A battery cell charging method, device and electronic device

Abstract

The present invention discloses a battery cell charging method, device and electronic device, the method comprising: charging a plurality of battery cells based on a preset cut-off condition, and predicting the actual battery cell capacity of each battery cell according to the charging process; calculating the charging time required for each battery cell to reach a preset SOC based on the actual battery cell capacity of each battery cell and the capacity already charged in each battery cell, the preset SOC being the SOC relative to the actual battery cell capacity of each battery cell; charging each battery cell according to the charging time corresponding to each battery cell. The technical solution provided by the present invention can further improve the consistency of battery cell voltage while ensuring the shipping efficiency.

Description

Technical Field

[0001] The present invention relates to the field of batteries, and in particular to a battery cell charging method, device and electronic equipment. Background Art

[0002] As the core part of new energy products such as electric vehicles, the battery pack is composed of hundreds or more battery cells connected in series. When the battery pack is working, a commonly used control strategy is: when the voltage of a single battery cell reaches the upper or lower voltage limit, in order to avoid overcharging and over-discharging, the control strategy of the battery pack will stop the operation of the entire battery pack when a certain battery cell is terminated, thus causing other batteries that have not reached the upper and lower voltage limits to terminate their operation. Therefore, the consistency of the battery cell voltage in the battery pack directly affects the battery pack capacity, life attenuation, reliability characteristics, etc.

[0003] When the battery pack leaves the factory, each cell will be pre-charged with a portion of electricity. The percentage of the pre-charged capacity of each cell to the total capacity is called the shipping SOC (State Of Charge). The existing technology usually charges each battery with the same capacity value. Since the total capacity value of each cell is different, the shipping SOC of each cell must be different, and the voltage consistency of the cell is closely related to the shipping SOC consistency. In order to improve the consistency of the cell voltage in the battery pack, the existing technology usually divides the cells into batches, and packs the large-capacity cells together and the small-capacity cells together, so that the shipping SOC of the cells can be aligned as much as possible when the battery is actually used, that is, the cell voltage can be aligned as much as possible, but the actual use effect of this method is unsatisfactory.

[0004] To address this problem, if the actual capacity of each cell is known, then the product of the actual capacity of each cell and the shipped SOC can be calculated to get the actual capacity of each cell, which can also ensure the alignment of the cell voltages. However, in actual usage scenarios, each cell needs to be fully charged and then discharged to obtain the actual capacity of the cell, and then each cell needs to be charged separately, which seriously affects the shipping efficiency. Therefore, how to further improve the consistency of cell voltage while ensuring shipping efficiency is an urgent problem to be solved. Summary of the invention

[0005] In view of this, embodiments of the present invention provide a battery cell charging method, device and electronic device, thereby improving the consistency of battery cell voltage.

[0006] According to a first aspect, an embodiment of the present invention provides a battery cell charging method, the method comprising: charging a plurality of battery cells based on a preset cutoff condition, and predicting an actual battery cell capacity of each battery cell according to the charging process; calculating a charging time required for each battery cell to reach a preset SOC based on the actual battery cell capacity of each battery cell and the capacity already charged in each battery cell, wherein the preset SOC is the SOC relative to the actual battery cell capacity of each battery cell; and charging each battery cell according to the charging time corresponding to each battery cell.

[0007] Optionally, the method of charging a plurality of battery cells based on a preset cutoff condition and predicting an actual battery cell capacity of each battery cell according to the charging process includes: charging a current battery cell, and when the current battery cell reaches the preset cutoff condition, recording a current battery charging parameter corresponding to the current battery cell; and determining the actual battery cell capacity of the current battery cell from a relationship table of battery cell capacity and battery charging parameters based on the current battery charging parameter.

[0008] Optionally, the relationship table between the cell capacity and the battery charging parameters is obtained by: charging a plurality of cell samples with different and known capacities according to the preset cutoff condition; and creating the relationship table between the cell capacity and the battery charging parameters according to the charging process.

[0009] Optionally, the preset cutoff condition is a preset time length, and creating a relationship table between battery cell capacity and battery charging parameters according to the charging process includes: when the charging time of each of the battery cell samples reaches the preset time length, recording the current corresponding open circuit voltage of each battery cell sample, and using the open circuit voltage as the battery charging parameter; creating a relationship table between the battery cell capacity and the corresponding open circuit voltage of each battery cell sample as the relationship table between the battery cell capacity and the battery charging parameters.

[0010] Optionally, the preset cutoff condition is a preset voltage value, and creating a relationship table between battery cell capacity and battery charging parameters according to the charging process includes: when the charging voltage of each battery cell sample reaches the preset voltage value, recording the corresponding charged capacity of each battery cell sample, and using the charged capacity as the battery charging parameter; creating a relationship table between the battery cell capacity and the corresponding charged capacity of each battery cell sample as the relationship table between the battery cell capacity and the battery charging parameters.

[0011] Optionally, the charging time required for each battery cell to reach a preset SOC based on the actual battery capacity of each battery cell and the capacity that has been charged in each battery cell includes: determining the capacity that needs to be charged in the current battery cell based on the product of the actual battery capacity of the current battery cell and the preset SOC; calculating the difference between the capacity that needs to be charged in the current battery cell and the capacity that has been charged in the current battery cell, to obtain the capacity that has not been charged in the current battery cell; and determining the charging time required for the current battery cell to reach the preset SOC based on the ratio of the capacity that has not been charged in the current battery cell to the charging current.

[0012] Optionally, the method further includes: dividing each charged battery cell into multiple groups based on the actual battery cell capacity of each battery cell, wherein the actual battery cell capacity of the battery cells in the same group all fall within the same preset range; and selecting a battery pack from the same group of battery cells.

[0013] According to the second aspect, an embodiment of the present invention provides a battery cell charging device, which includes: a capacity prediction unit, which is used to charge multiple battery cells based on preset cutoff conditions, and predict the actual battery cell capacity of each battery cell according to the charging process; a time determination unit, which is used to calculate the charging time required for each battery cell to reach a preset SOC based on the actual battery cell capacity of each battery cell and the capacity already charged in each battery cell, and the preset SOC is the SOC relative to the actual battery cell capacity of each battery cell; a post-charging unit, which is used to charge each battery cell according to the charging time corresponding to each battery cell.

[0014] According to the third aspect, an embodiment of the present invention provides an electronic device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the method described in the first aspect or any optional implementation manner of the first aspect by executing the computer instructions.

[0015] According to a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the method described in the first aspect or any optional implementation manner of the first aspect.

[0016] The technical solution provided by this application has the following advantages:

[0017] The technical solution provided by the present application is to ensure the consistency of the voltage of each battery cell when the battery is shipped, so as to determine the target to ensure that the SOC of each battery cell in the package is consistent when the battery is shipped. Therefore, when charging each battery cell, firstly, a plurality of batteries are slowly charged with a constant small current through a preset cutoff condition, so as to accurately predict the actual battery cell capacity of each battery cell. If the SOC of each battery cell is made consistent, it will take a longer charging time for a large-capacity battery cell to charge to the preset SOC, and a shorter charging time for a small-capacity battery cell. Therefore, the remaining charging time for each battery cell to charge to the preset SOC can be accurately calculated based on the actual battery cell capacity of each battery cell and the capacity that has been charged. Then, charging will continue according to the charging time calculated for each battery cell. When the charging time of each battery cell is reached, it can be ensured that the shipping SOC of each battery cell is consistent, and all are the preset SOC, thereby improving the consistency of the voltage of each battery cell under the premise of ensuring the shipping efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The features and advantages of the present invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the present invention in any way. In the accompanying drawings:

[0019] Figure 1 A schematic diagram showing the steps of a battery cell charging method in one embodiment of the present invention is shown;

[0020] Figure 2 The dV / dQ curve of a lithium iron phosphate battery cell in one embodiment of the present invention is shown;

[0021] Figure 3 A diagram showing the relationship between constant voltage charging capacity and cell capacity in one embodiment of the present invention is shown;

[0022] Figure 4 A diagram showing the relationship between constant current charging voltage and cell capacity in one embodiment of the present invention is shown;

[0023] Figure 5 A schematic structural diagram of a battery cell charging device in one embodiment of the present invention is shown;

[0024] Figure 6 A schematic structural diagram of an electronic device in one embodiment of the present invention is shown. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0026] See also Figure 1 In one embodiment, a method for charging a battery cell comprises the following steps:

[0027] Step S101: charging a plurality of battery cells based on a preset cutoff condition, and predicting the actual battery cell capacity of each battery cell according to the charging process.

[0028] Step S102: Calculate the charging time required for each battery cell to reach a preset SOC based on the actual battery cell capacity of each battery cell and the capacity already charged in each battery cell. The preset SOC is the SOC relative to the actual battery cell capacity of each battery cell.

[0029] Step S103: charging each battery cell according to the charging time corresponding to each battery cell.

[0030] Specifically, in order to ensure the consistency of the voltage of each battery cell when the battery is shipped, the goal is to ensure that the SOC of each battery cell in the package is consistent when the battery is shipped. In actual production, the actual cell capacity of each battery is different. For example, if the rated capacity is 100Ah, the actual cell capacity may be 100Ah, 101Ah, 102AH, 101.3Ah, etc. If you want to align the voltage of each battery cell, the better way is to align the shipping SOC of each battery cell. For example: if the preset SOC is 40%, then the 100Ah, 101Ah and other batteries need to be charged with 40% of their own capacity, such as 100Ah batteries need to be charged with 40Ah, and 101Ah batteries need to be charged with 40.4Ah. However, when measuring the capacity of a battery cell, the prior art needs to fully charge the battery cell first and then discharge it, and count the discharge amount. The amount of electricity discharged is the battery cell capacity. If this operation is performed on each battery cell before shipment in order to ensure the consistency of battery cell voltage, it will result in extremely low power efficiency.

[0031] Therefore, in this embodiment, the battery cell is first discharged to the minimum voltage (i.e., empty) according to the specified current, and a 1 / 3C current ratio can be selected. Then, each battery cell is charged, and multiple batteries are slowly charged with a constant small current during the charging process, and the charging is stopped when the preset cut-off condition is reached, so as to accurately predict the actual battery cell capacity of each battery cell during the charging process. If the SOC of each battery cell is consistent, it takes a longer charging time for a large-capacity battery cell to be charged to the preset SOC, and a shorter charging time for a small-capacity battery cell. Therefore, the remaining charging time for each battery cell to be charged to the preset SOC can be accurately calculated based on the actual battery cell capacity of each battery cell and the capacity that has been charged. Then, the charging is continued according to the charging time calculated for each battery cell. When the charging time of each battery cell is reached, the shipping SOC of each battery cell can be guaranteed to be consistent, and all are the preset SOC, thereby improving the consistency of the voltage of each battery cell while ensuring the shipping efficiency.

[0032] Specifically, in one embodiment, the above step S101 specifically includes the following steps:

[0033] Step 1: Charge the current battery cell, and when the current battery cell reaches a preset cutoff condition, record the current battery charging parameters corresponding to the current battery cell.

[0034] Step 2: Based on the current battery charging parameters, determine the actual cell capacity of the current cell from a relationship table between cell capacity and battery charging parameters.

[0035] Specifically, in this embodiment, a relationship table between cell capacity and battery charging parameters is created in advance, and the battery charging parameters are the corresponding battery charging parameters when the cell starts charging from the lowest voltage to the preset cut-off condition. Therefore, during the charging process of the current cell, when the current cell reaches the preset cut-off condition, the current battery charging parameters of the cell are recorded, and then the corresponding table is looked up to retrieve the cell capacity corresponding to the current battery charging parameters in the relationship table between cell capacity and battery charging parameters, that is, the actual cell capacity predicted by the current cell, thereby achieving the acquisition of the actual cell capacity of the cell during the charging process.

[0036] In this embodiment, the steps of creating a relationship table between battery cell capacity and battery charging parameters are:

[0037] 1. Charge multiple cell samples with different and known capacities according to preset cutoff conditions.

[0038] 2. Create a relationship table between cell capacity and battery charging parameters based on the charging process.

[0039] Specifically, a batch of battery cells are processed in advance in a full charge and discharge manner to obtain the actual battery cell capacity of the batch of battery cells, and then a plurality of battery cell samples with different and uniform capacity values ​​are selected therefrom. For example, 20 battery cell samples are selected, with a capacity range from 100Ah to 102Ah, and a difference of 0.1Ah between adjacent samples. Each battery cell sample is then charged according to a preset cutoff condition, and when each battery cell sample reaches the preset cutoff condition, the battery charging parameters corresponding to each battery cell sample are recorded. Then, using the battery cell sample as an index, a relationship table between battery cell capacity and battery charging parameters can be created according to the one-to-one correspondence between battery charging parameters and battery cell capacity.

[0040] In this embodiment, the preset cut-off condition can select a preset time length, and when the battery sample is charged at a constant current to the preset time length, the open circuit voltage of the battery sample is recorded as the battery charging parameter. In addition, the preset cut-off condition can also select a preset voltage value, and when the battery sample is charged at a constant current to the preset voltage value, the currently charged capacity is recorded as the battery charging parameter.

[0041] like Figure 2 As shown, it is the dV / dQ curve of the lithium iron phosphate battery cell (dV / dQ is the voltage change per unit capacity). It is not difficult to find that when the battery cell is charged to a capacity range of 13% to 20% SOC, the open circuit voltage is more sensitive to the capacity change and is easy to be used as a target identification area for predicting capacity. Based on this, in this embodiment, the preset time length is selected between 25 and 35 minutes as the preset cutoff condition, thereby controlling the charge amount to be between 13% and 20% SOC. The preset voltage value is selected between 3.230V and 3.260V, thereby controlling the charge amount to be between 13% and 20% SOC. By determining the above parameters, a relationship table for accurately predicting the capacity of the battery cell can be created.

[0042] The following is a specific example to explain the process of creating a relationship table between battery cell capacity and battery charging parameters:

[0043] Select 20 cell samples with known capacity ranging from 100Ah to 102Ah, with a difference of 0.1Ah between adjacent samples; select a 1 / 3C current ratio to discharge the cell samples to the lowest voltage; charge the battery with a smaller current of 1 / 3C (the purpose of charging with a smaller current is to extend the charging time, and the curve of capacity and voltage is smoother, so that the sampling is more accurate), the charging time is about 30 minutes, and the voltage value of each cell sample after the termination is recorded at 30 minutes. For the above 20 cell samples, the battery is charged with a smaller current of 1 / 3C constant current and constant voltage, and the voltage is cut off at 3.245V, and the charging capacity of each cell sample is recorded. The relationship between the cell capacity and the battery charging parameters is shown in Table 1. Figure 3 and Figure 4They are the relationship diagram between constant voltage charging capacity and battery cell capacity and the relationship diagram between constant current charging voltage and battery cell capacity.

[0044] Table 1. Relationship between the cell capacity and battery charging parameters of a 100Ah lithium iron phosphate cell

[0045]

[0046]

[0047] Therefore, in this embodiment, the current battery cell can be charged at a constant current for 30 minutes and the corresponding open circuit voltage can be recorded, or the current battery cell can be charged at a constant current and constant voltage to 3.245V, and then the corresponding charged capacity can be recorded. By querying the above relationship table based on the recorded parameters, the actual battery capacity value of the current battery cell can be accurately predicted.

[0048] Specifically, in one embodiment, the above step S102 specifically includes the following steps:

[0049] Step 3: Determine the capacity that needs to be charged in the current battery cell based on the product of the actual battery cell capacity of the current battery cell and the preset SOC.

[0050] Step 4: Calculate the difference between the capacity that needs to be charged in the current battery cell and the capacity that has been charged in the current battery cell, and obtain the capacity that has not been charged in the current battery cell.

[0051] Step 5: Based on the ratio of the capacity of the current battery cell that has not yet been charged to the charging current, determine the charging time required for the current battery cell to reach the preset SOC.

[0052] Specifically, in this embodiment, after the actual cell capacity of each cell is predicted during the charging process, the actual cell capacity of the cell is multiplied by the preset SOC to determine how much capacity each cell needs to be charged to achieve SOC alignment. For example, if the current cell is 100Ah and the preset SOC is 50%, then the capacity value that the current cell needs to be charged is 100*50%=50Ah. In the above process of predicting the cell capacity, the cell has only been charged with 13% to 20% of the capacity, which has not yet reached the preset SOC. The capacity that has been charged to the cell is known and can be determined by the product of the charging current and the charging time. Then, the difference between the capacity that the current cell needs to be charged (50Ah in this embodiment) and the capacity that the current cell has been charged is calculated to obtain the capacity that has not yet been charged to the current cell. Then, the ratio of the capacity that has not yet been charged to the charging current is calculated to determine the remaining charging time. The remaining charging time of large-capacity batteries is longer, and the remaining charging time of small-capacity batteries is shorter. Finally, by charging each battery cell according to the calculated remaining charging time, the SOC of each battery cell can be accurately aligned, thereby further improving the consistency of the battery cell voltage while ensuring shipment efficiency.

[0053] Specifically, in one embodiment, a battery cell charging method provided by an embodiment of the present invention further includes the following steps:

[0054] Step 6: Divide each charged battery cell into a plurality of groups based on the actual battery cell capacity of each battery cell, wherein the actual battery cell capacity of the battery cells in the same group all fall within the same preset range.

[0055] Step 7: Select the battery pack from the same group of cells.

[0056] Specifically, in this embodiment, the battery cells after the above-mentioned SOC alignment are grouped again, and multiple battery cells with relatively close actual battery cell capacities are grouped into the same group according to the capacity range. Then, when selecting the battery pack, the battery cells of the same battery pack are selected in the same group to prevent large differences in the battery cell voltages in the same battery pack, thereby further improving the consistency of the battery cell voltages.

[0057] Through the above steps, the technical solution provided by the present application is to ensure the consistency of the voltage of each battery cell when the battery is shipped, so as to determine the target to ensure that the SOC of each battery cell in the package is consistent when the battery is shipped. Therefore, when charging each battery cell, firstly, a plurality of batteries are slowly charged with a constant small current through a preset cutoff condition, so as to accurately predict the actual battery cell capacity of each battery cell. If the SOC of each battery cell is made consistent, it will take a longer charging time for a large-capacity battery cell to charge to the preset SOC, and a shorter charging time for a small-capacity battery cell. Therefore, the remaining charging time for each battery cell to charge to the preset SOC can be accurately calculated based on the actual battery cell capacity of each battery cell and the capacity that has been charged. Then, charging is continued according to the charging time calculated for each battery cell. When the charging time of each battery cell is reached, the shipping SOC of each battery cell can be guaranteed to be consistent, and all are preset SOCs, thereby improving the consistency of the voltage of each battery cell under the premise of ensuring the shipping efficiency.

[0058] like Figure 5 As shown, this embodiment also provides a battery cell charging device, the device comprising:

[0059] The capacity prediction unit 101 is used to charge multiple cells based on a preset cutoff condition and predict the actual cell capacity of each cell according to the charging process. For details, please refer to the relevant description of step S101 in the above method embodiment, which will not be repeated here.

[0060] The time determination unit 102 is used to calculate the charging time required for each battery cell to reach a preset SOC based on the actual battery cell capacity of each battery cell and the capacity of each battery cell that has been charged. The preset SOC is the SOC relative to the actual battery cell capacity of each battery cell. For details, please refer to the relevant description of step S102 in the above method embodiment, which will not be repeated here.

[0061] The post-charging unit 103 is used to charge each battery cell according to the charging time corresponding to each battery cell. For details, please refer to the relevant description of step S103 in the above method embodiment, which will not be repeated here.

[0062] The battery cell charging device provided in the embodiment of the present invention is used to execute the battery cell charging method provided in the above embodiment. Its implementation method and principle are the same. For details, please refer to the relevant description of the above method embodiment, which will not be repeated here.

[0063] Through the cooperation of the above-mentioned components, the technical solution provided by the present application is to ensure the consistency of the voltage of each battery cell when the battery is shipped, so as to determine the target to ensure that the SOC of each battery cell in the package is consistent when the battery is shipped. Therefore, when charging each battery cell, firstly, a plurality of batteries are slowly charged with a constant small current through a preset cutoff condition, so as to accurately predict the actual battery cell capacity of each battery cell. If the SOC of each battery cell is consistent, it will take a longer charging time for a large-capacity battery cell to charge to the preset SOC, and a shorter charging time for a small-capacity battery cell. Therefore, the remaining charging time for each battery cell to charge to the preset SOC can be accurately calculated based on the actual battery cell capacity of each battery cell and the capacity that has been charged. Then, charging continues according to the charging time calculated for each battery cell. When the charging time of each battery cell is reached, the shipping SOC of each battery cell can be guaranteed to be consistent, and all are preset SOCs, thereby improving the consistency of the voltage of each battery cell under the premise of ensuring the shipping efficiency.

[0064] Figure 6 An electronic device according to an embodiment of the present invention is shown, the device includes a processor 901 and a memory 902, which can be connected via a bus or other means. Figure 6 The example of connecting through bus is taken in the following.

[0065] The processor 901 may be a central processing unit (CPU). The processor 901 may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or a combination of the above chips.

[0066] The memory 902 is a non-transitory computer-readable storage medium that can be used to store non-transitory software programs, non-transitory computer executable programs and modules, such as program instructions / modules corresponding to the methods in the above method embodiments. The processor 901 executes various functional applications and data processing of the processor by running the non-transitory software programs, instructions and modules stored in the memory 902, that is, implementing the methods in the above method embodiments.

[0067] The memory 902 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required by at least one function; the data storage area may store data created by the processor 901, etc. In addition, the memory 902 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 902 may optionally include a memory remotely arranged relative to the processor 901, and these remote memories may be connected to the processor 901 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.

[0068] One or more modules are stored in the memory 902 , and when executed by the processor 901 , the method in the above method embodiment is executed.

[0069] The specific details of the above electronic device can be understood by referring to the corresponding descriptions and effects in the above method embodiments, and will not be repeated here.

[0070] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the implemented program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, the storage medium can be a disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), a flash memory, a hard disk drive (HDD) or a solid-state drive (SSD), etc.; the storage medium can also include a combination of the above-mentioned types of memory.

[0071] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery cell charging method, characterized in that: The method comprises: charging a plurality of battery cells based on a preset cutoff condition, and predicting an actual battery cell capacity of each battery cell according to the charging process; The charging time required for each battery cell to reach a preset SOC is calculated based on the actual battery cell capacity of each battery cell and the capacity that has been charged into each battery cell, wherein the preset SOC is the SOC relative to the actual battery cell capacity of each battery cell; the charging time required for each battery cell to reach the preset SOC based on the actual battery cell capacity of each battery cell and the capacity that has been charged into each battery cell comprises: determining the capacity that needs to be charged into the current battery cell based on the product of the actual battery cell capacity of the current battery cell and the preset SOC; calculating the difference between the capacity that needs to be charged into the current battery cell and the capacity that has been charged into the current battery cell to obtain the capacity that has not been charged into the current battery cell; determining the charging time required for the current battery cell to reach the preset SOC based on the ratio of the capacity that has not been charged into the current battery cell to the charging current; Charging each battery cell according to the charging time corresponding to each battery cell; The method of charging a plurality of battery cells based on a preset cutoff condition and predicting the actual battery cell capacity of each battery cell according to the charging process includes: charging a current battery cell, and when the current battery cell reaches the preset cutoff condition, recording a current battery charging parameter corresponding to the current battery cell; and determining the actual battery cell capacity of the current battery cell from a relationship table between battery cell capacity and battery charging parameter based on the current battery charging parameter; The relationship table between the cell capacity and the battery charging parameters is obtained by: charging a plurality of cell samples with different capacities and known capacities according to the preset cutoff condition; and creating the relationship table between the cell capacity and the battery charging parameters according to the charging process; The method also includes: dividing each charged battery cell into multiple groups based on the actual battery cell capacity of each battery cell, wherein the actual battery cell capacity of the battery cells in the same group all fall within the same preset range; and selecting a battery pack from the same group of battery cells.

2. The method according to claim 1, characterized in that The preset cut-off condition is a preset time length, and the relationship table between the cell capacity and the battery charging parameters is created according to the charging process, including: When the charging time of each of the battery cell samples reaches the preset time length, recording the current open circuit voltage corresponding to each of the battery cell samples, and using the open circuit voltage as the battery charging parameter; A relationship table between the cell capacity and the corresponding open circuit voltage of each cell sample is created as a relationship table between the cell capacity and the battery charging parameters.

3. The method according to claim 1, characterized in that The preset cut-off condition is a preset voltage value, and the relationship table between the cell capacity and the battery charging parameters is created according to the charging process, including: When the charging voltage of each battery cell sample reaches the preset voltage value, the charged capacity corresponding to each battery cell sample is recorded, and the charged capacity is used as the battery charging parameter; A relationship table between the cell capacity and the corresponding charged capacity of each cell sample is created as a relationship table between the cell capacity and the battery charging parameters.

4. A battery cell charging device, characterized in that: The device comprises: A capacity prediction unit, used for charging a plurality of battery cells based on a preset cutoff condition, and predicting the actual battery cell capacity of each battery cell according to the charging process; the charging of a plurality of battery cells based on the preset cutoff condition, and predicting the actual battery cell capacity of each battery cell according to the charging process, comprises: charging a current battery cell, and when the current battery cell reaches the preset cutoff condition, recording a current battery charging parameter corresponding to the current battery cell; determining the actual battery cell capacity of the current battery cell from a relationship table of battery cell capacity and battery charging parameters based on the current battery charging parameters; the relationship table of battery cell capacity and battery charging parameters is obtained in the following manner: charging a plurality of battery cell samples with different capacities and known capacities according to the preset cutoff condition; and creating a relationship table of battery cell capacity and battery charging parameters according to the charging process; A time determination unit, used for calculating the charging time required for each battery cell to reach a preset SOC based on the actual battery cell capacity of each battery cell and the capacity that has been charged into each battery cell, wherein the preset SOC is the SOC relative to the actual battery cell capacity of each battery cell; the calculation of the charging time required for each battery cell to reach the preset SOC based on the actual battery cell capacity of each battery cell and the capacity that has been charged into each battery cell comprises: determining the capacity that needs to be charged into the current battery cell based on the product of the actual battery cell capacity of the current battery cell and the preset SOC; calculating the difference between the capacity that needs to be charged into the current battery cell and the capacity that has been charged into the current battery cell to obtain the capacity that has not been charged into the current battery cell; determining the charging time required for the current battery cell to reach the preset SOC based on the ratio of the capacity that has not been charged into the current battery cell to the charging current; The post-charging unit is used to charge each battery cell according to the charging time corresponding to each battery cell; divide each charged battery cell into multiple groups based on the actual battery cell capacity of each battery cell, wherein the actual battery cell capacity of the same group falls within the same preset range; and select the battery pack from the same group of batteries.

5. An electronic device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method according to any one of claims 1 to 3 by executing the computer instructions.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the method according to any one of claims 1 to 3.

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