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

Abstract

The invention provides a battery equalization processing method and device, electronic equipment and a storage medium, and the method comprises the steps: determining an emptying capacity difference value between each single battery and an emptying lowest single battery in an emptying state; determining a full capacity difference value between each single battery and the highest full single battery in a full state; determining the total capacity of each single battery from the emptying state to the full state; determining the current total capacity of each single battery in a fully charged state; and determining the equalization quantity of each single battery according to the total capacity of each single battery, the current total capacity of each single battery and each full capacity difference value, and carrying out charge-discharge equalization on each single battery according to the equalization quantity of each single battery. Through the incidence relation between the voltage characteristics and the capacity, the determined emptying capacity difference and the full capacity difference are more reasonable, so that the determined equalization quantity of each single battery is more accurate, and the equalization effect of each single battery is better.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery balancing processing method, device, electronic device and storage medium. Background Art

[0002] For large energy storage systems, such as electric vehicles and energy storage boxes, multiple cells are required to be connected in series. Due to different production processes, grouping technologies, and aging paths, the differences in cell capacity, voltage, internal resistance, etc. will gradually increase with aging. If not intervened in time, the available capacity of the battery pack will be severely reduced, shortening the service life of the battery pack. In order to fully utilize the charging and discharging performance of the battery pack and slow down the life decay, it is necessary to dynamically adjust the remaining capacity of each battery.

[0003] In the prior art, commonly used balancing solutions include capacity balancing and voltage balancing. Capacity balancing mainly identifies the battery cell with the lowest capacity and calculates the capacity difference between other battery cells and the battery cell with the lowest capacity. When the capacity difference is less than a certain threshold, the balancing discharge is stopped. Voltage balancing mainly identifies the battery cell with the lowest voltage difference and calculates the voltage difference between the remaining battery cells and the battery cell with the lowest voltage difference. When the voltage difference is less than a certain threshold, the balancing discharge is stopped. These two methods are unreasonable in calculating the balancing amount and the balancing stop conditions are also unreasonable, resulting in poor battery balancing effect, which leads to a short battery life. Summary of the invention

[0004] The purpose of the present application is to provide a battery balancing processing method, device, electronic device and storage medium to improve the accuracy of battery balancing processing in view of the above-mentioned deficiencies in the prior art.

[0005] To achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0006] In a first aspect, an embodiment of the present application provides a battery balancing processing method for performing charge and discharge balancing on each single cell in a battery pack, the method comprising:

[0007] Determine the empty capacity difference between each single cell and the lowest empty single cell in the empty state according to the target discharge voltage of each single cell in the empty state, the first mapping relationship between voltage and capacity in the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the empty state and the last total discharge capacity in the discharge process; wherein the target discharge voltage is obtained by correcting the actual discharge voltage of the single cell in the empty state, and the lowest empty single cell is the single cell with the lowest actual discharge voltage in the empty state;

[0008] According to the target charging voltage of each of the single cells in the full state, the second mapping relationship between the voltage and the capacity during the charging process, and the charging capacity difference between the total charging capacity of the battery pack in the full state and the final total charging capacity during the charging process, the full capacity difference between each of the single cells and the highest-full single cell in the full state is determined; wherein the target charging voltage is obtained by correcting the actual charging voltage of the single cells in the full state, and the highest-full single cell is the single cell with the highest actual charging voltage in the full state;

[0009] Determine the total capacity of each of the single cells from the empty state to the full state according to each of the empty capacity differences, each of the full capacity differences and the total capacity of the battery pack;

[0010] Determining the current total capacity of each of the single cells when in a fully charged state according to each of the empty capacity differences and the total capacity of the battery pack;

[0011] The balancing amount of each single cell is determined according to the total capacity of each single cell, the current total capacity of each single cell and the full capacity difference, and the charge and discharge balancing of each single cell is performed according to the balancing amount of each single cell.

[0012] Optionally, the step of determining the empty capacity difference between each single cell and the lowest-emptied single cell in the empty state according to the target discharge voltage of each single cell in the empty state, the first mapping relationship between the voltage and the capacity in the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the empty state and the last total discharge capacity in the discharge process includes:

[0013] Determining, according to the target discharge voltage, an actual discharge voltage before correction of the target discharge voltage;

[0014] Determining a discharge capacity corresponding to the actual discharge voltage according to a first mapping relationship between the voltage and the capacity during the discharge process, and using the discharge capacity as a first target capacity corresponding to the target discharge voltage;

[0015] The sum of the first target capacity and the difference between the discharge capacity is used as the discharge capacity difference;

[0016] Optionally, the determining, according to the target charging voltage of each of the single cells in the full state, the second mapping relationship between the voltage and the capacity during the charging process, and the charging capacity difference between the total charging capacity of the battery pack in the full state and the last total charging capacity during the charging process, the full capacity difference between each of the single cells and the highest-charged single cell in the full state includes:

[0017] Determining, according to the target charging voltage, an actual charging voltage before correction of the target charging voltage;

[0018] Determine, according to a second mapping relationship between voltage and capacity during the charging process, a charging capacity corresponding to the actual charging voltage, and use the charging capacity as a second target capacity corresponding to the target charging voltage;

[0019] The sum of the second target capacity and the charge capacity difference is used as the full charge capacity difference.

[0020] Optionally, the first mapping relationship between voltage and capacity during the discharge process is determined by the following steps:

[0021] During the discharge process of the battery pack, obtaining each first total discharge capacity of the battery pack and its corresponding first minimum single cell voltage at intervals of a preset capacity change, and obtaining the total discharge capacity of the battery pack and its corresponding minimum single cell voltage when the battery pack is in an empty state;

[0022] Determining a first mapping relationship between the voltage and the capacity during the discharge process according to 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;

[0023] Optionally, the second mapping relationship between the voltage and the capacity during the charging process is determined by the following steps:

[0024] During the charging process of the battery pack, the second total charging capacity of the battery pack and the corresponding second highest single cell voltage are obtained at intervals of a preset capacity change; when the battery pack is in a fully charged state, the total charging capacity of the battery pack and the corresponding highest single cell voltage are obtained;

[0025] A second mapping relationship between voltage and capacity during the charging process is determined according to 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.

[0026] Optionally, the target discharge voltage is obtained by correcting the actual discharge voltage of the single battery in an empty state, including:

[0027] Determine the actual discharge voltage of the single cell when it is in an empty state, the first voltage change of the single cell under a preset condition, and the second voltage change of the lowest empty single cell;

[0028] Calculating a first voltage change difference between the first voltage change and the second voltage change;

[0029] The difference between the actual single cell voltage of the single cell and the first voltage variation difference is used as the target discharge voltage of the single cell.

[0030] Optionally, the target charging voltage is obtained by correcting the actual charging voltage of the single battery when it is in a fully charged state, including:

[0031] Determine 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 highest single cell when it is fully charged;

[0032] Calculating a second voltage change difference between the third voltage change and the fourth voltage change;

[0033] The sum of the actual single cell voltage of the single cell and the difference between the second voltage change amount is used as the target charging voltage of the single cell.

[0034] Optionally, the last total discharge capacity in the discharge process is the last first total discharge capacity of the battery pack obtained by the interval preset capacity change;

[0035] The final total charging capacity during the charging process is the last second total charging capacity of the battery pack obtained by the interval preset capacity change.

[0036] Optionally, the total capacity of each of the single cells is the sum of the total capacity of the battery pack, the difference between the full capacities of each of the single cells, and the difference between the empty capacities of each of the single cells;

[0037] The current total capacity of each single cell is the sum of the total capacity of the battery pack and the difference between the discharged capacities of each single cell.

[0038] Optionally, determining the balancing amount of each of the single cells according to the total capacity of each of the single cells, the current total capacity of each of the single cells, and each of the full capacity differences includes:

[0039] Determining a minimum total capacity from the total capacities of the single cells and determining a minimum current total capacity from the current total capacities of the single cells;

[0040] Calculating a capacity difference between the minimum total capacity and the minimum current total capacity;

[0041] The difference between the capacity difference and the full capacity difference corresponding to the single cell is used as the balancing amount of the single cell.

[0042] In a second aspect, an embodiment of the present application further provides a battery balancing processing device, the device comprising:

[0043] a discharge determination module, for determining, in the empty state, the empty capacity difference between each single cell and the lowest empty single cell according to the target discharge voltage of each single cell in the empty state, the first mapping relationship between voltage and capacity in the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the empty state and the last total discharge capacity in the discharge process; wherein the target discharge voltage is obtained by correcting the actual discharge voltage of the single cell in the empty state, and the lowest empty single cell is the single cell with the lowest actual discharge voltage in the empty state;

[0044] A charging determination module, for determining the full capacity difference between each of the single cells and the highest-full single cell in the full state according to the target charging voltage of each of the single cells in the full state, the second mapping relationship between the voltage and the capacity in the charging process, and the charging capacity difference between the total charging capacity of the battery pack in the full state and the last total charging capacity in the charging process; wherein the target charging voltage is obtained by correcting the actual charging voltage of the single cells in the full state, and the highest-full single cell is the single cell with the highest actual charging voltage in the full state;

[0045] a capacity determination module, for determining the total capacity of each of the single cells from an empty state to a full state according to each of the empty capacity differences, each of the full capacity differences and the total capacity of the battery pack, and for determining the current total capacity of each of the single cells in a full state according to each of the empty capacity differences and the total capacity of the battery pack;

[0046] The balancing module is used to determine the balancing amount of each single cell according to the total capacity of each single cell, the current total capacity of each single cell and the full capacity difference, and to balance the charge and discharge of each single cell according to the balancing amount of each single cell.

[0047] Optionally, the discharge determination module is specifically used to:

[0048] Determining, according to the target discharge voltage, an actual discharge voltage before correction of the target discharge voltage;

[0049] Determining a discharge capacity corresponding to the actual discharge voltage according to a first mapping relationship between the voltage and the capacity during the discharge process, and using the discharge capacity as a first target capacity corresponding to the target discharge voltage;

[0050] The sum of the first target capacity and the difference between the discharge capacity is used as the discharge capacity difference;

[0051] Optionally, the charging determination module is specifically used to:

[0052] Determining, according to the target charging voltage, an actual charging voltage before correction of the target charging voltage;

[0053] Determine, according to a second mapping relationship between voltage and capacity during the charging process, a charging capacity corresponding to the actual charging voltage, and use the charging capacity as a second target capacity corresponding to the target charging voltage;

[0054] The sum of the second target capacity and the charge capacity difference is used as the full charge capacity difference.

[0055] Optionally, the discharge determination module is specifically used to:

[0056] During the discharge process of the battery pack, obtaining each first total discharge capacity of the battery pack and its corresponding first minimum single cell voltage at intervals of a preset capacity change, and obtaining the total discharge capacity of the battery pack and its corresponding minimum single cell voltage when the battery pack is in an empty state;

[0057] Determining a first mapping relationship between the voltage and the capacity during the discharge process according to 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;

[0058] Optionally, the charging determination module is specifically used to:

[0059] During the charging process of the battery pack, the second total charging capacity of the battery pack and the corresponding second highest single cell voltage are obtained at intervals of a preset capacity change; when the battery pack is in a fully charged state, the total charging capacity of the battery pack and the corresponding highest single cell voltage are obtained;

[0060] A second mapping relationship between voltage and capacity during the charging process is determined according to 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.

[0061] Optionally, the discharge determination module is specifically used to:

[0062] In the empty state, determining the actual discharge voltage of the single cell, the first voltage change of the single cell under a preset condition, and the second voltage change of the lowest empty single cell;

[0063] Calculating a first voltage change difference between the first voltage change and the second voltage change;

[0064] The difference between the actual single cell voltage of the single cell and the first voltage variation difference is used as the target discharge voltage of the single cell.

[0065] Optionally, the charging determination module is specifically used to:

[0066] When the battery is fully charged, determine the actual charging voltage of the single cell, the third voltage change of the single cell under a preset condition, and the fourth voltage change of the highest single cell when the battery is fully charged;

[0067] Calculating a second voltage change difference between the third voltage change and the fourth voltage change;

[0068] The sum of the actual single cell voltage of the single cell and the difference between the second voltage change amount is used as the target charging voltage of the single cell.

[0069] Optionally, the last total discharge capacity in the discharge process is the last first total discharge capacity of the battery pack obtained by the interval preset capacity change;

[0070] The final total charging capacity during the charging process is the last second total charging capacity of the battery pack obtained by the interval preset capacity change.

[0071] Optionally, the total capacity of each of the single cells is the sum of the total capacity of the battery pack, the difference between the full capacities of each of the single cells, and the difference between the empty capacities of each of the single cells;

[0072] The current total capacity of each single cell is the sum of the total capacity of the battery pack and the difference between the discharged capacities of each single cell.

[0073] Optionally, the balancing module is specifically used for:

[0074] Determining a minimum total capacity from the total capacities of the single cells and determining a minimum current total capacity from the current total capacities of the single cells;

[0075] Calculating a capacity difference between the minimum total capacity and the minimum current total capacity;

[0076] The difference between the capacity difference and the full capacity difference corresponding to the single cell is used as the balancing amount of the single cell.

[0077] In a third aspect, an embodiment of the present application further provides an electronic device, comprising: a processor, a storage medium and a bus, wherein the storage medium stores program instructions executable by the processor, and when an application is running, 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 above.

[0078] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored, and the computer program is read and executes the steps of the battery balancing processing method described in the first aspect.

[0079] The beneficial effects of this application are:

[0080] The present application provides a battery balancing processing method, device, electronic device and storage medium. When determining the empty capacity difference between each single cell and the lowest empty single cell in the empty state, the empty capacity difference is determined according to the target discharge voltage of each single cell in the empty state, the mapping relationship between the voltage and the capacity during the emptying process, and the difference in the total discharge capacity of the battery pack in the empty state. In this process, the correlation between the voltage characteristics and the capacity during the emptying process of the battery is taken into account, so that each empty capacity difference obtained can be more reasonable; at the same time, when determining the full capacity difference between each single cell and the highest filled single cell in the full state, the correlation between the voltage characteristics and the capacity during the fulling process is taken into account, so that each full capacity difference obtained can also be more reasonable. Reasonable; when determining the total capacity of each single cell from the empty state to the full state, the difference in total capacity between each single cell when full and the difference in total capacity between each single cell when empty are taken into account, so that the total capacity of each single cell obtained is more reasonable; when determining the current total capacity of each single cell in the full state, the difference in empty capacity between each single cell and the lowest empty single cell in the empty state is taken into account, so that the current total capacity of each single cell obtained is more reasonable; therefore, balancing based on the additional discharge capacity of each single cell obtained according to the total capacity of each single cell, the current total capacity of each single cell and the difference in full capacity mentioned above can make the balancing effect better and improve the service life of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0082] Figure 1 A flowchart of a battery balancing method provided in an embodiment of the present application;

[0083] Figure 2 A schematic diagram of a process for determining a mapping relationship provided in an embodiment of the present application;

[0084] Figure 3A schematic diagram of another process for determining a mapping relationship provided in an embodiment of the present application;

[0085] Figure 4 A schematic diagram of a process for determining a target discharge voltage provided in an embodiment of the present application;

[0086] Figure 5 A schematic diagram of a process for determining a target charging voltage provided in an embodiment of the present application;

[0087] Figure 6 A flowchart of another battery balancing method provided in an embodiment of the present application;

[0088] Figure 7 A battery balancing effect diagram provided in an embodiment of the present application;

[0089] Figure 8 A schematic diagram of a battery balancing method provided in an embodiment of the present application;

[0090] Fig. 9 A structural block diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0091] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart under the guidance of the content of the present application, or remove one or more operations from the flowchart.

[0092] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0093] It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the existence of the features declared thereafter, but does not exclude the addition of other features.

[0094] For battery packs, commonly used balancing solutions include capacity balancing and voltage balancing.

[0095] Among them, voltage equalization can generally be performed by comparing the voltage difference between each single cell voltage and the lowest single cell voltage in the battery pack after charging. If the voltage difference between the single cell voltage and the lowest single cell voltage is greater than a certain threshold, the single cell corresponding to the single cell voltage is discharged. If the voltage difference between the single cell voltage and the lowest single cell voltage is lower than a certain threshold, the equalization stops. This method can only be used in the static state after charging is completed, and because it only considers the voltage difference after charging is completed, while ignoring the inconsistency of the capacity between the single cells, it will cause equalization misoperation. This is because the highest single cell voltage after charging is completed may also be the lowest single cell voltage at the end of discharging. At this time, the capacity of the battery pack has reached the maximum value. At this time, if the highest single cell voltage is discharged evenly, it will only have a counterproductive effect.

[0096] Capacity balancing is generally achieved by identifying the capacity difference between cells and comparing the capacity of each cell with the capacity of the lowest cell. If the difference between the capacity of a cell and the capacity of the lowest cell is greater than 1% of the capacity corresponding to the state of charge, balancing is turned on, otherwise, balancing is turned off. This method generally assumes that the total capacity of each cell is consistent, ignoring the difference in capacity when the cells are fully charged, which will lead to a lot of unexpected balancing, and the cell with the lowest capacity is not necessarily the cell with the lowest voltage. When the initial state of charge of the cell is high, it also needs to be discharged for balancing.

[0097] Based on the above description of the prior art, it can be seen that the calculation of the balancing amount in the two methods in the prior art is unreasonable and the balancing stop conditions are also unreasonable.

[0098] Therefore, the present application proposes a battery balancing processing method, which performs balancing according to the voltage characteristics and capacity statistics when the battery is fully charged and discharged, thereby ensuring the high efficiency of balancing and effectively improving the service life of the battery pack.

[0099] Optionally, the battery equalization processing method provided in the embodiment of the present application is applied to an electronic device, which may be, for example, a terminal device with computing and display capabilities, such as a mobile phone, a tablet computer, a laptop computer, a PDA, a desktop computer, or a server. Specifically, it can be applied to applications in terminal devices, such as: APP (application, mobile phone software) of a mobile phone, an application system on a computer, etc. When the execution subject is a server, it can communicate with a measuring device that measures the charging and discharging process of a battery pack through wireless communication, obtain the data of the battery pack measured by the measuring device during the charging and discharging process, and then use the battery equalization processing method provided in the embodiment of the present application to obtain the additional discharge capacity of each single cell, so as to balance the charge and discharge of each single cell.

[0100] The specific implementation process of the battery balancing process provided in the embodiment of the present application is explained in detail below.

[0101] Figure 1 The present invention provides a flow chart of a battery balancing method provided in an embodiment of the present invention. The method is performed by the electronic device mentioned above, and is used to balance the charge and discharge of each single cell in the battery pack. Figure 1 As shown, the method includes:

[0102] S101, determining the empty capacity difference between each single cell and the lowest-discharged single cell in the empty state according to the target discharge voltage of each single cell in the empty state, the first mapping relationship between the voltage and the capacity in the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the empty state and the last total discharge capacity in the discharge process.

[0103] The battery pack includes at least one single cell, which is composed of single cells connected in series. The target discharge voltage refers to the correction of the actual discharge voltage of the single cell in the empty state, and the actual discharge voltage refers to the voltage measurement of the single cell in the empty state. The target discharge voltage can be represented by Array1_CellV′, and the actual discharge voltage can be represented by Array1_CellV. The lowest empty single cell refers to the single cell with the lowest actual discharge voltage in the empty state.

[0104] 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 single cell of the battery pack during the discharge process and the discharge capacity of the battery pack. When determining the empty capacity difference between each single cell in the empty state and the empty lowest single cell, not only the target discharge voltage of each single cell in the empty state is taken into account, but also the characteristic relationship between voltage and capacity during the discharge process is taken into account. Compared with the prior art that only considers the voltage difference or capacity difference at the end of discharge, the determined empty capacity difference in the empty state can be made more reasonable.

[0105] Among them, the total discharge capacity of the battery pack is represented by Cap1_dch when it is in the empty state, and the last total discharge capacity in the discharge process is represented by Cap1_dch_latest. Then the discharge capacity difference dCap1_dch between the total discharge capacity of the battery pack in the empty state and the last total discharge capacity in the discharge process is the difference between Cap1_dch and Cap1_dch_latest. The last total discharge capacity in the empty process refers to the total capacity of the battery pack when the preset capacity change amount described below is triggered for the last time in the discharge process. This is because the change in the total discharge capacity of the battery pack in the empty state and the last total discharge capacity may not be the preset capacity change amount described above. For example, the difference between Cap1_dch and Cap1_dch_latest may not be 0.1Ah.

[0106] S102, determining the full capacity difference between each single cell and the highest-charged single cell in the full state according to the target charging voltage of each single cell in the full state, 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 in the full state and the final total charging capacity in the charging process.

[0107] The highest fully charged single cell refers to the single cell with the highest actual charging voltage when fully charged. The target charging voltage refers to the voltage obtained by correcting the actual charging voltage of the single cell when fully charged, and the actual charging voltage refers to the voltage measured when the single cell is fully charged. The target charging voltage can be represented by Array2_CellV′, and the actual charging voltage can be represented by Array2_CellV.

[0108] Optionally, the second mapping relationship between voltage and capacity during the charging process can be obtained by using a preset method based on the actual charging voltage of each single cell in the battery pack during the charging process and the charging capacity of the battery pack. When determining the full capacity difference between each single cell and the highest fully charged single cell in the fully charged state, not only the target charging voltage of each single cell in the fully charged state is taken into account, but also the characteristic relationship between voltage and capacity during the charging process is taken into account. Compared with the prior art that only considers the voltage difference or capacity difference at the end of full charge, the full capacity difference determined in the fully charged state can be made more reasonable.

[0109] The total charging capacity of the battery pack is represented by Cap2_dch when it is fully charged, and the final total charging capacity during the charging process is represented by Cap2_dch_latest. The charging capacity difference between the total charging capacity of the battery pack when it is fully charged and the final total charging capacity during the charging process is the difference between Cap2_dch and Cap2_dch_latest, and 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.

[0110] S103, determining the total capacity of each single battery from the empty state to the full state according to each empty capacity difference, each full capacity difference and the total capacity of the battery pack.

[0111] The total capacity of the battery pack refers to the cumulative total capacity of the battery pack from an empty state to a full state, and can be represented by Q0, for example.

[0112] Specifically, the total capacity of each single cell from the empty state to the full state can be determined using a preset method according to the empty capacity difference between each single cell and the lowest empty single cell, the full capacity difference between each single cell and the highest full single cell, and the total capacity of the battery pack. The total capacity of each single cell can be represented by Array_Q, for example.

[0113] Optionally, it can be seen that when determining the total capacity of each single cell from the empty state to the full state, the difference in empty capacity between each single cell and the lowest empty single cell in the empty state, and the difference in full capacity between each single cell and the highest full single cell in the full state are taken into account. This takes into account the difference in total capacity between each single cell when full and the difference in total capacity between each single cell when empty, which can make the total capacity of each single cell more reasonable and avoid treating the total capacity of each single cell as the same as in the prior art, resulting in unexpected balance.

[0114] S104: Determine the current total capacity of each single battery in a fully charged state according to the empty capacity differences and the total capacity of the battery pack.

[0115] Optionally, the current total capacity of each single cell in the full state can be determined according to the empty capacity difference between each single cell and the lowest empty single cell and the total capacity of the battery pack. The current total capacity of each single cell can be represented by Array_QP, for example, and can be obtained by the following formula (VI).

[0116] Optionally, when determining the current total capacity of each single cell in a fully charged state, the difference in empty capacity between each single cell and the lowest empty single cell in an empty state is taken into account, so that the current total capacity of each single cell obtained can be more reasonable.

[0117] S105 , determining the balancing amount of each single cell according to the total capacity of each single cell, the current total capacity of each single cell and each full capacity difference, and performing charge and discharge balancing on each single cell according to the balancing amount of each single cell.

[0118] The total capacity of a single cell refers to the total capacity of the single cell from an empty state to a fully charged state, and the current total capacity of a single cell refers to the total capacity of the single cell when the battery pack is in a fully charged state.

[0119] Specifically, the balancing amount of each single cell can be determined using a preset method based on the total capacity of each single cell from an empty state to a full state, the current total capacity of each single cell when the battery pack is in a full state, and the difference in full capacity between each single cell and the highest fully charged single cell in a full state.

[0120] In this embodiment, when determining the empty capacity difference between each single cell and the lowest empty single cell in the empty state, it is determined according to the target discharge voltage of each single cell in the empty state, the first mapping relationship between the voltage and the capacity during the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the empty state and the final total discharge capacity during the discharge process. In this process, the correlation between the voltage characteristics and the capacity during the battery discharge process is taken into account, so that each empty capacity difference obtained can be more reasonable; at the same time, when determining the full capacity difference between each single cell and the highest full single cell in the full state, the correlation between the voltage characteristics and the capacity during the charging process is taken into account, so that each full capacity difference obtained can also be more reasonable. Reasonable; when determining the total capacity of each single cell from the empty state to the full state, the difference in the total capacity between the single cells when full and the difference in the total capacity between the single cells when empty are taken into account, so that the total capacity of each single cell obtained is more reasonable; when determining the current total capacity of each single cell in the full state, the difference in the empty capacity between each single cell in the empty state and the lowest empty single cell is taken into account, so that the current total capacity of each single cell obtained is more reasonable; therefore, balancing based on the balancing amount of each single cell obtained according to the total capacity of each single cell, the current total capacity of each single cell and the difference in the full capacity mentioned above can make the balancing effect better and improve the service life of the battery pack.

[0121] Optionally, in the above S101, determining the empty capacity difference between each single cell and the lowest-emptied single cell in the empty state according to the target discharge voltage of each single cell in the empty state, the first mapping relationship between the voltage and the capacity in the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the empty state and the last total discharge capacity in the discharge process may include:

[0122] Optionally, the actual discharge voltage before the target discharge voltage is corrected can be determined according to the target discharge voltage, and then the discharge capacity corresponding to the actual discharge voltage can be determined according to the first mapping relationship between voltage and capacity during the discharge process, and the discharge capacity is used as the first target capacity corresponding to the target discharge voltage. And the sum of the first target capacity and the discharge capacity difference is used as the emptying capacity difference Array1_dvmin_Cap between the single cell and the emptying minimum single cell. Among them, the discharge capacity difference can be represented by dCap1_dch. The emptying capacity difference can be specifically obtained by the following formula (I).

[0123] Optionally, in the above S102, determining the full capacity difference between each single cell and the highest-charged single cell in the full state according to the target charging voltage of each single cell in the full state, the second mapping relationship between the voltage and the capacity in the charging process, and the charging capacity difference between the total charging capacity of the battery pack in the full state and the final total charging capacity in the charging process may include:

[0124] Optionally, the actual charging voltage before the target charging voltage is corrected can be determined according to the target charging voltage, and then the charging capacity corresponding to the actual charging voltage can be determined according to the second mapping relationship between voltage and capacity during the charging process, and the charging capacity is used as the second target capacity corresponding to the target charging voltage, and the sum of the second target capacity and the charging capacity difference dCap2_dch is used as the full capacity difference Array2_dVmax_Cap. The full capacity difference can be specifically obtained by the following formula (II).

[0125] Figure 2 A flowchart of determining a mapping relationship is provided in an embodiment of the present application, such as Figure 2 As shown, the first mapping relationship between voltage and capacity during the discharge process can be determined by the following steps:

[0126] S201. During the discharge process of the battery pack, obtain each first total discharge capacity of the battery pack and its corresponding first minimum single cell voltage at intervals of a preset capacity change, and when the battery pack is in an empty state, obtain the total discharge capacity of the battery pack and its corresponding minimum single cell voltage.

[0127] Exemplarily, the preset capacity change amount may be, for example, 0.1Ah, that is, when the total discharge capacity of the battery pack changes by 0.1Ah, the first total discharge capacity after the change of 0.1Ah and the first minimum cell voltage corresponding to the first total discharge capacity are obtained. Specifically, if the battery pack contains 5 cells, such as cell A, cell B, cell C and cell D, if the first total discharge capacity of the battery pack changes from 9A.h to 8.9Ah, the cell voltage of cell A among the 5 cells is the lowest, then the cell voltage of cell A is used as the first minimum cell voltage corresponding to 8.9Ah. At the same time, the total discharge capacity corresponding to the last minimum cell voltage can also be obtained, for example, it can be represented by Cap1_dch_latest, and the total discharge capacity corresponding to the last first minimum cell voltage is also the last total discharge capacity in the discharge process in the aforementioned S101.

[0128] Optionally, when the battery pack is in an empty state, the total discharge capacity of the battery pack and its corresponding minimum single cell voltage are obtained.

[0129] S202: Determine a first mapping relationship between voltage and capacity during a discharge process according to 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.

[0130] Exemplarily, a 20-dimensional array Array1_minV may be set. During the discharge process, the first total discharge capacity of the battery pack and the first minimum single cell voltage corresponding to the first total discharge capacity may be obtained once every preset capacity change. Each time the condition that the total discharge capacity of the battery pack changes by a preset capacity change is triggered, the entire array is shifted to the right by one grid, and the new first minimum single cell voltage is filled in the first element of the array until the data at the 20th bit is replaced by the 19th bit data. And the first total discharge capacity when the condition that the total discharge capacity changes by a preset capacity change is triggered for the last time is recorded as Cap1_dch_latest.

[0131] Optionally, each first total discharge capacity and the total discharge capacity of the battery pack in an empty state can be used as the ordinate, and the first minimum single cell voltage corresponding to each first total discharge capacity and the minimum single cell voltage in an empty state can be used as the abscissa, so that a first mapping relationship between voltage and capacity during the discharge process can be obtained.

[0132] In this embodiment, according to the first mapping relationship between voltage and capacity during the discharge process, the correlation relationship between the voltage feature and the capacity can be obtained.

[0133] Optionally, after determining the first mapping relationship between voltage and capacity during the discharge process, the difference in discharge capacity between each single cell and the single cell with the lowest discharge capacity can also be obtained by the following formula (I).

[0134] Specifically, the array Array1_minV can be used as the horizontal coordinate, and the index number Index_Array_minV=[0,1,2,3…19] corresponding to each first lowest single cell voltage in the array can be used as the vertical coordinate. The empty capacity difference Array1_dVmin_Cap between each single cell and the empty lowest single cell can be obtained through formula (1).

[0135] Array1_dVmin_Cap=0.1×LookUpTable(Array1_minV,Index_Array_minV,Array1_CellV ′ )+dCap1_dch formula (I)

[0136] Among them, LookUpTable is a table lookup function, which uses linear interpolation method to calculate the empty capacity difference. If it exceeds the boundary value, the boundary value is taken.

[0137] Figure 3 A schematic diagram of another process for determining a mapping relationship provided in an embodiment of the present application, such as Figure 3 As shown, the second mapping relationship between voltage and capacity during the charging process can be determined by the following steps:

[0138] S301. During the charging process of the battery pack, obtain each second total charging capacity of the battery pack and its corresponding second highest single cell voltage at intervals of a preset capacity change, and when the battery pack is in a fully charged state, obtain the total charging capacity of the battery pack and its corresponding highest single cell voltage.

[0139] Exemplarily, the preset capacity change amount may be, for example, 0.1Ah. Specifically, a 20-dimensional array Array2_maxV may be set, that is, when the total charging capacity of the battery pack changes by 0.1Ah, the second total charging capacity after the change of 0.1Ah and the second highest single cell voltage corresponding to the second total charging capacity are obtained. Each time the condition that the total charging capacity of the battery pack changes by 0.1Ah is triggered, the entire array is shifted one grid to the right, and the new second highest single cell voltage is filled in the first element of the array until the data at the 20th bit is replaced by the 19th bit data. And the second total charging capacity of the battery pack when the condition that the total charging capacity changes by the preset capacity change amount is triggered for the last time is recorded as Cap2_dch_latest.

[0140] S302: Determine a second mapping relationship between voltage and capacity during the charging process according to 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.

[0141] Optionally, each second total charging capacity and the total charging capacity of the battery pack in a fully charged state can be used as the vertical coordinate, and the second highest single cell voltage corresponding to each second total charging capacity and the highest single cell voltage in a fully charged state can be used as the horizontal coordinate, so that a second mapping relationship between voltage and capacity during the charging process can be obtained.

[0142] Optionally, after determining the second mapping relationship between voltage and capacity during the charging process, the full capacity difference between each single cell and the most fully charged single cell can also be obtained by the following formula (II).

[0143] Optionally, the array Array2_maxV can be used as the horizontal coordinate, and the index number Index_Array_maxV=[0,1,2,3…19] corresponding to each highest single cell voltage in the array can be used as the vertical coordinate. The full capacity difference Array2_dVmax_Cap between each single cell and the fullest single cell can be obtained by formula (II).

[0144] Array2_dVmax_Cap=0.1×LookUpTable(Array2_maxV,Index_Array_maxV,Array2_CellV′)+dCap2_dch Formula (IV)

[0145] Among them, Array2_CellV′ is the target charging voltage of each single cell, LookUpTable is a table lookup function, and the full capacity difference is calculated using a linear interpolation method. If it exceeds the boundary value, the boundary value is taken.

[0146] Figure 4 A schematic diagram of a process for determining a target discharge voltage provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, the above target discharge voltage is obtained by correcting the actual discharge voltage of the single battery in the empty state, and may include:

[0147] S401, determining the actual discharge voltage of a single cell in an empty state, a first voltage change of a single cell under a preset condition, and a second voltage change of the lowest empty single cell.

[0148] Optionally, in the empty state, the actual discharge voltage Array1_CellV of each single cell may be measured.

[0149] Optionally, the preset condition means that when the empty state is met, the current of the battery pack is set to 0A. After a preset period of time, for example, 1 second, the voltage of each single cell will have an upward change, and the first voltage change Array1_dv of each single cell after the preset period of time is measured. This is to reduce the impact of the internal resistance difference of each single cell on the calculation result, wherein the second voltage change of the lowest discharged single cell can be represented by Array1_dv[Index_MinV], for example, where Index_MinV is the number of the lowest discharged single cell.

[0150] S402: Calculate a first voltage variation difference between the first voltage variation and the second voltage variation.

[0151] Specifically, the first voltage variation difference is the first voltage variation Array1_dv of the single cell minus the second voltage variation Array1_dv[Index_MinV] of the lowest discharged single cell.

[0152] S403: taking the difference between the actual discharge voltage of the single cell and the first voltage variation difference as the target discharge voltage of the single cell.

[0153] Specifically, the target discharge voltage of each single cell can be obtained by the following formula (III).

[0154] Array1_CellV′=Array1_CellV-Array1_dv+Array1_dv[Index_MinV] formula (3)

[0155] In this embodiment, by correcting the actual discharge voltage of the single battery when it is in the empty state, the influence of the internal resistance of each single battery on the equalization calculation can be eliminated.

[0156] Figure 5 A schematic diagram of a process for determining a target charging voltage provided in an embodiment of the present application is shown in FIG. Figure 5 As shown, the above target charging voltage is obtained by correcting the actual charging voltage of the single battery when it is fully charged, and may include:

[0157] S501, determining the actual charging voltage of a single cell when it is fully charged, the third voltage variation of the single cell under a preset condition, and the fourth voltage variation of the highest fully charged single cell.

[0158] Optionally, in the fully charged state, the actual charging voltage Array2_CellV of each single battery can be measured.

[0159] Optionally, when the full charge state is met, the current of the battery pack is set to 0A. After a preset period of time, for example, 1 second, the cell voltage of each single cell will have a downward change. Then, the third voltage change Array2_dv of each single cell after the preset period of time is measured. This is to reduce the impact of the internal resistance difference of each single cell on the calculation result. Among them, the fourth voltage change of the most fully charged single cell can be represented by Array2_dv[Index_MaxV], for example, where the number of the most fully charged single cell is Index_MaxV.

[0160] S502: Calculate a second voltage change difference between the third voltage change and the fourth voltage change.

[0161] Specifically, the second voltage variation difference is the third voltage variation Array2_dv of the single cell minus the fourth voltage variation Array2_dv[Index_MinV] of the fully charged highest single cell.

[0162] S503: taking the sum of the actual single cell voltage of the single cell and the difference between the second voltage variation as the target charging voltage of the single cell.

[0163] Optionally, the target charging voltage of each single cell can be obtained by the following formula (IV).

[0164] Array2_CellV′=Array2_CellV-Array2_dv+Array2_dv[Index_MaxV] Formula (IV)

[0165] Optionally, the last total discharge capacity during the discharge process is the last first total discharge capacity of the battery pack obtained at intervals of a preset capacity change.

[0166] Optionally, during the charging process, the final total charging capacity is the last second total charging capacity of the battery pack obtained at intervals of a preset capacity change.

[0167] Optionally, the total capacity of each single cell is the sum of the total capacity of the battery pack, the difference in full capacity of each single cell, and the difference in empty capacity of each single cell.

[0168] Specifically, the total capacity of each single battery from an empty state to a full state can be obtained by the following formula (V).

[0169] Array_Q=Q0+Array1_dVmin_Cap+Array2_dVmax_CapFormula (V)

[0170] Among them, Q0 is the total capacity of the battery pack, Array2_dVmax_Cap is the difference in full capacity of each single battery, and Array1_dVmin_Cap is the difference in empty capacity of each single battery.

[0171] Optionally, the current total capacity of each single cell is the sum of the total capacity of the battery pack and the difference between the discharged capacities of each single cell.

[0172] Specifically, the current total capacity of each single battery can be obtained by the following formula (VI).

[0173] Array_QP=Q0+Array1_dVmin_Cap Formula (VI)

[0174] Among them, Q0 is the total capacity of the battery pack, and Array1_dVmin_Cap is the difference in discharge capacity of each single battery.

[0175] Figure 6 A flowchart of another battery balancing method provided in an embodiment of the present application is shown in FIG. Figure 6 As shown, in the above S105, according to the total capacity of each single cell, the current total capacity of each single cell and the difference of each full capacity, the balancing amount of each single cell is determined, and the charge and discharge balancing of each single cell is performed according to the balancing amount of each single cell, which may include:

[0176] S601 : Determine a minimum total capacity from the total capacities of the single cells and determine a minimum current total capacity from the current total capacities of the single cells.

[0177] Among them, the minimum total capacity can be used, for example, Q min To represent the minimum current total capacity, for example, QP can be used min To express.

[0178] S602: Calculate the capacity difference between the minimum total capacity and the minimum current total capacity.

[0179] Specifically, the minimum total capacity minus the minimum current total capacity.

[0180] S603: The difference between the capacity difference and the full capacity difference corresponding to the single cell is used as the balancing amount of the single cell.

[0181] The balancing amount of the single battery can be represented by Bal_CaP, for example.

[0182] Specifically, the balancing amount of each single cell can be obtained by the following formula (VII).

[0183] Array_Bal_CaP=Q min -QP min -Array2_dVmax_Cap formula (VII)

[0184] Optionally, if the calculated balanced amount of the single cell is less than zero, it means that the single cell needs to be charged. In this embodiment, only the discharge balance situation is considered, so the single cell does not need to start balanced discharge.

[0185] Optionally, the theoretical balancing amount is calculated by the above formula (VII), but in actual balancing, due to the different internal resistances of the single cells, the voltages of the single cells will also vary to a certain extent. In order to reduce the balancing error, the following conditions should be followed in actual balancing.

[0186] First, when the single cell corresponding to the lowest single cell voltage and the single cell corresponding to the highest single cell voltage are the same single cell, it means that the single cell is the single cell with the smallest total capacity. The battery pack has reached the initial balanced state, and generally there is no need to start the balance.

[0187] Second, when in the empty state, if the single cell corresponding to the lowest single cell voltage and the single cell corresponding to the lowest capacity are the same single cell, the number of the single cell is recorded as IndexMinVQ. In the full state, the current voltage Array_CellV1 of each single cell is obtained. If Array_CellV1(i)<Array_CellV1(IndexMinVQ), where i is the number of each single cell, it means that the single cell voltage of the single cell is low enough and there is no need to start balancing for the time being. The balancing amount of the single cell is set to 0.

[0188] For example, if the single cell Cell3 has the lowest voltage and the lowest capacity when it is empty, when it is fully charged, the current voltage of the single cell Cell1 and the current voltage of the single cell Cell4 are lower than the current voltage of Cell3, then Cell1 and Cell4 do not need to start balanced discharge.

[0189] Third, when in the fully charged state, the single cell corresponding to the highest single cell voltage and the single cell corresponding to the lowest capacity are the same single cell, then the single cell is numbered as IndexMaxVQ. When in the empty state, the current voltage Array_CellV2 of each single cell is obtained. If Array_CellV2(i)>Array_CellV2(IndexMaxVQ), it means that the single cell voltage of the single cell is high enough, and balancing does not need to be turned on for the time being. The balancing amount of the single cell is set to 0.

[0190] For example, if in the fully charged state, the single cell voltage of single cell Cell2 is the highest and the single cell with the lowest capacity, and in the empty state, if the current voltage of Cell4 is higher than the current voltage of Cell2, then Cell4 does not need to start balanced discharge.

[0191] Fourth, combining the second and third, it can be obtained that when the battery is fully charged and discharged, and the battery with the lowest capacity is also the battery, the battery pack does not need to be in a balancing state.

[0192] Optionally, based on the above-mentioned balancing of each single cell, further expansion can be performed. Specifically, the balancing amount Array_Bal_CaP1 of each single cell can be determined according to the preset proportional coefficient KdCapMinMax, the total capacity of each single cell, and the full capacity difference between each single cell and the highest fully charged single cell, which can be specifically calculated by the following formula (VIII). The proportional coefficient can indicate the ratio between the full capacity difference Array2_dVmax_Cap corresponding to the highest single cell voltage when the minimum single cell capacity is full and the empty capacity difference Array1_dVmin_Cap corresponding to the lowest fully charged single cell in the empty state.

[0193] Array_Bal_CaP1=max(Array2_dVmax_Cap)-

[0194] Array2_dVmax_Cap+KdCapMinMax*(Array_Q-Q min ) Formula (VIII)

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

[0196] Figure 7 A diagram of a battery balancing effect provided in an embodiment of the present application. Figure 7 The equalization diagram corresponding to the maximum capacity equalization in the embodiment of the present application is an effect diagram of single cell equalization using the method provided in the embodiment of the present application. Figure 7 It can be seen that the balancing amount of each single cell is lower and the balancing efficiency is faster.

[0197] The discharge end equalization method is equalized according to the following formula (IX).

[0198] Array_Bal_CaP2=Array_Bal_CaP1 Formula (IX)

[0199] The charging terminal balancing method is based on the following formula (10) for balancing.

[0200] Array_Bal_CaP2=max(Array2_dVmax_Cap)-Array2_dVmax_Cap Formula (X)

[0201] Figure 8 A schematic diagram of a battery balancing method provided in an embodiment of the present application is shown in FIG. Figure 8 As shown, the device comprises:

[0202] The discharge determination module 701 is used to determine the empty capacity difference between each single cell and the lowest empty single cell in the empty state according to the target discharge voltage of each single cell in the empty state, the first mapping relationship between voltage and capacity in the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the empty state and the last total discharge capacity in the discharge process; wherein the target discharge voltage is obtained by correcting the actual discharge voltage of the single cell in the empty state, and the lowest empty single cell is the single cell with the lowest actual discharge voltage in the empty state;

[0203] The charging determination module 702 is used to determine the full capacity difference between each of the single cells and the highest-full single cell in the full state according to the target charging voltage of each of the single cells in the full state, the second mapping relationship between the voltage and the capacity in the charging process, and the charging capacity difference between the total charging capacity of the battery pack in the full state and the final total charging capacity in the charging process; wherein the target charging voltage is obtained by correcting the actual charging voltage of the single cells in the full state, and the highest-full single cell is the single cell with the highest actual charging voltage in the full state;

[0204] The capacity determination module 703 is used to determine the total capacity of each of the single cells from the empty state to the full state according to each of the empty capacity differences, each of the full capacity differences and the total capacity of the battery pack, and to determine the current total capacity of each of the single cells in the full state according to each of the empty capacity differences and the total capacity of the battery pack;

[0205] The balancing module 704 is used to determine the balancing amount of each single cell according to the total capacity of each single cell, the current total capacity of each single cell and the full capacity difference, and balance the charge and discharge of each single cell according to the balancing amount of each single cell.

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

[0207] Determining, according to the target discharge voltage, an actual discharge voltage before correction of the target discharge voltage;

[0208] Determining a discharge capacity corresponding to the actual discharge voltage according to a first mapping relationship between the voltage and the capacity during the discharge process, and using the discharge capacity as a first target capacity corresponding to the target discharge voltage;

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

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

[0211] Determining, according to the target charging voltage, an actual charging voltage before correction of the target charging voltage;

[0212] Determine, according to a second mapping relationship between voltage and capacity during the charging process, a charging capacity corresponding to the actual charging voltage, and use the charging capacity as a second target capacity corresponding to the target charging voltage;

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

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

[0215] During the discharge process of the battery pack, obtaining each first total discharge capacity of the battery pack and its corresponding first minimum single cell voltage at intervals of a preset capacity change, and obtaining the total discharge capacity of the battery pack and its corresponding minimum single cell voltage when the battery pack is in an empty state;

[0216] Determining a first mapping relationship between the voltage and the capacity during the discharge process according to 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;

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

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

[0219] A second mapping relationship between voltage and capacity during the charging process is determined according to 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.

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

[0221] Determine the actual discharge voltage of the single cell when it is in an empty state, the first voltage change of the single cell under a preset condition, and the second voltage change of the lowest empty single cell;

[0222] Calculating a first voltage change 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 first voltage variation difference is used as the target discharge voltage of the single cell.

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

[0225] Determine 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 highest single cell when it is fully charged;

[0226] Calculating a second voltage change difference between the third voltage change and the fourth voltage change;

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

[0228] Optionally, the last total discharge capacity in the discharge process is the last first total discharge capacity of the battery pack obtained by the interval preset capacity change;

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

[0230] Optionally, the total capacity of each of the single cells is the sum of the total capacity of the battery pack, the difference between the full capacities of each of the single cells, and the difference between the empty capacities of each of the single cells;

[0231] The current total capacity of each single cell is the sum of the total capacity of the battery pack and the difference between the discharged capacities of each single cell.

[0232] Optionally, the balancing module 704 is specifically configured to:

[0233] Determining a minimum total capacity from the total capacities of the single cells and determining a minimum current total capacity from the current total capacities of the single cells;

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

[0235] The difference between the capacity difference and the full capacity difference corresponding to the single cell is used as the balancing amount of the single cell.

[0236] Fig. 9 This is a structural block diagram of an electronic device 800 provided in an embodiment of the present application. The electronic device may be, for example, a battery balancing device as described in the above embodiment. Fig. 9 As shown, 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 communicates with the memory 802 through the bus 803. When the machine-readable instructions are executed by the processor 801, the method steps in the above method embodiment are performed.

[0238] The embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the method steps in the above-mentioned battery balancing processing method embodiment are executed.

[0239] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the system and device described above can refer to the corresponding process in the method embodiment, and will not be repeated in this application. In the several embodiments provided in this application, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0240] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, RandomAccess Memory), disk or optical disk and other media that can store program code.

[0241] The above are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be covered by the protection scope of the present application.

Claims

1. A battery balancing method, characterized in that: For performing charge and discharge balancing on each single cell in a battery pack, the method comprises: Determine the empty capacity difference between each single cell and the lowest empty single cell in the empty state according to the target discharge voltage of each single cell in the empty state, the first mapping relationship between voltage and capacity in the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the empty state and the last total discharge capacity in the discharge process; wherein the target discharge voltage is obtained by correcting the actual discharge voltage of the single cell in the empty state, and the lowest empty single cell is the single cell with the lowest actual discharge voltage in the empty state; According to the target charging voltage of each of the single cells in the full state, the second mapping relationship between the voltage and the capacity during the charging process, and the charging capacity difference between the total charging capacity of the battery pack in the full state and the final total charging capacity during the charging process, the full capacity difference between each of the single cells and the highest-full single cell in the full state is determined; wherein the target charging voltage is obtained by correcting the actual charging voltage of the single cells in the full state, and the highest-full single cell is the single cell with the highest actual charging voltage in the full state; Determine the total capacity of each of the single cells from the empty state to the full state according to each of the empty capacity differences, each of the full capacity differences and the total capacity of the battery pack; Determining the current total capacity of each of the single cells when in a fully charged state according to each of the empty capacity differences and the total capacity of the battery pack; The balancing amount of each single cell is determined according to the total capacity of each single cell, the current total capacity of each single cell and the full capacity difference, and the charge and discharge balancing of each single cell is performed according to the balancing amount of each single cell.

2. The battery equalization processing method according to claim 1, characterized in that: The method of determining the empty capacity difference between each single cell and the lowest empty single cell in the empty state according to the target discharge voltage of each single cell in the empty state, the first mapping relationship between the voltage and the capacity in the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the empty state and the last total discharge capacity in the discharge process, comprises: Determining, according to the target discharge voltage, an actual discharge voltage before correction of the target discharge voltage; Determining a discharge capacity corresponding to the actual discharge voltage according to a first mapping relationship between the voltage and the capacity during the discharge process, and using the discharge capacity as a first target capacity corresponding to the target discharge voltage; The sum of the first target capacity and the difference between the discharge capacity is used as the discharge capacity difference; The method of determining the full capacity difference between each of the single cells and the highest-charged single cell in the full state according to the target charging voltage of each of the single cells in the full state, the second mapping relationship between the voltage and the capacity in the charging process, and the charging capacity difference between the total charging capacity of the battery pack in the full state and the final total charging capacity in the charging process, comprises: Determining, according to the target charging voltage, an actual charging voltage before correction of the target charging voltage; Determine, according to a second mapping relationship between voltage and capacity during the charging process, a charging capacity corresponding to the actual charging voltage, and use the charging capacity as a second target capacity corresponding to the target charging voltage; The sum of the second target capacity and the charge capacity difference is used as the full charge capacity difference.

3. The battery equalization processing method according to claim 1, characterized in that: The first mapping relationship between voltage and capacity during the discharge process is determined by the following steps: During the discharge process of the battery pack, obtaining each first total discharge capacity of the battery pack and its corresponding first minimum single cell voltage at intervals of a preset capacity change, and obtaining the total discharge capacity of the battery pack and its corresponding minimum single cell voltage when the battery pack is in an empty state; Determining a first mapping relationship between the voltage and the capacity during the discharge process according to 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; The second mapping relationship between voltage and capacity during the charging process is determined by the following steps: During the charging process of the battery pack, the second total charging capacity of the battery pack and the corresponding second highest single cell voltage are obtained at intervals of a preset capacity change; when the battery pack is in a fully charged state, the total charging capacity of the battery pack and the corresponding highest single cell voltage are obtained; A second mapping relationship between voltage and capacity during the charging process is determined according to 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.

4. The battery equalization processing method according to claim 3, characterized in that: The target discharge voltage is obtained by correcting the actual discharge voltage of the single battery when it is in an empty state, and includes: Determine the actual discharge voltage of the single cell when it is in an empty state, the first voltage change of the single cell under a preset condition, and the second voltage change of the lowest empty single cell; Calculating a first voltage change difference between the first voltage change and the second voltage change; Using the difference between the actual single cell voltage of the single cell and the first voltage variation difference as the target discharge voltage of the single cell; The target charging voltage is obtained by correcting the actual charging voltage of the single battery when it is in a fully charged state, and includes: Determine 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 highest single cell when it is fully charged; Calculating a second voltage change difference between the third voltage change and the fourth voltage change; The sum of the actual single cell voltage of the single cell and the difference between the second voltage change amount is used as the target charging voltage of the single cell.

5. The battery equalization processing method according to claim 3, characterized in that: The last total discharge capacity in the discharge process is the last first total discharge capacity of the battery pack obtained by the interval preset capacity change; The final total charging capacity during the charging process is the last second total charging capacity of the battery pack obtained by the interval preset capacity change.

6. The battery equalization processing method according to claim 1, characterized in that: The total capacity of each of the single cells is the sum of the total capacity of the battery pack, the difference between the full capacity of each of the single cells, and the difference between the empty capacity of each of the single cells; The current total capacity of each single cell is the sum of the total capacity of the battery pack and the difference between the discharged capacities of each single cell.

7. The battery equalization processing method according to claim 1, characterized in that: Determining the balancing amount of each of the single cells according to the total capacity of each of the single cells, the current total capacity of each of the single cells, and the full capacity difference, includes: Determining a minimum total capacity from the total capacities of the single cells and determining a minimum current total capacity from the current total capacities of the single cells; Calculating a capacity difference between the minimum total capacity and the minimum current total capacity; The difference between the capacity difference and the full capacity difference corresponding to the single cell is used as the balancing amount of the single cell.

8. A battery equalization processing device, characterized in that: include: a discharge determination module, for determining, in the empty state, the empty capacity difference between each single cell and the lowest empty single cell according to the target discharge voltage of each single cell in the empty state, the first mapping relationship between voltage and capacity in the discharge process, and the discharge capacity difference between the total discharge capacity of the battery pack in the empty state and the last total discharge capacity in the discharge process; wherein the target discharge voltage is obtained by correcting the actual discharge voltage of the single cell in the empty state, and the lowest empty single cell is the single cell with the lowest actual discharge voltage in the empty state; A charging determination module, for determining the full capacity difference between each of the single cells and the highest-full single cell in the full state according to the target charging voltage of each of the single cells in the full state, the second mapping relationship between the voltage and the capacity in the charging process, and the charging capacity difference between the total charging capacity of the battery pack in the full state and the last total charging capacity in the charging process; wherein the target charging voltage is obtained by correcting the actual charging voltage of the single cells in the full state, and the highest-full single cell is the single cell with the highest actual charging voltage in the full state; a capacity determination module, for determining the total capacity of each of the single cells from an empty state to a full state according to each of the empty capacity differences, each of the full capacity differences and the total capacity of the battery pack, and for determining the current total capacity of each of the single cells in a full state according to each of the empty capacity differences and the total capacity of the battery pack; The balancing module is used to determine the balancing amount of each single cell according to the total capacity of each single cell, the current total capacity of each single cell and the full capacity difference, and to balance the charge and discharge of each single cell according to the balancing amount of each single cell.

9. An electronic device, characterized in that: The invention comprises a memory and a processor, wherein the memory stores a computer program executable by the processor, and the processor implements the steps of the battery balancing processing method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the battery balancing method according to any one of claims 1 to 7 are executed.

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