the battery system based on the target current deviation coefficient.

[0104] Optionally, if the current deviation coefficient y of a parallel battery pack is set to 1.05 during fast charging, this means that the current of any battery cell unit will not exceed 1.05 times the current of other battery cell units. This helps to maintain relative current balance during fast charging and prevent certain battery cell units from premature aging or damage due to excessive current.

[0105] For example, when the current deviation coefficient y is 1.05, the fast charging strategy that can be set is: before fast charging, pre-charge at a rate of 0.5C until the state of charge (SOC) of the battery cell reaches 30%. During the pre-charging process, continuously monitor the current of each battery cell to ensure that there is no abnormal current distribution. When the SOC of all batteries reaches 30%, start fast charging at a maximum charging rate of 2C, but adopt a strategy of dynamically adjusting the current. Monitor the charging current and voltage of each battery cell in real time, as well as the total current of the battery pack. If the current of any battery cell exceeds 1.05 times the current of other batteries, that is, the current deviation coefficient y exceeds 1.05, immediately reduce the total charging current until the current deviation coefficient y of all batteries returns to below 1.05. When the battery cell SOC is close to 80%, switch to constant voltage charging mode and gradually reduce the charging current until it is fully charged. During the constant voltage charging stage, continue to monitor the current deviation coefficient y to ensure that it does not exceed 1.05. After charging to 100% SOC, let the cell sit for 15 minutes to allow the charge distribution inside the cell to stabilize.

[0106] By setting a reasonable internal resistance range standard and controlling the current deviation coefficient in the battery system through the above technical solution, it can be ensured that under the fast charging strategy, the current deviation of all battery cells will not exceed the range allowed by their safety and performance. This helps to prevent overcharging or current deviation during fast charging, avoid excessive stress on battery cells, thereby extending the cycle life of the battery system and improving the overall performance and safety of the battery system.

[0107] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0108] Example 2

[0109] The present application also provides a battery system pairing test device. It should be noted that the battery system pairing test device of the present application embodiment can be used to execute the battery system pairing test method provided in the present application embodiment. The battery system pairing test device provided in the present application embodiment is introduced below.

[0110] According to an embodiment of the present application, a device for implementing the above-mentioned battery system pairing test method is also provided, such as Figure 6 As shown, the device includes: a first acquisition unit 601, an assembly unit 602, a testing unit 603, and an analysis unit 604.

[0111] Specifically, the first acquisition unit 601 is used to obtain the internal resistance data of a target number of battery cells in the battery system grouping; the grouping unit 602 is used to select battery cells whose internal resistance data is within a preset range to form a plurality of parallel test groups, wherein each group contains two cells with different internal resistances, and the internal resistance difference is determined by different groupings; the test unit 603 is used to perform charge and discharge cycles on the plurality of parallel test groups according to a preset charging strategy and a preset discharging strategy until the end of the life cycle of the battery cells is observed, thereby obtaining a plurality of groups of test data; the analysis unit 604 is used to analyze the plurality of groups of test data to determine the extreme difference of the internal resistance of the battery system grouping.

[0112] The test device for battery system grouping provided in the embodiment of the present application obtains the internal resistance data of a target number of battery cells in the battery system grouping through a first acquisition unit 601; the grouping unit 602 selects battery cells whose internal resistance data is within a preset range to form a plurality of parallel test groups, wherein each group includes two cells with different internal resistances, and the difference in internal resistance is determined by different groupings; the test unit 603 performs charge and discharge cycles on the plurality of parallel test groups according to a preset charging strategy and a preset discharging strategy until the life cycle of the battery cells is observed to be terminated, thereby obtaining a plurality of groups of test data; the analysis unit 604 analyzes the plurality of groups of test data to determine the internal resistance extreme of the battery system grouping, thereby solving the problem in the related art that the battery system grouping whole package cycle test time is long, resulting in poor test efficiency of the battery system grouping, thereby avoiding system-level testing, and achieving the technical effect of improving the test efficiency of the battery system grouping.

[0113] Optionally, in the battery system grouping test device provided in the embodiment of the present application, the grouping unit 602 includes: a calculation module, which determines the average value and standard deviation of the internal resistance data based on the internal resistance data of a target number of battery cells in the battery system grouping; and a grouping module, which selects battery cells whose internal resistance data are within a preset range based on the average value and the standard deviation to form multiple parallel test groups.

[0114] Optionally, in the battery system grouping test device provided in the embodiment of the present application, the grouping module includes: a first calculation submodule, which calculates the minimum value of the internal resistance data according to the average value and the standard deviation to obtain the minimum internal resistance; a second calculation submodule, which selects target battery cells that differ from the minimum internal resistance by a positive integer multiple of the standard deviation, and determines the maximum internal resistance of each target battery cell, wherein the maximum internal resistance is within a preset range; and a grouping submodule, which groups the battery cell with the minimum internal resistance in parallel with each target battery cell with the maximum internal resistance, and takes a preset number of parallel samples to construct multiple parallel test groups.

[0115] Optionally, in the battery system assembly test device provided in the embodiment of the present application, the test unit 603 includes: a charge and discharge cycle module, which performs cycle tests on multiple parallel test groups according to a preset charging strategy and a preset discharging strategy until the life cycle termination conditions of the battery cells are reached; a recording module, which records the test data of each parallel test group, wherein the test data includes at least: the number of cycles of the battery cells of each parallel test group, the maximum current and the minimum current during the charge and discharge process; and a processing module, which processes the test data of each parallel test group to obtain multiple groups of test data.

[0116] Optionally, in the test device for the battery system grouping provided in the embodiment of the present application, the analysis unit 604 includes: an acquisition submodule, traversing multiple groups of test data, and acquiring the number of cycles, maximum current and minimum current of the battery cells of each parallel test group; a third calculation submodule, calculating the ratio between the maximum current and the minimum current in each parallel test group, and obtaining the current deviation coefficients of the multiple parallel test groups; an analysis submodule, determining the internal resistance range of the battery system grouping by comparing and analyzing the relationship between the internal resistance range of the multiple parallel test groups and the number of cycles of the battery cells of the multiple parallel test groups and the current deviation coefficients of the multiple parallel test groups.

[0117] Optionally, in the battery system grouping test device provided in the embodiment of the present application, the device also includes: an identification unit, which identifies a target parallel test group corresponding to the internal resistance range of the battery system group from multiple groups of test data; a second acquisition unit, which acquires the corresponding maximum current and minimum current from the target parallel test group; a calculation unit, which calculates the ratio between the maximum current and the minimum current to obtain a target current deviation coefficient; and a determination unit, which determines a charging strategy for the battery system based on the target current deviation coefficient.

[0118] It should be noted that the first acquisition unit 601, assembly unit 602, test unit 603, and analysis unit 604 described above correspond to steps S201 to S204 in Example 1, and the four units and corresponding steps implement the same examples and application scenarios, but are not limited to the contents disclosed in the above-mentioned Example 1. It should be noted that the above-mentioned modules or units may be hardware components or software components stored in a memory (e.g., memory 104) and processed by one or more processors (e.g., processors 102a, 102b, ..., 102n), and the above-mentioned modules may also be part of a device and may be run in the computer terminal 10 provided in Example 1.

[0119] Example 3

[0120] An embodiment of the present application may provide an electronic device, Figure 7 is a structural block diagram of an electronic device according to an embodiment of the present application. Figure 7As shown, the electronic device may include: one or more ( Figure 7 (only one is shown) processor 702, memory 704, storage controller, and peripheral interface, wherein the peripheral interface is connected to the radio frequency module, audio module and display.

[0121] Among them, the memory can be used to store software programs and modules, such as program instructions / modules corresponding to the methods and devices in the embodiments of the present application, and the processor executes various functional applications and data processing by running the software programs and modules stored in the memory, that is, realizing the above-mentioned method. The memory may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include a memory remotely arranged relative to the processor, and these remote memories may be connected to the terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0122] The processor can call the information and application programs stored in the memory through the transmission device to perform the following steps: obtain the internal resistance data of a target number of battery cells in the battery system grouping; select the battery cells whose internal resistance data are within a preset range to form multiple parallel test groups, wherein each group contains two cells with different internal resistances, and the internal resistance difference is determined by different groupings; perform charge and discharge cycles on the multiple parallel test groups according to a preset charging strategy and a preset discharging strategy until the end of the life cycle of the battery cells is observed, thereby obtaining multiple groups of test data; and analyze the multiple groups of test data to determine the internal resistance extremes of the battery system grouping.

[0123] The processor can call the information and application programs stored in the memory through the transmission device to perform the following steps: selecting battery cells whose internal resistance data are within a preset range to form multiple parallel test groups, including: determining the average value and standard deviation of the internal resistance data based on the internal resistance data of a target number of battery cells in the battery system grouping; based on the average value and standard deviation, selecting battery cells whose internal resistance data are within a preset range to form multiple parallel test groups.

[0124] The processor can call the information and application program stored in the memory through the transmission device to perform the following steps: based on the average value and the standard deviation, select the battery cells whose internal resistance data is within a preset range to form multiple parallel test groups, including: according to the average value and the standard deviation, calculate the minimum value of the internal resistance data to obtain the minimum internal resistance; select the target battery cells that differ from the minimum internal resistance by a positive integer multiple of the standard deviation, and determine the maximum internal resistance of each target battery cell, wherein the maximum internal resistance is within a preset range; and parallel-assemble the battery cell with the minimum internal resistance with each target battery cell with the maximum internal resistance, and take a preset number of parallel samples to construct multiple parallel test groups.

[0125] The processor can call the information and application programs stored in the memory through the transmission device to perform the following steps: perform charge and discharge cycles on multiple parallel test groups according to a preset charging strategy and a preset discharging strategy until the life cycle of the battery cell is observed to be terminated, and obtain multiple groups of test data including: perform cycle tests on multiple parallel test groups according to a preset charging strategy and a preset discharging strategy until the life cycle termination conditions of the battery cell are reached; record the test data of each parallel test group, wherein the test data at least includes: the number of cycles of the battery cell of each parallel test group, the maximum current and the minimum current during the charging and discharging process; and process the test data of each parallel test group to obtain multiple groups of test data.

[0126] The processor can call the information and application programs stored in the memory through the transmission device to perform the following steps: analyzing multiple groups of test data to determine the internal resistance range of the battery system grouping, including: traversing multiple groups of test data to obtain the number of cycles, maximum current and minimum current of each group of parallel test groups of battery cells; calculating the ratio between the maximum current and the minimum current in each group of parallel test groups to obtain the current deviation coefficient of multiple parallel test groups; by comparing and analyzing the relationship between the internal resistance range of multiple parallel test groups and the number of cycles of multiple parallel test groups of battery cells and the current deviation coefficient of multiple parallel test groups, the internal resistance range of the battery system grouping is determined.

[0127] The processor can call the information and application programs stored in the memory through the transmission device to perform the following steps: after analyzing multiple groups of test data and determining the internal resistance range of the battery system group, the method also includes: identifying the target parallel test group corresponding to the internal resistance range of the battery system group from the multiple groups of test data; obtaining the corresponding maximum current and minimum current from the target parallel test group; calculating the ratio between the maximum current and the minimum current to obtain the target current deviation coefficient; and determining the charging strategy for the battery system based on the target current deviation coefficient.

[0128] By adopting the embodiment of the present application, a scheme for testing battery system grouping is provided. By obtaining the internal resistance data of the target number of battery cells in the battery system grouping; selecting the battery cells whose internal resistance data are within the preset range to form multiple parallel test groups, wherein each group contains two cells with different internal resistances, and the internal resistance difference is determined by different groupings; charging and discharging the multiple parallel test groups according to the preset charging strategy and the preset discharging strategy until the end of the life cycle of the battery cells is observed, and multiple groups of test data are obtained; analyzing the multiple groups of test data to determine the internal resistance extreme difference of the battery system grouping, the problem of long cycle test time of the battery system grouping in the related technology, resulting in poor efficiency of battery system grouping test, is solved. In the present application, for different target battery system groups, representative battery cells are selected from the batch battery cell data and grouped separately, and the impact of different internal resistance differences on the performance of the battery system is evaluated, providing data support for the internal resistance extreme difference standard when the battery system is grouped, and testing is performed at the cell level, avoiding system-level testing, thereby achieving the technical effect of improving the efficiency of battery system grouping test.

[0129] It can be understood by those skilled in the art that Figure 7 The structure shown is for illustration only, and the electronic device may also be a smart phone (such as an Android phone, an iOS phone, etc.), a tablet computer, a PDA, a mobile Internet device (Mobile Internet Devices, MID), a PAD, or other terminal devices. Figure 7 The structure of the electronic device is not limited. Figure 7 More or fewer components (such as network interfaces, display devices, etc.) shown in, or having Figure 7 Different configurations shown.

[0130] A person of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing the hardware related to the terminal device through a program, and the program can be stored in a computer-readable storage medium, and the storage medium may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0131] Example 4

[0132] The embodiment of the present application further provides a storage medium. Optionally, in this embodiment, the storage medium can be used to store the program code executed by the battery system pairing test method provided in the first embodiment.

[0133] Optionally, in this embodiment, the above storage medium may be located in any computer terminal in a computer terminal group in a computer network, or in any mobile terminal in a mobile terminal group.

[0134] The present application also provides a computer program product, which, when executed on a data processing device, is suitable for executing the program steps of the battery system matching test method.

[0135] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0136] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0137] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, 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 units or modules, which can be electrical or other forms.

[0138] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0139] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0140] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0141] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A battery system assembly test method, characterized in that: include: Obtain the internal resistance data of the target number of battery cells in the battery system group; Selecting battery cells whose internal resistance data are within a preset range to form multiple parallel test groups, wherein each group includes two battery cells with different internal resistances, and the difference in internal resistance is determined by different group configurations; Performing charge and discharge cycles on the multiple parallel test groups according to a preset charging strategy and a preset discharging strategy until the life cycle of the battery cells is observed to be terminated, thereby obtaining multiple groups of test data; The multiple groups of test data are analyzed to determine the internal resistance extremes of the battery system pairing.

2. The method according to claim 1, characterized in that Selecting battery cells whose internal resistance data is within a preset range to form multiple parallel test groups includes: Determining the mean value and standard deviation of the internal resistance data according to the internal resistance data of the target number of battery cells in the battery system combination; According to the average value and the standard deviation, the battery cells whose internal resistance data are within a preset range are selected to form a plurality of parallel test groups.

3. The method according to claim 2, characterized in that According to the average value and the standard deviation, selecting battery cells whose internal resistance data are within a preset range to form multiple parallel test groups includes: Calculate the minimum value of the internal resistance data according to the average value and the standard deviation to obtain the minimum internal resistance; Selecting target battery cells that differ from the minimum internal resistance by a positive integer multiple of the standard deviation, and determining a maximum internal resistance of each of the target battery cells, wherein the maximum internal resistance is within the preset range; The battery cell with the smallest internal resistance is assembled in parallel with each target battery cell with the largest internal resistance, and a preset number of parallel samples are taken to construct multiple parallel test groups.

4. The method according to claim 1, characterized in that: The plurality of parallel test groups are charged and discharged according to a preset charging strategy and a preset discharging strategy until the life cycle of the battery cell is observed to be terminated, and a plurality of test data are obtained, including: Performing cycle tests on the plurality of parallel test groups according to a preset charging strategy and a preset discharging strategy until a life cycle termination condition of the battery cell is reached; Recording the test data of each parallel test group, wherein the test data at least includes: the number of cycles of the battery cells of each parallel test group, the maximum current and the minimum current during the charge and discharge process; The test data of each parallel test group is processed to obtain the multiple groups of test data.

5. The method according to claim 1, characterized in that: Analyzing the multiple groups of test data to determine the internal resistance range of the battery system pairing includes: Traversing the multiple groups of test data, obtaining the number of cycles, maximum current and minimum current of each group of parallel test group battery cells; Calculate the ratio between the maximum current and the minimum current in each parallel test group to obtain the current deviation coefficient of the multiple parallel test groups; The internal resistance range of the battery system assembly is determined by comparing and analyzing the relationship between the internal resistance range of multiple parallel test groups, the number of cycles of the battery cells of the multiple parallel test groups, and the current deviation coefficient of the multiple parallel test groups.

6. The method according to claim 5, characterized in that After analyzing the plurality of test data sets to determine the internal resistance extreme difference of the battery system pairing, the method further includes: Identifying, from the plurality of test data sets, a target parallel test set corresponding to an internal resistance extreme difference of the battery system set; Obtaining the corresponding maximum current and minimum current from the target parallel test group; Calculating a ratio between the maximum current and the minimum current to obtain a target current deviation coefficient; A charging strategy for the battery system is determined according to the target current deviation coefficient.

7. A battery system assembly test device, characterized in that: include: A first acquisition unit is used to acquire internal resistance data of a target number of battery cells in a battery system assembly; A grouping unit, used for selecting battery cells whose internal resistance data are within a preset range to form a plurality of parallel test groups, wherein each group includes two battery cells with different internal resistances, and the difference in internal resistance is determined by different groupings; A test unit, used to perform charge and discharge cycles on the multiple parallel test groups according to a preset charging strategy and a preset discharging strategy until the life cycle of the battery cells is observed to be terminated, thereby obtaining multiple groups of test data; The analysis unit is used to analyze the multiple groups of test data to determine the internal resistance extreme difference of the battery system combination.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored executable program, wherein when the executable program is run, the device where the computer-readable storage medium is located is controlled to execute the battery system group testing method according to any one of claims 1 to 6.

9. An electronic device, characterized in that: include: A memory storing an executable program; A processor is used to run the program, wherein the program, when running, executes the method for testing the battery system pairing as described in any one of claims 1 to 6.

10. A computer program product comprising computer instructions, characterized in that: When the computer instructions are executed by a processor, the steps of the method for testing the battery system pairing described in any one of claims 1 to 6 are implemented.

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