Battery equalization processing method and apparatus, and electronic device and storage medium

Abstract

A battery equalization processing method and apparatus, and an electronic device and a storage medium. The method comprises: determining a full-discharge capacity difference between each battery cell and the battery cell having the lowest full-discharge capacity in a fully discharged state; determining a full-charge capacity difference between each battery cell and the battery cell having the highest full-charge capacity in a fully charged state; determining the total capacity of each battery cell from the fully discharged state to the fully charged state; determining the current total capacity of each battery cell in the fully charged state; and on the basis of the total capacity of each battery cell, the current total capacity of each battery cell, and each full-charge capacity difference, determining an equalization amount of each battery cell, and on the basis of the equalization amount of each battery cell, performing charge / discharge equalization on each battery cell. By means of an association relationship between voltage characteristics and capacity, full-discharge capacity differences and full-charge capacity differences that are determined are more reasonable, such that a determined equalization amount of each battery cell is more accurate, thereby achieving a better equalization effect for each battery cell.

Description

Battery equalization processing methods, devices, electronic equipment and storage media

[0001] Cross-references to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 2024115186308, filed on October 28, 2024, entitled "Battery Equalization Processing Method, Apparatus, Electronic Device and Storage Medium", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of battery technology, and more specifically, to a battery equalization processing method, apparatus, electronic device, and storage medium. Background Technology

[0004] For large-scale energy storage systems, such as electric vehicles and energy storage boxes, multiple battery cells need to be connected in series. Due to differences in manufacturing processes, assembly technologies, and aging paths, the capacity, voltage, and internal resistance of the cells will gradually increase with aging. If not addressed in time, this will lead to a significant reduction in the usable capacity of the battery pack and shorten its lifespan. To fully utilize the charge and discharge performance of the battery pack and slow down its lifespan degradation, it is necessary to dynamically adjust the remaining capacity of each battery cell.

[0005] In existing technologies, commonly used equalization schemes include capacity equalization and voltage equalization. Capacity equalization mainly identifies the cell with the lowest capacity and calculates the capacity difference between the other cells and the cell with the lowest capacity. Equalization discharge stops when the capacity difference is less than a certain threshold. Voltage equalization mainly identifies the cell with the lowest voltage difference and calculates the voltage difference between the other cells and the cell with the lowest voltage difference. Equalization discharge stops when the voltage difference is less than a certain threshold. Both methods have unreasonable calculations of the equalization amount and unreasonable equalization stopping conditions, resulting in poor battery equalization performance and consequently, short battery life. Summary of the Invention

[0006] The purpose of this disclosure is to address the shortcomings of the prior art by providing a battery equalization processing method, apparatus, electronic device, and storage medium to improve the accuracy of battery equalization processing.

[0007] To address the aforementioned technical problems, in a first aspect, this disclosure provides a battery balancing method for performing charge-discharge balancing on individual cells in a battery pack, the method comprising:

[0008] Based on the target discharge voltage of each individual cell in the venting state, the first mapping relationship between voltage and capacity during the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the venting state and the final total discharge capacity during the discharge process, the discharge capacity difference between each individual cell and the individual cell with the lowest discharge capacity in the venting state is determined; wherein, the target discharge voltage is obtained by correcting the actual discharge voltage of the individual cell in the venting state, and the individual cell with the lowest discharge capacity is the individual cell with the lowest actual discharge voltage in the venting state.

[0009] Based on the target charging voltage of each individual cell when fully charged, the second mapping relationship between voltage and capacity during the charging process, and the difference in charging capacity between the total charging capacity of the battery pack when fully charged and the final total charging capacity during the charging process, the full-charge capacity difference between each individual cell and the cell with the highest full charge when fully charged is determined; wherein, the target charging voltage is obtained by correcting the actual charging voltage of the individual cell when fully charged, and the cell with the highest full charge is the individual cell with the highest actual charging voltage when fully charged;

[0010] The total capacity of each individual cell from the vented state to the fully charged state is determined based on the vented capacity difference, the fully charged capacity difference, and the total capacity of the battery pack.

[0011] Based on the difference in venting capacity of each individual cell and the total capacity of the battery pack, determine the current total capacity of each individual cell when fully charged.

[0012] Based on the total capacity of each individual battery cell, the current total capacity of each individual battery cell, and the difference in fully charged capacity of each individual battery cell, the equalization amount of each individual battery cell is determined, and the charge and discharge equalization of each individual battery cell is performed based on the equalization amount of each individual battery cell.

[0013] In one optional implementation, determining the discharge capacity difference between each individual cell and the cell with the lowest discharge capacity in the discharged state, based on the target discharge voltage of each individual cell in the discharged state, the first mapping relationship between voltage and capacity during the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the discharged state and the final total discharge capacity during the discharge process, includes:

[0014] Determine the actual discharge voltage before correction to the target discharge voltage based on the target discharge voltage;

[0015] Based on the first mapping relationship between voltage and capacity during the discharge process, the discharge capacity corresponding to the actual discharge voltage is determined, and the discharge capacity is used as the first target capacity corresponding to the target discharge voltage.

[0016] The sum of the difference between the first target capacity and the discharge capacity is taken as the venting capacity difference;

[0017] In one optional implementation, determining the difference in charging capacity between each individual cell and the highest-charged cell when fully charged, based on the target charging voltage of each individual cell when fully charged, the second mapping relationship between voltage and capacity during the charging process, and the difference in charging capacity between the total charging capacity of the battery pack when fully charged and the final total charging capacity during the charging process, includes:

[0018] Determine the actual charging voltage before correction to the target charging voltage based on the target charging voltage;

[0019] Based on the second mapping relationship between voltage and capacity during the charging process, the charging capacity corresponding to the actual charging voltage is determined, and the charging capacity is used as the second target capacity corresponding to the target charging voltage.

[0020] The sum of the difference between the second target capacity and the charging capacity is taken as the full charge capacity difference.

[0021] In one optional implementation, the first mapping relationship between voltage and capacity during the discharge process is determined through the following steps:

[0022] During the discharge process of the battery pack, the first total discharge capacity of the battery pack and its corresponding first minimum single cell voltage are obtained at preset capacity change intervals. When the battery pack is in a discharged state, the total discharge capacity of the battery pack and its corresponding minimum single cell voltage are obtained.

[0023] Based on each first total discharge capacity and its corresponding first minimum single cell voltage, and the total discharge capacity and its corresponding minimum single cell voltage, determine the first mapping relationship between the voltage and capacity during the discharge process;

[0024] In one optional implementation, the second mapping relationship between voltage and capacity during the charging process is determined through the following steps:

[0025] During the charging process of the battery pack, the second total charging capacity of the battery pack and its corresponding second highest single cell voltage are obtained at preset capacity change intervals; when the battery pack is fully charged, the total charging capacity of the battery pack and its corresponding highest single cell voltage are obtained.

[0026] Based on each second total charging capacity and its corresponding second highest single cell voltage, and the total charging capacity and its corresponding highest single cell voltage, a second mapping relationship between voltage and capacity is determined during the charging process.

[0027] In one optional implementation, the target discharge voltage is obtained by correcting the actual discharge voltage of the single cell in the vented state, including:

[0028] Determine the actual discharge voltage of the single cell when it is in a discharged state, the first voltage change of the single cell under preset conditions, and the second voltage change of the single cell with the lowest discharge.

[0029] Calculate the difference between the first voltage change and the second voltage change;

[0030] The difference between the actual single-cell voltage of the single cell and the difference between the first voltage change is taken as the target discharge voltage of the single cell.

[0031] In one optional implementation, the target charging voltage is obtained by correcting the actual charging voltage of the single cell when it is fully charged, including:

[0032] The actual charging voltage of the single cell when it is fully charged, the third voltage change of the single cell under preset conditions, and the fourth voltage change of the single cell with the highest charge are determined.

[0033] Calculate the difference between the third voltage change and the fourth voltage change;

[0034] The sum of the difference between the actual single-cell voltage and the second voltage change is taken as the target charging voltage of the single-cell battery.

[0035] Optionally, the final total discharge capacity during the discharge process is the last first total discharge capacity of the battery pack obtained by the preset capacity change at the interval.

[0036] The final total charging capacity during the charging process is the last second total charging capacity of the battery pack obtained by the preset capacity change amount at the interval.

[0037] Optionally, the total capacity of each individual battery is the sum of the total capacity of the battery pack, the difference in fully charged capacity of each individual battery, and the difference in discharged capacity of each individual battery.

[0038] The current total capacity of each individual battery cell is the sum of the differences between the total capacity of the battery pack and the discharge capacity of each individual battery cell.

[0039] Optionally, determining the balancing amount of each individual battery based on the total capacity of each individual battery, the current total capacity of each individual battery, and the difference in fully charged capacity of each individual battery includes:

[0040] Determine the minimum total capacity from the total capacity of each of the individual cells and determine the minimum current total capacity from the current total capacity of each of the individual cells;

[0041] Calculate the capacity difference between the minimum total capacity and the minimum current total capacity;

[0042] The difference between the capacity difference and the full-charge capacity difference corresponding to the individual cell is used as the equalization amount of the individual cell.

[0043] Secondly, embodiments of this disclosure also provide a battery equalization processing device, the device comprising:

[0044] The discharge determination module is configured to determine the discharge capacity difference between each individual cell and the cell with the lowest discharge capacity in the discharge state, based on the target discharge voltage of each individual cell in the discharge state, the first mapping relationship between voltage and capacity during the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the discharge state and the final total discharge capacity during the discharge process; wherein, the target discharge voltage is obtained by correcting the actual discharge voltage of the individual cell in the discharge state, and the cell with the lowest discharge capacity is the individual cell with the lowest actual discharge voltage in the discharge state;

[0045] The charging determination module is configured to determine the full-capacity difference between each individual cell and the highest-charged individual cell when fully charged, based on the target charging voltage of each individual cell when fully charged, the second mapping relationship between voltage and capacity during the charging process, and the charging capacity difference between the total charging capacity of the battery pack when fully charged and the final total charging capacity during the charging process; wherein, the target charging voltage is obtained by correcting the actual charging voltage of the individual cell when fully charged, and the highest-charged individual cell is the individual cell with the highest actual charging voltage when fully charged;

[0046] The capacity determination module is configured to determine the total capacity of each individual cell from the vented state to the fully charged state based on the vented capacity difference, the fully charged capacity difference, and the total capacity of the battery pack, and to determine the current total capacity of each individual cell in the fully charged state based on the vented capacity difference and the total capacity of the battery pack.

[0047] The balancing module is configured to determine the balancing amount of each individual battery based on the total capacity of each individual battery, the current total capacity of each individual battery, and the difference in the fully charged capacity of each individual battery, and to perform charge-discharge balancing on each individual battery based on the balancing amount of each individual battery.

[0048] Optionally, the discharge determination module is specifically configured as follows:

[0049] Determine the actual discharge voltage before correction to the target discharge voltage based on the target discharge voltage;

[0050] Based on the first mapping relationship between voltage and capacity during the discharge process, the discharge capacity corresponding to the actual discharge voltage is determined, and the discharge capacity is used as the first target capacity corresponding to the target discharge voltage.

[0051] The sum of the difference between the first target capacity and the discharge capacity is taken as the venting capacity difference;

[0052] Optionally, the charging determination module is specifically configured as follows:

[0053] Determine the actual charging voltage before correction to the target charging voltage based on the target charging voltage;

[0054] Based on the second mapping relationship between voltage and capacity during the charging process, the charging capacity corresponding to the actual charging voltage is determined, and the charging capacity is used as the second target capacity corresponding to the target charging voltage.

[0055] The sum of the difference between the second target capacity and the charging capacity is taken as the full charge capacity difference.

[0056] Optionally, the discharge determination module is specifically configured as follows:

[0057] During the discharge process of the battery pack, the first total discharge capacity of the battery pack and its corresponding first minimum single cell voltage are obtained at preset capacity change intervals. When the battery pack is in a discharged state, the total discharge capacity of the battery pack and its corresponding minimum single cell voltage are obtained.

[0058] Based on each first total discharge capacity and its corresponding first minimum single cell voltage, and the total discharge capacity and its corresponding minimum single cell voltage, determine the first mapping relationship between the voltage and capacity during the discharge process;

[0059] Optionally, the charging determination module is specifically configured as follows:

[0060] During the charging process of the battery pack, the second total charging capacity of the battery pack and its corresponding second highest single cell voltage are obtained at preset capacity change intervals; when the battery pack is fully charged, the total charging capacity of the battery pack and its corresponding highest single cell voltage are obtained.

[0061] Based on each second total charging capacity and its corresponding second highest single cell voltage, and the total charging capacity and its corresponding highest single cell voltage, a second mapping relationship between voltage and capacity is determined during the charging process.

[0062] Optionally, the discharge determination module is specifically configured as follows:

[0063] In the venting state, the actual discharge voltage of the individual cell, the first voltage change of the individual cell under preset conditions, and the second voltage change of the individual cell with the lowest venting value are determined.

[0064] Calculate the difference between the first voltage change and the second voltage change;

[0065] The difference between the actual single-cell voltage of the single cell and the difference between the first voltage change is taken as the target discharge voltage of the single cell.

[0066] Optionally, the charging determination module is specifically configured as follows:

[0067] When fully charged, the actual charging voltage of the individual battery, the third voltage change of the individual battery under preset conditions, and the fourth voltage change of the individual battery with the highest charge are determined.

[0068] Calculate the difference between the third voltage change and the fourth voltage change;

[0069] The sum of the difference between the actual single-cell voltage and the second voltage change is taken as the target charging voltage of the single-cell battery.

[0070] Optionally, the final total discharge capacity during the discharge process is the last first total discharge capacity of the battery pack obtained by the preset capacity change at the interval.

[0071] The final total charging capacity during the charging process is the last second total charging capacity of the battery pack obtained by the preset capacity change amount at the interval.

[0072] Optionally, the total capacity of each individual battery is the sum of the total capacity of the battery pack, the difference in fully charged capacity of each individual battery, and the difference in discharged capacity of each individual battery.

[0073] The current total capacity of each individual battery cell is the sum of the differences between the total capacity of the battery pack and the discharge capacity of each individual battery cell.

[0074] Optionally, the equalization module is specifically configured as follows:

[0075] Determine the minimum total capacity from the total capacity of each of the individual cells and determine the minimum current total capacity from the current total capacity of each of the individual cells;

[0076] Calculate the capacity difference between the minimum total capacity and the minimum current total capacity;

[0077] The difference between the capacity difference and the full-charge capacity difference corresponding to the individual cell is used as the equalization amount of the individual cell.

[0078] Thirdly, embodiments of this disclosure also provide an electronic device, including: a processor, a storage medium, and a bus, wherein the storage medium stores program instructions executable by the processor, and when an application program runs, the processor communicates with the storage medium via the bus, and the processor executes the program instructions to perform the steps of the battery balancing processing method described in the first aspect.

[0079] Fourthly, embodiments of this disclosure also provide a computer-readable storage medium storing a computer program, which is read and executes the steps of the battery equalization processing method described in the first aspect.

[0080] The beneficial effects of this disclosure are:

[0081] This disclosure provides a battery equalization processing method, apparatus, electronic device, and storage medium. When determining the discharge capacity difference between each individual cell and the lowest discharged cell in the discharged state, the method considers the target discharge voltage of each individual cell in the discharged state, the mapping relationship between voltage and capacity during the discharge process, and the difference in the total discharge capacity of the battery pack in the discharged state. This process takes into account the correlation between voltage characteristics and capacity during the battery discharge process, resulting in more reasonable discharge capacity differences. Similarly, when determining the full-charge capacity difference between each individual cell and the highest-charged cell in the fully charged state, the method also considers the correlation between voltage characteristics and capacity during the charging process, resulting in more reasonable full-charge capacity differences. Reasonable; when determining the total capacity of each individual cell from the discharged state to the fully charged state, the differences in total capacity between individual cells when fully charged and the differences in total capacity between individual cells when discharged are taken into account, which makes the obtained total capacity of individual cells more reasonable; when determining the current total capacity of each individual cell when fully charged, the difference in discharge capacity between each individual cell when discharged and the individual cell with the lowest discharge capacity is taken into account, which makes the obtained current total capacity of individual cells more reasonable; therefore, balancing based on the additional discharge capacity of each individual cell obtained from the aforementioned total capacity of each individual cell, the current total capacity of each individual cell, and the difference in full charge capacity can result in a better balancing effect and improve the service life of the battery pack. Attached Figure Description

[0082] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0083] Figure 1 is a schematic flowchart of a battery equalization processing method provided in an embodiment of this disclosure;

[0084] Figure 2 is a schematic flowchart of a method for determining a mapping relationship according to an embodiment of this disclosure;

[0085] Figure 3 is a schematic diagram of another process for determining mapping relationships provided in an embodiment of this disclosure;

[0086] Figure 4 is a schematic flowchart of a method for determining a target discharge voltage according to an embodiment of this disclosure;

[0087] Figure 5 is a schematic diagram of a process for determining a target charging voltage according to an embodiment of this disclosure;

[0088] Figure 6 is a schematic flowchart of another battery equalization processing method provided in an embodiment of this disclosure;

[0089] Figure 7 is a battery balancing effect diagram provided in an embodiment of this disclosure;

[0090] Figure 8 is a schematic diagram of an apparatus for a battery equalization processing method provided in an embodiment of this disclosure;

[0091] Figure 9 is a structural block diagram of an electronic device provided in an embodiment of this disclosure. Detailed Implementation

[0092] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the accompanying drawings in this disclosure are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this disclosure. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this disclosure illustrate operations implemented according to some embodiments of this disclosure. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this disclosure, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0093] Furthermore, the described embodiments are merely some, not all, of the embodiments of this disclosure. The components of the embodiments of this disclosure typically described and illustrated in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this disclosure provided in the drawings is not intended to limit the scope of the claimed disclosure, but merely to illustrate selected embodiments of the disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0094] It should be noted that the term "comprising" will be used in the embodiments of this disclosure to indicate the presence of the features subsequently declared, but does not exclude the addition of other features.

[0095] For battery packs, common balancing methods include capacity balancing and voltage balancing.

[0096] Voltage equalization typically occurs after charging is complete by comparing the voltage difference between each individual cell in the battery pack and the lowest voltage individual cell. If the voltage difference between a single cell and the lowest voltage individual cell is greater than a certain threshold, the cell corresponding to that voltage is discharged. If the voltage difference is less than a certain threshold, equalization stops. This method can only be used in the static state after charging is complete. Because it only considers the voltage difference after charging and ignores the inconsistency in capacity between individual cells, it can lead to erroneous equalization operations. This is because the highest voltage individual cell after charging may also be the lowest voltage individual cell at the end of discharge. At this point, the battery pack capacity has reached its maximum; equalizing the highest voltage individual cell at this stage would only have the opposite effect.

[0097] Capacity balancing typically involves identifying the capacity differences between individual cells and balancing them by comparing the capacity of each individual cell with the lowest-capacity cell. Balancing is activated if the difference between a cell's capacity and the lowest-capacity cell's capacity exceeds 1% of its state of charge (SOC); otherwise, it is deactivated. This method generally assumes that the total capacity of each individual cell is consistent, neglecting the differences in capacity when cells are fully charged. This can lead to many unintended balancing issues. Furthermore, the cell with the lowest capacity is not necessarily the cell with the lowest voltage. When a cell has a high initial SOC, it also needs to be equalized by discharge.

[0098] Based on the foregoing description of the prior art, it can be seen that the calculation of the equilibrium quantity in the two methods of the prior art is unreasonable and the equilibrium stopping condition is also unreasonable.

[0099] Therefore, this disclosure proposes a battery balancing method that balances the battery based on its voltage characteristics and capacity statistics when it is fully charged and discharged, which can ensure the high efficiency of balancing and effectively improve the service life of the battery pack.

[0100] Optionally, the battery balancing processing method provided in this disclosure can be applied to an electronic device, such as a mobile phone, tablet computer, laptop computer, PDA, desktop computer, or other terminal device with computing power and display function, or it can be a server. Specifically, it can be applied to applications in the terminal device, such as mobile phone apps (APPs) or computer application systems. When the executing entity is a server, it can communicate wirelessly with a measuring device measuring the charging and discharging process of the battery pack to obtain the data of the battery pack during the charging and discharging process measured by the measuring device. Then, using the battery balancing processing method provided in this disclosure, the additional discharge capacity of each individual battery cell can be obtained, thereby balancing the charging and discharging of each individual battery cell.

[0101] The following is a detailed explanation of the specific implementation process of the battery equalization processing provided in the embodiments of this disclosure.

[0102] Figure 1 is a schematic flowchart of a battery equalization processing method provided in an embodiment of this disclosure. The execution subject of this method is the aforementioned electronic device, used to perform charge-discharge equalization on each individual cell in the battery pack. As shown in Figure 1, the method includes:

[0103] S101. Based on the target discharge voltage of each individual cell in the venting state, the first mapping relationship between voltage and capacity during the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the venting state and the final total discharge capacity during the discharge process, determine the discharge capacity difference between each individual cell and the individual cell with the lowest discharge capacity in the venting state.

[0104] The battery pack contains at least one individual cell, which is connected in series. The target discharge voltage is obtained by correcting the actual discharge voltage of the individual cell in a fully discharged state. The actual discharge voltage is measured when the individual cell is in a fully discharged state. The target discharge voltage can be represented by Array1_〖CellV〗^', and the actual discharge voltage can be represented by Array1_CellV. The lowest discharged individual cell refers to the individual cell with the lowest actual discharge voltage in a fully discharged state.

[0105] Optionally, the first mapping relationship between voltage and capacity during the discharge process can be obtained by using a preset method based on the actual discharge voltage of each individual cell and the discharge capacity of the battery pack during the discharge process. When determining the discharge capacity difference between each individual cell in the vented state and the cell with the lowest discharge capacity, not only the target discharge voltage of each individual cell in the vented state is considered, but also the characteristic relationship between voltage and capacity during the discharge process. Compared with the prior art, which only considers the voltage difference or capacity difference at the end of discharge, the determined discharge capacity difference in the vented state is more reasonable.

[0106] The total discharge capacity of the battery pack in the vented state is represented by Cap1_dch, and the final total discharge capacity during the discharge process is represented by Cap1_dch_latest. Therefore, the discharge capacity difference dCap1_dch between the total discharge capacity in the vented state and the final total discharge capacity during the discharge process is the difference between Cap1_dch and Cap1_dch_latest. The final total discharge capacity during the vented state refers to the total capacity of the battery pack when the preset capacity change amount described below is triggered for the last time during the discharge process. This is because the change in the total discharge capacity of the battery pack in the vented state and the final total discharge capacity may not be the preset capacity change amount mentioned above. For example, the difference between Cap1_dch and Cap1_dch_latest may not be 0.1Ah.

[0107] S102. Based on the target charging voltage of each individual cell when fully charged, the second mapping relationship between voltage and capacity during the charging process, and the difference in charging capacity between the total charging capacity of the battery pack when fully charged and the final total charging capacity during the charging process, determine the difference in full-charge capacity between each individual cell and the cell with the highest full charge when fully charged.

[0108] Here, "highest fully charged single cell" refers to the single cell with the highest actual charging voltage when fully charged. "Target charging voltage" is obtained by correcting the actual charging voltage of this single cell when fully charged; the actual charging voltage is obtained by measuring the voltage of this single cell when fully charged. The target charging voltage can be represented by 〖Array2_CellV〗^', and the actual charging voltage can be represented by Array2_CellV.

[0109] Optionally, the second mapping relationship between voltage and capacity during the charging process can be obtained using a preset method from the actual charging voltage of each individual cell in the battery pack and the charging capacity of the battery pack during the charging process. When determining the difference in full-charge capacity between each individual cell and the highest-charged individual cell, not only the target charging voltage of each individual cell at full charge is considered, but also the characteristic relationship between voltage and capacity during the charging process. Compared with the prior art, which only considers the voltage difference or capacity difference at the end of full charge, the determined full-charge capacity differences at full charge are more reasonable.

[0110] The total charging capacity of the battery pack when fully charged is represented by Cap2_dch, and the final total charging capacity during the charging process is represented by Cap2_dch_latest. The difference between the total charging capacity when fully charged and the final total charging capacity during the charging process is the difference between Cap2_dch and Cap2_dch_latest. Therefore, the charging capacity difference dCap2_dch = Cap2_dch - Cap2_dch_latest. The final total charging capacity during the charging process refers to the total capacity of the battery pack when the preset capacity change amount described below is triggered for the last time during the charging process.

[0111] S103. Determine the total capacity of each individual cell from the vented state to the fully charged state based on the differences in vented capacity, the differences in fully charged capacity, and the total capacity of the battery pack.

[0112] The total capacity of the battery pack refers to the cumulative total capacity of the battery pack from the discharged state to the fully charged state, which can be represented by Q0, for example.

[0113] Specifically, the total capacity of each individual cell from the discharged state to the fully charged state can be determined using a preset method based on the discharge capacity difference between each individual cell and the lowest discharged individual cell, the full charge capacity difference between each individual cell and the highest fully charged individual cell, and the total capacity of the battery pack. The total capacity of each individual cell can be represented, for example, by Array_Q.

[0114] Optionally, it can be seen that when determining the total capacity of each individual cell from the vented state to the fully charged state, both the vented capacity difference between each individual cell and the lowest vented individual cell in the vented state and the fully charged capacity difference between each individual cell and the highest fully charged individual cell in the fully charged state are taken into account. This takes into account the differences in the total capacity between each individual cell when fully charged and the differences in the total capacity between each individual cell when vented, which can make the obtained total capacity of each individual cell more reasonable and avoid the situation in the prior art where the total capacity of each individual cell is regarded as the same, resulting in an unintended balance.

[0115] S104. Determine the current total capacity of each individual cell when it is fully charged, based on the difference in venting capacity and the total capacity of the battery pack.

[0116] Optionally, the current total capacity of each individual cell when fully charged can be determined based on the difference in discharge capacity between each individual cell and the lowest discharged individual cell, as well as the total capacity of the battery pack. The current total capacity of each individual cell can be represented, for example, by Array_QP, and can be obtained specifically through the following formula (vi).

[0117] Optionally, when determining the current total capacity of each individual cell in the fully charged state, the difference in discharge capacity between each individual cell in the discharged state and the cell with the lowest discharge capacity is taken into account, which can make the current total capacity of each individual cell more reasonable.

[0118] S105. Based on the total capacity of each individual cell, the current total capacity of each individual cell, and the difference in fully charged capacity, determine the equalization amount of each individual cell, and perform charge-discharge equalization on each individual cell based on the equalization amount of each individual cell.

[0119] The total capacity of a single cell refers to the total capacity of that single cell from a discharged state to a fully charged state, while the current total capacity of a single cell refers to the total capacity of that single cell when the battery pack is fully charged.

[0120] Specifically, the equalization amount of each individual cell can be determined using a preset method based on the total capacity of each individual cell from the vented state to the fully charged state, the current total capacity of each individual cell when the battery pack is fully charged, and the difference in fully charged capacity between each individual cell and the cell with the highest full charge.

[0121] In this embodiment, when determining the discharge capacity difference between each individual battery and the lowest discharged individual battery in the discharged state, it is based on the target discharge voltage of each individual battery in the discharged state, the first mapping relationship between voltage and capacity during discharge, and the discharge capacity difference between the total discharge capacity of the battery pack in the discharged state and the final total discharge capacity during discharge. This process takes into account the correlation between voltage characteristics and capacity during battery discharge, making the obtained discharge capacity differences more reasonable. Similarly, when determining the full charge capacity difference between each individual battery and the highest fully charged individual battery in the fully charged state, the correlation between voltage characteristics and capacity during charging is considered, making the obtained full charge capacity differences more reasonable. Reasonable; when determining the total capacity of each individual cell from the discharged state to the fully charged state, the differences in total capacity between individual cells when fully charged and the differences in total capacity between individual cells when discharged are taken into account, making the obtained total capacity of each individual cell more reasonable; when determining the current total capacity of each individual cell when fully charged, the difference in discharge capacity between each individual cell when discharged and the individual cell with the lowest discharge capacity is taken into account, making the obtained current total capacity of each individual cell more reasonable; therefore, balancing based on the balance amount of each individual cell obtained from the aforementioned total capacity of each individual cell, the current total capacity of each individual cell, and the difference in fully charged capacity can result in a better balancing effect and improve the service life of the battery pack.

[0122] Optionally, in S101 above, determining the discharge capacity difference between each individual cell and the cell with the lowest discharge capacity in the discharge state, based on the target discharge voltage of each individual cell in the discharge state, the first mapping relationship between voltage and capacity during the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the discharge state and the final total discharge capacity during the discharge process, may include:

[0123] Optionally, the actual discharge voltage before correction to the target discharge voltage can be determined based on the target discharge voltage. Then, based on the first mapping relationship between voltage and capacity during the discharge process, the discharge capacity corresponding to the actual discharge voltage can be determined, and this discharge capacity can be used as the first target capacity corresponding to the target discharge voltage. The sum of the difference between the first target capacity and the discharge capacity is used as the discharge capacity difference Array1_dvmin_Cap between the single cell and the single cell with the lowest discharge capacity. The discharge capacity difference can be represented by dCap1_dch. Specifically, the discharge capacity difference can be obtained by the following formula (I).

[0124] Optionally, in S102 above, determining the difference in charging capacity between each individual cell and the highest-charged cell in the fully charged state, based on the target charging voltage of each individual cell when fully charged, the second mapping relationship between voltage and capacity during the charging process, and the difference in charging capacity between the total charging capacity of the battery pack when fully charged and the final total charging capacity during the charging process, may include:

[0125] Optionally, the actual charging voltage before correction to the target charging voltage can be determined based on the target charging voltage. Then, based on the second mapping relationship between voltage and capacity during the charging process, the charging capacity corresponding to the actual charging voltage can be determined, and the charging capacity can be used as the second target capacity corresponding to the target charging voltage. The sum of the difference between the second target capacity and the charging capacity, dCap2_dch, can be used as the full-charge capacity difference, Array2_dVmax_Cap. The full-charge capacity difference can be obtained specifically through the following formula (II).

[0126] Figure 2 is a flowchart illustrating the determination of a mapping relationship according to an embodiment of this disclosure. As shown in Figure 2, the first mapping relationship between voltage and capacity during the discharge process can be determined through the following steps:

[0127] S201. During the discharge process of the battery pack, the first total discharge capacity of each battery pack and its corresponding first minimum single cell voltage are obtained at preset capacity change intervals. When the battery pack is in a venting state, the total discharge capacity of the battery pack and its corresponding minimum single cell voltage are obtained.

[0128] For example, the preset capacity change can be 0.1 Ah. That is, when the total discharge capacity of the battery pack changes by 0.1 Ah, the first total discharge capacity after the 0.1 Ah change and the first lowest single-cell voltage corresponding to the first total discharge capacity are obtained. Specifically, if the battery pack contains 5 single cells, such as single cell A, single cell B, single cell C, and single cell D, and if the first total discharge capacity of the battery pack changes from 9 Ah to 8.9 Ah, and the single-cell voltage of single cell A is the lowest among these 5 single cells, then the single-cell voltage of single cell A is taken as the first lowest single-cell voltage corresponding to 8.9 Ah. At the same time, the total discharge capacity corresponding to the last lowest single-cell voltage can also be obtained, for example, it can be represented by Cap1_dch_latest. The total discharge capacity corresponding to the last first lowest single-cell voltage is also the last total discharge capacity in the discharge process in S101 mentioned above.

[0129] Optionally, when the battery pack is in a discharged state, the total discharge capacity of the battery pack and its corresponding lowest single cell voltage are obtained.

[0130] S202. Based on the first total discharge capacity and its corresponding first minimum single cell voltage, and the total discharge capacity and its corresponding minimum single cell voltage, determine the first mapping relationship between voltage and capacity during the discharge process.

[0131] For example, a 20-dimensional array Array1_minV can be set up. During discharge, the first total discharge capacity of the battery pack and the first lowest single-cell voltage corresponding to the first total discharge capacity can be obtained every preset capacity change. Each time the condition of the preset capacity change of the battery pack's total discharge capacity is triggered, the array is shifted one position to the right, and the new first lowest single-cell voltage is filled into the first element of the array, until the data at the 20th position is replaced by the data at the 19th position. The first total discharge capacity at the last time the condition of the preset capacity change of the total discharge capacity is triggered is recorded as Cap1_dch_latest.

[0132] Optionally, the first total discharge capacity and the total discharge capacity of the battery pack in the venting state can be used as the vertical axis, and the first minimum single cell voltage corresponding to each first total discharge capacity and the minimum single cell voltage in the venting state can be used as the horizontal axis. Then, the first mapping relationship between voltage and capacity during the discharge process can be obtained.

[0133] In this embodiment, the correlation between voltage characteristics and capacity can be obtained based on the first mapping relationship between voltage and capacity during the discharge process.

[0134] Optionally, after determining the first mapping relationship between voltage and capacity during the discharge process, the difference in discharge capacity between each individual cell and the individual cell with the lowest discharge capacity can also be obtained by the following formula (I).

[0135] Specifically, the array Array1_minV can be used as the horizontal axis, and the index number corresponding to the voltage of each first lowest single cell in the array, Index_Array_minV = [0,1,2,3…19], can be used as the vertical axis. The discharge capacity difference Array1_dVmin_Cap between each single cell and the lowest discharged single cell can be obtained by formula (I).

[0136] Array1_dVmin_Cap=0.1×LookUpTable(Array1_minV, Index_Array_minV, Array1_CellV^')+dCap1_dch formula (1)

[0137] The LookUpTable function uses linear interpolation to calculate the venting capacity difference. If the value exceeds the boundary value, the boundary value is used.

[0138] Figure 3 is a schematic flowchart of another method for determining the mapping relationship provided in an embodiment of this disclosure. As shown in Figure 3, the second mapping relationship between voltage and capacity during the charging process can be determined through the following steps:

[0139] S301. During the battery pack charging process, the second total charging capacity of the battery pack and its corresponding second highest single cell voltage are obtained at preset capacity change intervals, and when the battery pack is fully charged, the total charging capacity of the battery pack and its corresponding highest single cell voltage are obtained.

[0140] For example, the preset capacity change amount can be 0.1Ah. Specifically, a 20-dimensional array Array2_maxV can be set. That is, when the total charging capacity of the battery pack changes by 0.1Ah, the second total charging capacity after the 0.1Ah change and the second highest single-cell voltage corresponding to the second total charging capacity are obtained. Each time the condition of a 0.1Ah change in the total charging capacity of the battery pack is triggered, the array is shifted one position to the right, and the new second highest single-cell voltage is filled into the first element of the array, until the data at the 20th position is replaced by the data at the 19th position. And the second total charging capacity of the battery pack at the last time the condition of a preset capacity change was triggered is recorded as Cap2_dch_latest.

[0141] S302. Based on each second total charging capacity and its corresponding second highest single cell voltage, and the total charging capacity and its corresponding highest single cell voltage, determine the second mapping relationship between voltage and capacity during the charging process.

[0142] Optionally, the second total charging capacity and the total charging capacity of the battery pack when fully charged can be used as the vertical axis, and the second highest single cell voltage corresponding to each second total charging capacity and the highest single cell voltage when fully charged can be used as the horizontal axis, so that the second mapping relationship between voltage and capacity during the charging process can be obtained.

[0143] Optionally, after determining the second mapping relationship between voltage and capacity during the charging process, the difference in fully charged capacity between each individual cell and the cell with the highest full charge can also be obtained by the following formula (II).

[0144] Optionally, the array Array2_maxV can be used as the horizontal axis, and the index number corresponding to the highest single cell voltage in the array Index_Array_maxV=[0,1,2,3…19] can be used as the vertical axis. The difference in full-charge capacity between each single cell and the highest fully charged single cell can be obtained by formula (II).

[0145] Formula (IV): Array2_dVmax_Cap = 0.1 × LookUpTable(Array2_maxV, Index_Array_maxV, Array2_CellV^') + dCap2_dch

[0146] Here, Array2_CellV^' represents the target charging voltage for each individual cell, LookUpTable is a lookup table function, and linear interpolation is used to calculate the difference in fully charged capacity. If the value exceeds the boundary value, the boundary value is used.

[0147] Figure 4 is a schematic flowchart of a method for determining a target discharge voltage according to an embodiment of this disclosure. As shown in Figure 4, the target discharge voltage is obtained by correcting the actual discharge voltage of a single cell in the vented state, and may include:

[0148] S401. Determine the actual discharge voltage of a single cell in the venting state, the first voltage change of a single cell under preset conditions, and the second voltage change of the single cell with the lowest venting.

[0149] Optionally, in the venting state, the actual discharge voltage Array1_CellV of each individual cell can be measured.

[0150] Optionally, the preset condition refers to setting the current of the battery pack to 0A when the discharge state is met. After a preset duration, such as 1 second, the voltage of each individual cell will change upward. The first voltage change of each individual cell after the preset duration is measured as Array1_dv. This is to reduce the influence of the internal resistance difference of each individual cell on the calculation results. The second voltage change of the lowest discharged individual cell can be represented by Array1_dv[Index_MinV], where Index_MinV is the number of the lowest discharged individual cell.

[0151] S402. Calculate the difference between the first voltage change and the second voltage change.

[0152] Specifically, the first voltage change difference is the first voltage change of a single cell Array1_dv minus the second voltage change of the cell with the lowest discharge level Array1_dv[Index_MinV].

[0153] S403. The difference between the actual discharge voltage of a single cell and the difference between the first voltage change is taken as the target discharge voltage of the single cell.

[0154] Specifically, the target discharge voltage of each individual cell can be obtained by the following formula (III).

[0155] Array1_〖CellV〗^'=Array1_CellV-Array1_dv+Array1_dv[Index_MinV] formula (3)

[0156] In this embodiment, by correcting the actual discharge voltage of a single cell determined in the venting state, the influence of the internal resistance of each single cell on the equalization calculation can be eliminated.

[0157] Figure 5 is a schematic flowchart of a method for determining a target charging voltage according to an embodiment of this disclosure. As shown in Figure 5, the target charging voltage is obtained by correcting the actual charging voltage of a single battery cell when it is fully charged, and may include:

[0158] S501. Determine the actual charging voltage of a single cell when it is fully charged, the third voltage change of a single cell under preset conditions, and the fourth voltage change of a single cell when fully charged.

[0159] Optionally, the actual charging voltage Array2_CellV of each individual cell can be measured when fully charged.

[0160] Optionally, when the battery pack is fully charged, the current is set to 0A. After a preset duration, such as 1 second, the voltage of each individual cell will change downward. The third voltage change of each individual cell after the preset duration is measured as Array2_dv. This is to reduce the impact of the internal resistance difference of each individual cell on the calculation results. The fourth voltage change of the highest fully charged individual cell can be represented by Array2_dv[Index_MaxV], where Index_MaxV is the number of the highest fully charged individual cell.

[0161] S502. Calculate the difference between the second voltage change and the third voltage change and the fourth voltage change.

[0162] Specifically, the second voltage change difference is the third voltage change Array2_dv of the single cell minus the fourth voltage change Array2_dv[Index_MinV] of the highest fully charged single cell.

[0163] S503. The sum of the differences between the actual single cell voltage and the second voltage change is taken as the target charging voltage of the single cell.

[0164] Optionally, the target charging voltage of each individual battery cell can be obtained by the following formula (iv).

[0165] Formula (IV): Array2_CellV^' = Array2_CellV - Array2_dv + Array2_dv[Index_MaxV]

[0166] Optionally, the final total discharge capacity during the discharge process is the last first total discharge capacity of the battery pack obtained at a preset interval of capacity change.

[0167] Optionally, the final total charging capacity during the charging process is the last second total charging capacity of the battery pack obtained at a preset interval of capacity change.

[0168] Optionally, the total capacity of each individual cell is the sum of the total capacity of the battery pack, the difference in fully charged capacity of each individual cell, and the difference in discharged capacity of each individual cell.

[0169] Specifically, the total capacity of each individual cell from the vented state to the fully charged state can be obtained by the following formula (V).

[0170] Formula (5): Array_Q = Q0 + Array1_dVmin_Cap + Array2_dVmax_Cap

[0171] Where Q0 is the total capacity of the battery pack, Array2_dVmax_Cap is the difference in fully charged capacity of each individual battery cell, and Array1_dVmin_Cap is the difference in discharged capacity of each individual battery cell.

[0172] Optionally, the current total capacity of each individual cell is the sum of the differences between the total capacity of the battery pack and the discharge capacity of each individual cell.

[0173] Specifically, the current total capacity of each individual cell can be obtained using the following formula (VI).

[0174] Formula (VI) = Array_QP = Q0 + Array1_dVmin_Cap

[0175] Where Q0 is the total capacity of the battery pack, and Array1_dVmin_Cap is the difference in discharge capacity of each individual battery cell.

[0176] Figure 6 is a flowchart illustrating another battery equalization method provided in this embodiment. As shown in Figure 6, in step S105, the equalization amount of each individual battery is determined based on the total capacity of each individual battery, the current total capacity of each individual battery, and the difference in fully charged capacity. Then, the individual batteries are charged and discharged equally according to their equalization amounts. This process may include:

[0177] S601. Determine the minimum total capacity from the total capacity of each individual cell and determine the minimum current total capacity from the current total capacity of each individual cell.

[0178] The minimum total capacity can be represented by, for example, Qmin, and the minimum current total capacity can be represented by, for example, QPmin.

[0179] S602. Calculate the capacity difference between the minimum total capacity and the minimum current total capacity.

[0180] Specifically, the minimum total capacity minus the minimum current total capacity.

[0181] S603. The difference between the capacity difference and the full-charge capacity difference of the individual cell is used as the equalization amount of the individual cell.

[0182] The equalization amount of a single cell can be represented, for example, by Bal_CaP.

[0183] Specifically, the balance of each individual cell can be obtained by the following formula (VII).

[0184] Formula (VII) for Array_Bal_CaP = Qmin - QPmin - Array2_dVmax_Cap

[0185] Optionally, if the calculated equalization amount of a single battery cell is less than zero, it indicates that the single battery cell needs to be charged. In this embodiment, only the discharge equalization case is considered; therefore, the single battery cell does not need to have equalization discharge enabled.

[0186] Optionally, the calculation using the above formula (VII) is the theoretical equalization quantity. However, in actual equalization, the voltage of individual cells will also vary due to the different internal resistance of individual cells. In order to reduce equalization error, the following conditions should be followed in actual equalization.

[0187] First, if the cell corresponding to the lowest individual cell voltage and the cell corresponding to the highest individual cell voltage are the same cell, then that cell has the smallest total capacity. The battery pack has reached a preliminary equalization state, and generally, further equalization is not required.

[0188] Second, when in the venting state, if the cell corresponding to the lowest single-cell voltage and the cell corresponding to the lowest capacity are the same single-cell cell, then the cell number is recorded as IndexMinVQ. When fully charged, the current voltage Array_CellV1 of each single-cell cell is obtained. If Array_CellV1(i) < Array_CellV1(IndexMinVQ), where i is the cell number, it means that the single-cell cell voltage is low enough that equalization does not need to be initiated for the time being, and the equalization amount of that single-cell cell is set to 0.

[0189] For example, if Cell3 is the cell with the lowest voltage and lowest capacity when it is discharged, and when it is fully charged, the current voltage of Cell1 and Cell4 is lower than the current voltage of Cell3, then Cell1 and Cell4 do not need to start equalization discharge.

[0190] Third, when fully charged, if the cell with the highest single-cell voltage and the cell with the lowest capacity are the same single-cell cell, then the cell number is recorded as IndexMaxVQ. When discharged, the current voltage Array_CellV2 of each single-cell cell is obtained. If Array_CellV2(i)>Array_CellV2(IndexMaxVQ), it means that the single-cell voltage of the cell is high enough and equalization does not need to be enabled for the time being. The equalization amount of the cell is set to 0.

[0191] For example, if Cell2 has the highest voltage and lowest capacity when fully charged, and Cell4 has a higher current voltage than Cell2 when discharged, then Cell4 does not need to activate equalization discharge.

[0192] Fourth, combining the second and third points, we can conclude that when the same single cell is fully charged and discharged, and the single cell with the lowest capacity is also that single cell, the battery pack does not need to activate the equalization state.

[0193] Optionally, based on the above balancing of individual cells, further extensions can be made. Specifically, the balancing amount Array_Bal_CaP1 of each individual cell can be determined according to a preset proportional coefficient KdCapMinMax, the total capacity of each individual cell, and the difference in full-charge capacity between each individual cell and the highest-charged individual cell. Specifically, it can be calculated using the following formula (viii). This proportional coefficient indicates the ratio between the full-charge capacity difference Array2_dVmax_Cap corresponding to the highest-charged individual cell voltage when the lowest-charged individual cell is fully charged and the discharge capacity difference Array1_dVmin_Cap corresponding to the lowest-charged individual cell when it is discharged.

[0194] Array_Bal_CaP1=max(Array2_dVmax_Cap)-Array2_dVmax_Cap+KdCapMinMax*(Array_Q-Qmin) formula (8)

[0195] Optionally, by balancing the amount of each individual cell in this embodiment, the remaining individual cells will not be fully charged or discharged when the battery pack is not fully discharged or fully charged, thereby extending the service life of the battery pack.

[0196] Figure 7 is a battery balancing effect diagram provided by an embodiment of this disclosure. The balancing diagram corresponding to the maximum capacity balancing in Figure 7 is an effect diagram of single-cell battery balancing using the method provided by the embodiment of this disclosure. As can be seen from Figure 7, the balancing amount of each single cell is lower and the balancing efficiency is faster.

[0197] The discharge end equalization method is based on the following formula (IX).

[0198] Formula (IX) for Array_Bal_CaP2 = Array_Bal_CaP1

[0199] The equalization method at the charging end is based on the following formula (x).

[0200] Formula (10) = max(Array2_dVmax_Cap) - Array2_dVmax_Cap

[0201] Figure 8 is a schematic diagram of an apparatus for a battery equalization processing method provided in an embodiment of this disclosure. As shown in Figure 8, the apparatus includes:

[0202] The discharge determination module 701 is configured to determine the discharge capacity difference between each individual cell and the cell with the lowest discharge capacity in the discharge state, based on the target discharge voltage of each individual cell in the discharge state, the first mapping relationship between voltage and capacity during the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the discharge state and the final total discharge capacity during the discharge process; wherein, the target discharge voltage is obtained by correcting the actual discharge voltage of the individual cell in the discharge state, and the cell with the lowest discharge capacity is the individual cell with the lowest actual discharge voltage in the discharge state;

[0203] The charging determination module 702 is configured to determine the full-capacity difference between each individual cell and the highest-charged individual cell when fully charged, based on the target charging voltage of each individual cell when fully charged, the second mapping relationship between voltage and capacity during the charging process, and the charging capacity difference between the total charging capacity of the battery pack when fully charged and the final total charging capacity during the charging process; wherein, the target charging voltage is obtained by correcting the actual charging voltage of the individual cell when fully charged, and the highest-charged individual cell is the individual cell with the highest actual charging voltage when fully charged;

[0204] The capacity determination module 703 is configured to determine the total capacity of each individual cell from the vented state to the fully charged state based on the vented capacity difference, the fully charged capacity difference, and the total capacity of the battery pack, and to determine the current total capacity of each individual cell in the fully charged state based on the vented capacity difference and the total capacity of the battery pack.

[0205] The balancing module 704 is configured to determine the balancing amount of each individual battery based on the total capacity of each individual battery, the current total capacity of each individual battery, and the difference in the fully charged capacity of each individual battery, and to perform charge-discharge balancing on each individual battery based on the balancing amount of each individual battery.

[0206] Optionally, the discharge determination module 701 is specifically configured as follows:

[0207] Determine the actual discharge voltage before correction to the target discharge voltage based on the target discharge voltage;

[0208] Based on the first mapping relationship between voltage and capacity during the discharge process, the discharge capacity corresponding to the actual discharge voltage is determined, and the discharge capacity is used as the first target capacity corresponding to the target discharge voltage.

[0209] The sum of the difference between the first target capacity and the discharge capacity is taken as the venting capacity difference;

[0210] Optionally, the charging determination module 702 is specifically configured as follows:

[0211] Determine the actual charging voltage before correction to the target charging voltage based on the target charging voltage;

[0212] Based on the second mapping relationship between voltage and capacity during the charging process, the charging capacity corresponding to the actual charging voltage is determined, and the charging capacity is used as the second target capacity corresponding to the target charging voltage.

[0213] The sum of the difference between the second target capacity and the charging capacity is taken as the full charge capacity difference.

[0214] Optionally, the discharge determination module 701 is specifically configured as follows:

[0215] During the discharge process of the battery pack, the first total discharge capacity of the battery pack and its corresponding first minimum single cell voltage are obtained at preset capacity change intervals. When the battery pack is in a discharged state, the total discharge capacity of the battery pack and its corresponding minimum single cell voltage are obtained.

[0216] Based on each first total discharge capacity and its corresponding first minimum single cell voltage, and the total discharge capacity and its corresponding minimum single cell voltage, determine the first mapping relationship between the voltage and capacity during the discharge process;

[0217] Optionally, the charging determination module 702 is specifically configured as follows:

[0218] During the charging process of the battery pack, the second total charging capacity of the battery pack and its corresponding second highest single cell voltage are obtained at preset capacity change intervals; when the battery pack is fully charged, the total charging capacity of the battery pack and its corresponding highest single cell voltage are obtained.

[0219] Based on each second total charging capacity and its corresponding second highest single cell voltage, and the total charging capacity and its corresponding highest single cell voltage, a second mapping relationship between voltage and capacity is determined during the charging process.

[0220] Optionally, the discharge determination module 701 is specifically configured as follows:

[0221] Determine the actual discharge voltage of the single cell when it is in a discharged state, the first voltage change of the single cell under preset conditions, and the second voltage change of the single cell with the lowest discharge.

[0222] Calculate the difference between the first voltage change and the second voltage change;

[0223] The difference between the actual single-cell voltage of the single cell and the difference between the first voltage change is taken as the target discharge voltage of the single cell.

[0224] Optionally, the charging determination module 701 is specifically configured as follows:

[0225] The actual charging voltage of the single cell when it is fully charged, the third voltage change of the single cell under preset conditions, and the fourth voltage change of the single cell with the highest charge are determined.

[0226] Calculate the difference between the third voltage change and the fourth voltage change;

[0227] The sum of the difference between the actual single-cell voltage and the second voltage change is taken as the target charging voltage of the single-cell battery.

[0228] Optionally, the final total discharge capacity during the discharge process is the last first total discharge capacity of the battery pack obtained by the preset capacity change at the interval.

[0229] The final total charging capacity during the charging process is the last second total charging capacity of the battery pack obtained by the preset capacity change amount at the interval.

[0230] Optionally, the total capacity of each individual battery is the sum of the total capacity of the battery pack, the difference in fully charged capacity of each individual battery, and the difference in discharged capacity of each individual battery.

[0231] The current total capacity of each individual battery cell is the sum of the differences between the total capacity of the battery pack and the discharge capacity of each individual battery cell.

[0232] Optionally, the equalization module 704 is specifically configured as follows:

[0233] Determine the minimum total capacity from the total capacity of each of the individual cells and determine the minimum current total capacity from the current total capacity of each of the individual cells;

[0234] Calculate the capacity difference between the minimum total capacity and the minimum current total capacity;

[0235] The difference between the capacity difference and the full-charge capacity difference corresponding to the individual cell is used as the equalization amount of the individual cell.

[0236] Figure 9 is a structural block diagram of an electronic device 800 provided in an embodiment of this disclosure. This electronic device can, for example, be the battery equalization processor described in the foregoing embodiments. As shown in Figure 9, the electronic device may include: a processor 801 and a memory 802.

[0237] Optionally, a bus 803 may also be included, wherein the memory 802 is used to store machine-readable instructions executable by the processor 801. When the electronic device 800 is running, the processor 801 and the memory 802 communicate via the bus 803. When the machine-readable instructions are executed by the processor 801, the method steps in the above method embodiments are performed.

[0238] This disclosure also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the method steps described in the battery balancing method embodiments.

[0239] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems and devices described above can be referred to the corresponding processes in the method embodiments, and will not be repeated here. In the several embodiments provided in this disclosure, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection may be through some communication interfaces; the indirect coupling or communication connection of devices or modules may be electrical, mechanical, or other forms.

[0240] Furthermore, the functional units in the various embodiments of this disclosure can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. If the functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this disclosure, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this disclosure. The aforementioned storage medium includes: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media capable of storing program code.

[0241] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Industrial applicability

[0242] Using the above scheme, when determining the discharge capacity difference between each individual cell and the lowest discharged cell in the discharged state, it is based on the target discharge voltage of each individual cell in the discharged state, the first mapping relationship between voltage and capacity during discharge, and the discharge capacity difference between the total discharge capacity of the battery pack in the discharged state and the final total discharge capacity during discharge. This process takes into account the correlation between voltage characteristics and capacity during battery discharge, making the obtained discharge capacity differences more reasonable. Similarly, when determining the full charge capacity difference between each individual cell and the highest fully charged cell in the fully charged state, the correlation between voltage characteristics and capacity during charging is considered, making the obtained full charge capacity differences more reasonable. This approach is more reasonable. When determining the total capacity of each individual cell from the discharged state to the fully charged state, the differences in total capacity between individual cells when fully charged and when discharged are taken into account, resulting in a more reasonable total capacity for each individual cell. When determining the current total capacity of each individual cell when fully charged, the difference in discharge capacity between each individual cell when discharged and the cell with the lowest discharge capacity is taken into account, resulting in a more reasonable current total capacity for each individual cell. Therefore, balancing based on the balance of each individual cell obtained from the aforementioned total capacity, current total capacity, and differences in fully charged capacity can achieve better balancing results and improve the lifespan of the battery pack.

Claims

1. A battery equalization processing method, wherein, The method for balancing the charge and discharge of individual cells in a battery pack includes: Based on the target discharge voltage of each individual cell in the venting state, the first mapping relationship between voltage and capacity during the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the venting state and the final total discharge capacity during the discharge process, the discharge capacity difference between each individual cell and the individual cell with the lowest discharge capacity in the venting state is determined; wherein, the target discharge voltage is obtained by correcting the actual discharge voltage of the individual cell in the venting state, and the individual cell with the lowest discharge capacity is the individual cell with the lowest actual discharge voltage in the venting state. Based on the target charging voltage of each individual cell when fully charged, the second mapping relationship between voltage and capacity during the charging process, and the difference in charging capacity between the total charging capacity of the battery pack when fully charged and the final total charging capacity during the charging process, the full-charge capacity difference between each individual cell and the cell with the highest full charge when fully charged is determined; wherein, the target charging voltage is obtained by correcting the actual charging voltage of the individual cell when fully charged, and the cell with the highest full charge is the individual cell with the highest actual charging voltage when fully charged; The total capacity of each individual cell from the vented state to the fully charged state is determined based on the vented capacity difference, the fully charged capacity difference, and the total capacity of the battery pack. Based on the difference in venting capacity of each individual cell and the total capacity of the battery pack, determine the current total capacity of each individual cell when fully charged. Based on the total capacity of each individual battery cell, the current total capacity of each individual battery cell, and the difference in fully charged capacity of each individual battery cell, the equalization amount of each individual battery cell is determined, and the charge and discharge equalization of each individual battery cell is performed based on the equalization amount of each individual battery cell.

2. The battery equalization processing method according to claim 1, wherein, The step of determining the discharge capacity difference between each individual cell and the cell with the lowest discharge capacity in the discharge state, based on the target discharge voltage of each individual cell in the discharge state, the first mapping relationship between voltage and capacity during the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the discharge state and the final total discharge capacity during the discharge process, includes: Determine the actual discharge voltage before correction to the target discharge voltage based on the target discharge voltage; Based on the first mapping relationship between voltage and capacity during the discharge process, the discharge capacity corresponding to the actual discharge voltage is determined, and the discharge capacity is used as the first target capacity corresponding to the target discharge voltage. The sum of the difference between the first target capacity and the discharge capacity is taken as the venting capacity difference.

3. The battery equalization processing method according to claim 2, wherein, The step of determining the difference in charging capacity between each individual cell and the highest-charged cell when fully charged, based on the target charging voltage of each individual cell when fully charged, the second mapping relationship between voltage and capacity during the charging process, and the difference in charging capacity between the total charging capacity of the battery pack when fully charged and the final total charging capacity during the charging process, includes: Determine the actual charging voltage before correction to the target charging voltage based on the target charging voltage; Based on the second mapping relationship between voltage and capacity during the charging process, the charging capacity corresponding to the actual charging voltage is determined, and the charging capacity is used as the second target capacity corresponding to the target charging voltage. The sum of the difference between the second target capacity and the charging capacity is taken as the full charge capacity difference.

4. The battery equalization processing method according to claim 1, wherein, The first mapping relationship between voltage and capacity during the discharge process is determined through the following steps: During the discharge process of the battery pack, the first total discharge capacity of the battery pack and its corresponding first minimum single cell voltage are obtained at preset capacity change intervals. When the battery pack is in a discharged state, the total discharge capacity of the battery pack and its corresponding minimum single cell voltage are obtained. Based on the first total discharge capacity and its corresponding first minimum single cell voltage, and the total discharge capacity and its corresponding minimum single cell voltage, a first mapping relationship between voltage and capacity during the discharge process is determined.

5. The battery equalization processing method according to claim 1, wherein, The second mapping relationship between voltage and capacity during the charging process is determined through the following steps: During the charging process of the battery pack, the second total charging capacity of the battery pack and its corresponding second highest single cell voltage are obtained at preset capacity change intervals; when the battery pack is fully charged, the total charging capacity of the battery pack and its corresponding highest single cell voltage are obtained. Based on each second total charging capacity and its corresponding second highest single cell voltage, and the total charging capacity and its corresponding highest single cell voltage, a second mapping relationship between voltage and capacity is determined during the charging process.

6. The battery equalization processing method according to claim 4, wherein, The target discharge voltage is obtained by correcting the actual discharge voltage of the single cell in the vented state, including: Determine the actual discharge voltage of the single cell when it is in a discharged state, the first voltage change of the single cell under preset conditions, and the second voltage change of the single cell with the lowest discharge. Calculate the difference between the first voltage change and the second voltage change; The difference between the actual single-cell voltage of the single cell and the difference between the first voltage change is taken as the target discharge voltage of the single cell.

7. The battery equalization processing method according to claim 5, wherein, The target charging voltage is obtained by correcting the actual charging voltage of the single cell when it is fully charged, including: The actual charging voltage of the single cell when it is fully charged, the third voltage change of the single cell under preset conditions, and the fourth voltage change of the single cell with the highest charge are determined. Calculate the difference between the third voltage change and the fourth voltage change; The sum of the difference between the actual single-cell voltage and the second voltage change is taken as the target charging voltage of the single-cell battery.

8. The battery equalization processing method according to claim 4, wherein, The final total discharge capacity during the discharge process is the last first total discharge capacity of the battery pack obtained by the preset capacity change at the interval. The final total charging capacity during the charging process is the last second total charging capacity of the battery pack obtained by the preset capacity change amount at the interval.

9. The battery equalization processing method according to claim 1, wherein, The total capacity of each individual battery is the sum of the total capacity of the battery pack, the difference in the fully charged capacity of each individual battery, and the difference in the discharged capacity of each individual battery. The current total capacity of each individual battery cell is the sum of the differences between the total capacity of the battery pack and the discharge capacity of each individual battery cell.

10. The battery equalization processing method according to claim 1, wherein, The step of determining the balancing amount of each individual battery cell based on the total capacity of each individual battery cell, the current total capacity of each individual battery cell, and the difference in fully charged capacity of each individual battery cell includes: Determine the minimum total capacity from the total capacity of each of the individual cells and determine the minimum current total capacity from the current total capacity of each of the individual cells; Calculate the capacity difference between the minimum total capacity and the minimum current total capacity; The difference between the capacity difference and the full-charge capacity difference corresponding to the individual cell is used as the equalization amount of the individual cell.

11. The battery equalization processing method according to claim 1, wherein, The venting capacity difference is calculated using the following formula: Array1_dVmin_Cap=0.1×LookUpTable(Array1_minV, Index_Array_minV, Array1_CellV^')+dCap1_dch; Wherein, Array1_dVmin_Cap is the discharge capacity difference, Array1_minV is an array including the first minimum single cell voltage corresponding to the first total discharge capacity of each battery pack at preset capacity changes, Index_Array_minV is the index number corresponding to each first minimum single cell voltage in the array, and dCap1_dch is the discharge capacity difference.

12. The battery equalization processing method according to claim 1, wherein, The full capacity difference is calculated using the following formula; Array2_dVmax_Cap=0.1×LookUpTable(Array2_maxV, Index_Array_maxV, Array2_CellV^')+dCap2_dch; Wherein, Array2_maxV is an array containing the second highest single cell voltage corresponding to each second total charging capacity of the battery pack at preset capacity changes, Index_Array_maxV is the index number corresponding to each second highest single cell voltage, and dCap2_dch is the charging capacity difference.

13. A battery equalization processing device, wherein, include: The discharge determination module is configured to determine the discharge capacity difference between each individual cell and the cell with the lowest discharge capacity in the discharge state, based on the target discharge voltage of each individual cell in the discharge state, the first mapping relationship between voltage and capacity during the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the discharge state and the final total discharge capacity during the discharge process; wherein, the target discharge voltage is obtained by correcting the actual discharge voltage of the individual cell in the discharge state, and the cell with the lowest discharge capacity is the individual cell with the lowest actual discharge voltage in the discharge state; The charging determination module is configured to determine the full-capacity difference between each individual cell and the highest-charged individual cell when fully charged, based on the target charging voltage of each individual cell when fully charged, the second mapping relationship between voltage and capacity during the charging process, and the charging capacity difference between the total charging capacity of the battery pack when fully charged and the final total charging capacity during the charging process; wherein, the target charging voltage is obtained by correcting the actual charging voltage of the individual cell when fully charged, and the highest-charged individual cell is the individual cell with the highest actual charging voltage when fully charged; The capacity determination module is configured to determine the total capacity of each individual cell from the vented state to the fully charged state based on the vented capacity difference, the fully charged capacity difference, and the total capacity of the battery pack, and to determine the current total capacity of each individual cell in the fully charged state based on the vented capacity difference and the total capacity of the battery pack. The balancing module is configured to determine the balancing amount of each individual battery based on the total capacity of each individual battery, the current total capacity of each individual battery, and the difference in the fully charged capacity of each individual battery, and to perform charge-discharge balancing on each individual battery based on the balancing amount of each individual battery.

14. An electronic device, wherein, The device includes a memory and a processor, wherein the memory stores a computer program executable by the processor, and the processor executes the computer program to implement the steps of the battery equalization processing method according to any one of claims 1-12.

15. A computer-readable storage medium, wherein, The computer-readable storage medium stores a computer program that, when executed by a processor, performs the steps of the battery equalization processing method as described in any one of claims 1-12.

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