Cell balance adjustment device and method

Abstract

To provide a cell balance adjustment device and a method, of a battery module, enhancing a speed of cell balancing, and reducing balance adjustment errors.SOLUTION: A method includes: acquiring a first cell alone minimum voltage value and a first cell alone maximum voltage value when a battery module to be balance-adjusted is fully charged most recently; determining a first charge power amount within a corresponding first period of a first target cell in the battery module in response to the battery module executing a first charging operation; and on the basis of the first charge power amount, updating a balancing power amount of the first target cell. The first target cell has a voltage value of the first cell alone minimum voltage value or more. A corresponding first period of the first target cell is an elapsed time from a time when a voltage value of the first target cell reaches the first cell alone minimum voltage value for the first time to when the first charging operation of the battery module finishes.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present application relates to the field of battery management technology, and more particularly to a cell balancing apparatus and method. [Background technology]

[0002] Typically, a battery module is composed of multiple cells connected in series. As a battery module is used, the differences between the cells in the battery module gradually increase, resulting in a decrease in the consistency between the cells. The shortboard effect of a battery module causes variations between the cells, which can lead to problems such as a rapid deterioration in power, a shortened lifespan, and an increase in internal resistance during use of the battery module. As a result, the battery's characteristics cannot be fully utilized, and the available power of the battery is reduced. Therefore, implementing effective balance management for battery modules is extremely important, as it is beneficial for improving the consistency between the cells in the battery module, reducing the loss of available power, and extending the lifespan of the battery module. Summary of the Invention [Problem to be solved by the invention]

[0003] In related prior art balancing technologies, balancing is initiated when the voltage difference between the largest cell having the largest voltage value and the smallest cell having the smallest voltage value in a battery module exceeds a voltage difference threshold, mainly when the battery module is fully charged or in a resting state. After balancing is initiated, balancing is performed on the battery module using the voltage difference between the largest and smallest cells as the balancing amount. This conventional method of determining whether to start balancing based on the instantaneous voltage difference has drawbacks such as slow balancing speed and incorrect balancing.

[0004] The embodiments of the present application provide a cell balancing apparatus and method, which can improve the speed of cell balancing and reduce misbalance. [Means for solving the problem]

[0005] In a first aspect, an embodiment of the present application provides a cell balancing apparatus. The cell balancing apparatus includes processing means configured to execute a first operation. The first operation includes acquiring a first cell minimum voltage value and a first cell maximum voltage value during a most recent full charge of a battery module having a plurality of cells to be balanced, determining a first amount of charge energy for a first period corresponding to a first target cell in the battery module in response to the battery module performing a first charging operation, and updating the balancing energy of the first target cell based on the first amount of charge energy. The first target cell is a cell whose voltage value is equal to or greater than the first cell minimum voltage value when the battery module performs the first charging operation, and the first period corresponding to the first target cell is the time elapsed from the point in time when the voltage value of the first target cell first reaches the first cell minimum voltage value to the end of the first charging operation of the battery module.

[0006] By updating the balance power amount of the cells to be balanced based on the charge power amount of the cells to be balanced in the battery module, the above method can determine the more accurate balance power amount of the cells to be balanced, and reduce erroneous balance adjustments when performing balance adjustments based on the balance power amount. Furthermore, by determining the balance power amount of the cells to be balanced in the charging state and the stationary state of the battery module, balance adjustments are not limited to being performed only when the battery module is fully charged and in the stationary state and the maximum cell voltage difference satisfies certain conditions, which extends the time required for balance adjustment and further improves the speed of balance adjustments.

[0007] In one or more embodiments of the present application, the conditions for terminating the first charging operation include at least one of: the electrical connection between the battery module and the charging device is cut off; the battery module reaches a charging termination SOC; and the minimum cell voltage value in the first charging operation of the battery module is equal to or greater than the first minimum cell voltage value.

[0008] Here, the processing means controls the termination of the first charging operation based on the termination condition of the first charging operation so that the voltage value of the smallest cell in the first charging operation of the battery module does not exceed the first cell minimum voltage value. As a result, the cell whose voltage value is equal to or greater than the first cell minimum voltage value is set as the first target cell to be subjected to balance adjustment, thereby reducing erroneous balance adjustment.

[0009] In one or more embodiments of the present application, the processing means is configured to perform a second operation before performing the first operation, and the second operation includes determining whether the number of consecutive times that the charge termination SOC is less than or equal to the first SOC threshold is less than M times in the most recent N historical charging operations of the battery module, and performing the first operation in response to the consecutive number being less than M times, where M and N are positive integers and M is less than or equal to N.

[0010] Here, if the number of consecutive times that the charge termination SOC is equal to or less than the first SOC threshold in the historical charging operation of the battery module is less than M, it is determined that the situation in which the battery module was not charged to a specified SOC value in the charging state has not occurred multiple times in succession. When the battery module is charged to a high SOC, the balance power amount of the cells to be balance-adjusted in the battery module is calculated based on the first operation, thereby improving the calculation accuracy of the balance power amount, and performing balance adjustment processing on the cells in the battery module based on the determined balance power amount, thereby reducing erroneous balance adjustment.

[0011] In one or more embodiments of the present application, the processing means is configured to perform the first operation in response to the SOC of the battery module in the current charging operation exceeding a first SOC threshold when the consecutive number of times is equal to or greater than M times.

[0012] Here, if the SOC in the current charging operation of the battery module exceeds a first SOC threshold, it is determined that the SOC of the battery module in the current charging operation of the battery module has exceeded a specified SOC value. When the battery module is charged to a high SOC, the balance power amount of the cells to be subjected to balance adjustment in the battery module is calculated based on the first operation, thereby improving the calculation accuracy of the balance power amount, and performing balance adjustment processing on the cells in the battery module based on the determined balance power amount, thereby reducing erroneous balance adjustment.

[0013] In one or more embodiments of the present application, the processing means is configured to perform a third operation when the consecutive number of times is equal to or greater than M, the SOC of the battery module in the current charging operation is equal to or less than a first SOC threshold, and the battery module is in a stationary state. The third operation includes: obtaining an open-circuit voltage value of a smallest cell in the battery module and open-circuit voltage values ​​of remaining cells; calculating a balance capacity of the remaining cells based on the SOC-OCV function, the open-circuit voltage value of the smallest cell, and the open-circuit voltage values ​​of the remaining cells; and obtaining an updated balance capacity of the remaining cells, where the smallest cell is the cell in the battery module with the smallest voltage value, and the remaining cells are cells other than the smallest cell in the battery module.

[0014] Here, if the number of consecutive times during the historical charging operation of the battery module where the charge termination SOC is equal to or less than the first SOC threshold is less than M, and the SOC during the charging operation of the battery module is equal to or less than the first SOC threshold, it is determined that a situation where the battery module was not charged to a specified SOC value occurred multiple times consecutively during the charging process. When the battery module is in a stationary state, it is possible to identify cells requiring balancing and obtain the balancing capacity of the cells requiring balancing based on the SOC-OCV function. By performing balancing on the cells requiring balancing in the battery module based on the determined balancing capacity, it is possible to improve cell consistency when the SOC of the battery module is low, further reducing the adverse effects of cell variation on the battery module and improving the quality of the battery module.

[0015] In one or more embodiments of the present application, the processing means is configured to perform a fourth operation when the consecutive number of times is M or more, the SOC of the battery module in the current charging operation is less than or equal to a first SOC threshold, the battery module is in a charging state, and a fluctuation value of the charge rate of the battery module is less than a fluctuation threshold. The fourth operation includes: acquiring a second-cell maximum voltage value before the current charging operation of the battery module; determining a second amount of charging energy for a second target cell in the battery module during a second period corresponding to the battery module performing the second charging operation; and updating the balance amount of the second target cell based on the second amount of charging energy, wherein the second target cell is a cell whose voltage value is greater than or equal to the second-cell maximum voltage value when the battery module performs the second charging operation, and the second period corresponding to the second target cell is the time elapsed from the time when the voltage value of the second target cell first reaches the second-cell maximum voltage value during the second charging operation of the battery module to the end of the second charging operation of the battery module.

[0016] Here, if the number of consecutive times that the charge termination SOC is equal to or less than the first SOC threshold in the historical charging operation of the battery module is less than M, and the SOC in the charging operation of the battery module is equal to or less than the first SOC threshold, it is determined that a situation in which the battery module was not charged to a specified SOC value occurred multiple times consecutively during the charging process. In this case, by updating the balance power amount of the cell to be balance adjusted based on the charge power amount of the cell to be balance adjusted in the battery module while the battery module is in a charging state, it is possible to determine a more accurate balance power amount of the cell to be balance adjusted. By performing balance adjustment based on the balance power amount, it is possible to reduce incorrect balance adjustment and improve consistency when the SOC of the cell in the battery module is low, thereby improving the quality of the battery module.

[0017] In one or more embodiments of the present application, the conditions for terminating the second charging operation include at least one of: the electrical connection between the battery module and the charging device is disconnected; and the voltage value of the smallest cell in the second charging operation of the battery module is equal to or greater than the maximum voltage value of the second cell alone.

[0018] In one or more embodiments of the present application, the cell balancing device includes a plurality of balancing means, the number of which corresponds to the number of cells in the battery module, the balancing means including resistors and switches connected in series, the balancing means being installed in the processing means or the balancing means being electrically connected between the cells in the battery module and the processing means, and the processing means being configured to perform a fifth operation, the fifth operation including performing a balancing operation on each of the cells needing balancing in the battery module when the battery module is in a target state based on the balancing power amount or balancing capacity of the cells needing balancing in the battery module in response to the cells needing balancing in the battery module satisfying a balancing operation condition, the cells needing balancing including a first target cell, the remaining cells in the battery module, or a second target cell in the battery module, the target state including at least one of a charging state, a discharging state, and a resting state, and the balancing operation including controlling a switch in the balancing means corresponding to the cell needing balancing to be conductive and consuming power of the cell needing balancing through a resistor in the balancing means.

[0019] Here, when the battery module is in a charging state, a discharging state, or a resting state, the processing means determines that the cells satisfy the balancing operation condition, and further controls the switches to be conductive, causing the cells to perform a balancing operation by discharging, thereby improving the consistency of the cells in the battery module, improving the quality of the battery module, and enabling the balancing operation to be performed even when the battery module is in various states.

[0020] In one or more embodiments of the present application, the fifth operation includes updating the remaining balance power or balance capacity of the cell requiring balancing based on the balancing current and the balancing period when performing the balancing operation on the cell requiring balancing.

[0021] Here, when performing a balance adjustment process on cells in a battery module, the remaining balance energy or remaining balance capacity of the cells is periodically calculated and updated, and when the remaining balance energy or remaining balance capacity becomes 0, the balance adjustment operation is terminated, thereby improving the effectiveness of the balance adjustment process.

[0022] In one or more embodiments of the present application, the balancing operation conditions include at least one of: a temperature value of the cell requiring balancing being less than a first temperature threshold; a temperature value of a resistor in the balancing means corresponding to the cell requiring balancing being less than a second temperature threshold; a voltage value of the cell requiring balancing being greater than a voltage threshold; and a remaining balancing energy or remaining balancing capacity of the cell requiring balancing being greater than zero.

[0023] Here, balancing of overheated cells is avoided, balancing using overheated resistors is avoided, the cell voltage after balancing is prevented from being too low, and balancing can be terminated immediately when the remaining balancing energy or remaining balancing capacity of the cell becomes 0, thereby reducing incorrect balancing of cells and improving the effectiveness of balancing of cells.

[0024] In a second aspect, an embodiment of the present application provides a cell balancing method, which includes: acquiring a first cell minimum voltage value and a first cell maximum voltage value during a most recent full charge of a battery module having a plurality of cells to be balanced; determining a first amount of charging energy for a first target cell in the battery module during a first period in response to the battery module performing a first charging operation; and updating the balancing energy of the first target cell based on the first amount of charging energy, where the first target cell is a cell whose voltage value is equal to or greater than the first cell minimum voltage value during the first charging operation of the battery module, and the first period corresponding to the first target cell is the time elapsed from the point in time when the voltage value of the first target cell reaches the first cell minimum voltage value for the first time during the first charging operation of the battery module to the end of the first charging operation of the battery module.

[0025] By updating the balance power amount of the cells to be balanced based on the charge power amount of the cells to be balanced in the battery module, the above method can determine the more accurate balance power amount of the cells to be balanced, and reduce erroneous balance adjustments when performing balance adjustments based on the balance power amount. Furthermore, by determining the balance power amount of the cells to be balanced in the charging state and the stationary state of the battery module, balance adjustments are not limited to being performed only when the battery module is fully charged and in the stationary state and the maximum cell voltage difference satisfies certain conditions, which extends the time required for balance adjustment and further improves the speed of balance adjustments.

[0026] In one or more embodiments of the present application, before acquiring the first cell individual minimum voltage value and the first cell individual maximum voltage value at the most recent full charge of the battery module to be balance adjusted, the cell balancing method includes determining whether the number of consecutive times in the most recent N historical charging operations of the battery module that the charge end SOC is equal to or less than the first SOC threshold is less than M. Acquiring the first cell individual minimum voltage value and the first cell individual maximum voltage value at the most recent full charge of the battery module to be balance adjusted includes acquiring the first cell individual minimum voltage value and the first cell individual maximum voltage value at the most recent full charge of the battery module to be balance adjusted in response to the consecutive number being less than M, where M and N are positive integers and M is less than or equal to N.

[0027] Here, if the number of consecutive times that the charge termination SOC is equal to or less than the first SOC threshold in the historical charging operation of the battery module is less than M, it is determined that the situation in which the battery module was not charged to a specified SOC value in the charging state has not occurred multiple times in succession. When the battery module is charged to a high SOC, the balance power amount of the cells to be balance-adjusted in the battery module is calculated based on the first operation, thereby improving the calculation accuracy of the balance power amount, and performing balance adjustment processing on the cells in the battery module based on the determined balance power amount, thereby reducing erroneous balance adjustment.

[0028] In one or more embodiments of the present application, acquiring the minimum voltage value and the maximum voltage value of the first cell alone at the most recent full charge of the battery module to be subject to balance adjustment includes acquiring the minimum voltage value and the maximum voltage value of the first cell alone at the most recent full charge of the battery module to be subject to balance adjustment in response to the SOC in the current charging operation of the battery module exceeding the first SOC threshold value when the number of consecutive charges is M or more.

[0029] When the SOC during the charging operation of the battery module exceeds a first SOC threshold, it is determined that the SOC of the battery module has exceeded a specified SOC value. When the battery module is charged to a high SOC, the balance power amount of the cells to be subjected to balance adjustment in the battery module is calculated based on the first operation, thereby improving the calculation accuracy of the balance power amount, and performing balance adjustment processing on the cells in the battery module based on the determined balance power amount, thereby reducing erroneous balance adjustment.

[0030] In one or more embodiments of the present application, a cell balancing method includes: obtaining an open-circuit voltage value of a smallest cell in a battery module and an open-circuit voltage value of a remaining cell in the battery module when the consecutive number of times is M or more, the SOC of the battery module in the current charging operation is less than or equal to a first SOC threshold, and the battery module is in a stationary state; calculating a balancing capacity of the remaining cells based on the SOC-OCV function, the open-circuit voltage value of the smallest cell, and the open-circuit voltage values ​​of the remaining cells, and obtaining an updated balancing capacity of the remaining cells, where the smallest cell is the cell in the battery module with the smallest voltage value, and the remaining cells are cells other than the smallest cell in the battery module.

[0031] Here, if the number of consecutive times during the historical charging operation of the battery module where the charge termination SOC is equal to or less than the first SOC threshold is less than M, and the SOC during the charging operation of the battery module is equal to or less than the first SOC threshold, it is determined that a situation where the battery module was not charged to a specified SOC value occurred multiple times consecutively during the charging process. When the battery module is in a stationary state, it is possible to identify cells requiring balancing and obtain the balancing capacity of the cells requiring balancing based on the SOC-OCV function. By performing balancing on the cells requiring balancing in the battery module based on the determined balancing capacity, it is possible to improve cell consistency when the SOC of the battery module is low, further reducing the adverse effects of cell variation on the battery module and improving the quality of the battery module.

[0032] In one or more embodiments of the present application, a cell balancing method includes: acquiring a second cell individual maximum voltage value before a current charging operation of the battery module in accordance with the fact that the number of consecutive times is M or more, the SOC of the battery module in the current charging operation is less than or equal to a first SOC threshold, the battery module is in a charging state, and a fluctuation value of the charging rate of the battery module is less than a fluctuation threshold; determining a second charging energy amount for a second target cell in the battery module in accordance with the battery module performing a second charging operation; and updating a balancing energy amount of the second target cell based on the second charging energy amount, wherein the second target cell is a cell whose voltage value is greater than or equal to the second cell individual maximum voltage value when the battery module performs the second charging operation, and the corresponding second period of the second target cell is the time elapsed from the time when the voltage value of the second target cell first reaches the second cell individual maximum voltage value when the battery module performs the second charging operation, to the time when the second charging operation of the battery module is completed.

[0033] Here, if the number of consecutive times that the charge termination SOC is equal to or less than the first SOC threshold in the historical charging operation of the battery module is less than M, and the SOC in the charging operation of the battery module is equal to or less than the first SOC threshold, it is determined that a situation in which the battery module was not charged to a specified SOC value occurred multiple times consecutively during the charging process. In this case, by updating the balance power amount of the cell to be balance adjusted based on the charge power amount of the cell to be balance adjusted in the battery module while the battery module is in a charging state, it is possible to determine a more accurate balance power amount of the cell to be balance adjusted. By performing balance adjustment based on the balance power amount, it is possible to reduce incorrect balance adjustment and improve consistency when the SOC of the cell in the battery module is low, thereby improving the quality of the battery module.

[0034] In one or more embodiments of the present application, a cell balancing method includes, in response to a cell requiring balancing in a battery module satisfying a balancing operation condition, performing a balancing operation on each of the cells requiring balancing in the battery module based on a balancing power amount or a balancing capacity of the cell requiring balancing when the battery module is in a target state, the cells requiring balancing including a first target cell, the remaining cells in the battery module, or a second target cell in the battery module, and the target state including at least one of a charging state, a discharging state, and a resting state. The balancing operation includes controlling a switch in a balancing means corresponding to the cell requiring balancing to be conductive, and consuming power of the cell requiring balancing through a resistor in the balancing means.

[0035] Here, when the battery module is in a charging state, a discharging state or a resting state, the processing means determines that the cells satisfy the balancing operation conditions and further performs balancing operation on the cells, thereby improving the consistency of the cells in the battery module, improving the quality of the battery module, and enabling balancing operation to be performed even when the battery module is in various states.

[0036] In one or more embodiments of the present application, the cell balancing method includes, for each cell requiring balancing, updating a remaining balancing energy or a balancing capacity of the cell requiring balancing after performing a balancing operation on the cell requiring balancing based on a balancing current and a balancing period when performing the balancing operation on the cell requiring balancing.

[0037] Here, when performing a balance adjustment process on cells in a battery module, the remaining balance energy or remaining balance capacity of the cells is periodically calculated and updated, and when the remaining balance energy or remaining balance capacity becomes 0, the balance adjustment operation is terminated, thereby improving the effectiveness of the balance adjustment process.

[0038] In one or more embodiments of the present application, the balancing operation conditions include at least one of: a temperature value of the cell requiring balancing being less than a first temperature threshold; a temperature value of a resistor in the balancing means corresponding to the cell requiring balancing being less than a second temperature threshold; a voltage value of the cell requiring balancing being greater than a voltage threshold; and a remaining balancing energy or remaining balancing capacity of the cell requiring balancing being greater than zero.

[0039] Here, balancing of overheated cells is avoided, balancing using overheated resistors is avoided, the cell voltage after balancing is prevented from being too low, and balancing can be terminated immediately when the remaining balancing energy or remaining balancing capacity of the cell becomes 0, thereby reducing incorrect balancing of cells and improving the effectiveness of balancing of cells. [Brief explanation of the drawings]

[0040] [Figure 1] FIG. 1 is a schematic diagram of the balancing time of the conventional cell balancing method provided in the embodiment of the present application. [Figure 2] FIG. 2 is a schematic diagram showing the change in voltage value of the cell in the battery module provided in the embodiment of the present application. [Figure 3] FIG. 3 is an enlarged schematic diagram of the period when balance adjustment starts in FIG. 2 provided in an embodiment of the present application. [Figure 4] FIG. 4 is a schematic diagram of a cell balancing device provided in one embodiment of the present application. [Figure 5] FIG. 5 is a schematic diagram showing the change in voltage value of the cell in the battery module provided in the embodiment of the present application. [Figure 6] FIG. 6 is an enlarged schematic diagram of the first period in FIG. 5 provided in the examples of the present application. [Figure 7] FIG. 7 is a schematic diagram of the change in voltage value of a cell in a battery module provided in one embodiment of the present application. [Figure 8]FIG. 8 is an enlarged schematic diagram of the second period in FIG. 7 provided in one embodiment of the present application. [Figure 9] FIG. 9 is a schematic diagram of a cell balancing device provided in another embodiment of the present application. [Figure 10] FIG. 10 is a flowchart of a cell balancing method provided in one embodiment of the present application. [Figure 11] FIG. 11 is a flowchart of a cell balancing method provided in another embodiment of the present application. [Figure 12] FIG. 12 is a flowchart of a cell balancing method provided in yet another embodiment of the present application. [Figure 13] FIG. 13 is a structural schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0041] The features and exemplary embodiments of each aspect of the present application will be described in detail below, and in order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be described in more detail below with reference to the drawings and specific embodiments. It should be understood that the examples of the present application are merely for the purpose of providing a better understanding of the present application, and the specific embodiments described herein are only for the purpose of interpreting the present application, and do not limit the present application.

[0042] It should be noted that in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply that such an actual relationship or order exists between those entities or operations.

[0043] Conventional cell balancing methods typically perform cell balancing based on instantaneous voltage differences when a battery module is in the fully charged or stationary state and all cell voltages are equal to or greater than a voltage threshold. This method typically initiates balancing when the voltage difference between the largest and smallest cells is equal to or greater than the voltage difference threshold, and stops balancing when the voltage difference is less than the voltage difference threshold. When a battery module is in the fully charged or stationary state, the voltage difference between the largest and smallest cells is equal to or greater than the voltage difference threshold for a very short period of time. This short balancing time prevents the battery module from balancing itself, resulting in significant variations in cell voltage. The largest cell voltage refers to the maximum voltage of any single cell in the battery module, and the smallest cell voltage refers to the minimum voltage of any single cell in the battery module.

[0044] Referring to FIG. 1, FIG. 1 is a schematic diagram of the balancing time of a conventional cell balancing method. As shown in FIG. 1, the blue curves represent the change in cell voltage value in a battery module, with each blue curve corresponding to one cell. The red curves represent the change in voltage difference between the largest and smallest cells, with the largest cell representing the cell with the largest voltage value in the battery module and the smallest cell representing the cell with the smallest voltage value in the battery module. For example, when all the voltage values ​​of the cells in a battery module are 3.4V or higher, a method of balancing the cells based on the instantaneous voltage difference is used, with the voltage difference threshold set to 40mV (millivolts). As shown in FIG. 1, the time indicated by the blue dashed line is the start time of balancing, i.e., cell balancing of the battery module is only performed during the time indicated by the blue dashed line. As can be seen, the balancing time is extremely short, only about 10 minutes.

[0045] Furthermore, when balancing a battery module using a conventional cell balancing method, there is a problem of misbalancing. Misbalancing refers to balancing a cell that does not require balancing. Because the initial voltage values ​​of the cells change even when the battery module is fully charged or discharged and in a stationary state, the determined minimum cell may not be accurate, and balancing may be performed on the actual minimum cell, resulting in misbalancing. Referring to Figures 2 and 3, Figures 2 and 3 are schematic diagrams of the voltage changes of two different cells in the same battery module. The blue and red curves represent the voltage changes of different cells. The cell indicated by the blue curve is the first cell, and the cell indicated by the red curve is the second cell. The time corresponding to the red dotted circle in Figure 2 is the start time of balancing, and Figure 3 is an enlarged view of the red dotted circle in Figure 2. Referring to Figure 2, the first cell indicated by the blue curve is the actual minimum cell in the battery module. Therefore, when balancing, balancing should not be performed on the first cell. However, referring to Figure 3, the voltage value indicated by the blue curve in the blue dashed box is greater than the voltage value indicated by the red curve. Therefore, when performing balance adjustment, the second cell indicated by the red curve is identified as the smallest cell, and therefore balance adjustment is performed on the first cell indicated by the blue curve. As can be seen from Figure 2, the first cell is the actual smallest cell, so balance adjustment should not be performed. Therefore, the balance adjustment process indicated by the blue dashed box in Figure 3 is a misbalance adjustment.

[0046] When imbalance adjustment occurs, problems such as an increased energy dissipation rate of the battery module and a decreased power utilization rate occur.

[0047] Therefore, the conventional cell balancing method has drawbacks such as short balancing time, slow balancing speed, and improper balancing, which increases the energy dissipation rate of the battery module and reduces the power utilization rate.

[0048] To solve the above problems, the present invention provides a cell balancing apparatus and method, which will be described below.

[0049] The cell balancing device provided in the embodiments of the present application is for performing cell balancing on a battery module. In practice, the cell balancing device can be used standalone or integrated into a battery management system (BMS). The cell balancing device provided in the embodiments of the present application employs a technical principle of first detecting variations in the cells in the battery module and then performing balancing based on the variations.

[0050] 4, which is a schematic diagram of a cell balancing apparatus provided in an embodiment of the present application. As shown in FIG. 4, the cell balancing apparatus 400 provided in this embodiment includes at least a processing unit 401, which may include, but is not limited to, a processor CPU, a microcontroller MCU, etc.

[0051] In this embodiment, the processing means 401 acquires the minimum voltage value and the maximum voltage value of the first cell unit when the battery module having a plurality of cells, which is the target of the balance adjustment, was fully charged most recently.

[0052] In this embodiment, the most recent full charge of the battery module refers to the full charge operation closest to the current charging operation of the battery module. For example, if the previous charging operation of the battery module is a full charge operation, the end of charging in the previous charging operation is considered to be the most recent full charge of the battery module. The minimum cell voltage value of the most recent full charge of the battery module is considered to be the first cell minimum voltage value, and the maximum cell voltage value of the most recent full charge of the battery module is considered to be the first cell maximum voltage value.

[0053] In one or more embodiments of the present application, the cell balancing device 400 includes a storage means and a communication means, and the storage means and the processing means 401 exchange data via the communication means. The storage means stores the voltage V1max of the largest cell and the voltage V1min of the smallest cell at the end of charging during a full charge operation of the battery module. When a new voltage V1max of the largest cell at the end of full charge and a new voltage V1min of the smallest cell at the end of full charge are acquired, the voltage V1max of the largest cell and the voltage V1min of the smallest cell at the end of full charge stored in the storage means are overwritten. In other words, the storage means stores only the voltage V1max of the largest cell and the voltage V1min of the smallest cell at the end of the most recent full charge of the battery module. Based on this, in one preferred embodiment, the processing means 401 reads the voltage V1max of the largest cell and the voltage V1min of the smallest cell stored in the storage means and sets the voltage V1max of the largest cell as the maximum voltage value of the first cell unit and the voltage V1min of the smallest cell as the minimum voltage value of the first cell unit.

[0054] In this embodiment, the battery module performs a first charging operation, and the voltage value of the individual cells in the battery module increases. The processing means 401 determines whether the voltage value of the individual cells in the battery module reaches a first individual cell minimum voltage value, and identifies the cell that has reached the first individual cell minimum voltage value as the first target cell. It is understood that due to voltage variations between individual cells, one or more cells in the battery module that have reached the first individual cell minimum voltage value at different times are the one or more first target cells.

[0055] In this embodiment, for each first target cell, when the battery module performs the first charging operation, the processing means 401 integrates the current flowing through the first target cell from the time when the voltage value of the first target cell reaches the first cell minimum voltage value, stops the integration until the first charging operation of the battery module ends, and sets the obtained integrated value as the first charging energy amount for the corresponding first target cell in the first period. The first period is the period from the time when the voltage value of the first target cell reaches the first cell minimum voltage value to the time when the first charging operation ends.

[0056] In one or more embodiments of the present application, when the battery module operation performs a first charging operation, the processing means 401 determines whether the first charging operation meets the following termination condition:

[0057] The electrical connection between the battery module and the charging device has been cut off. The charging device is for supplying electrical energy to the battery module, and examples of the charging device include, but are not limited to, a power adapter, a charging stand, etc. For example, the electrical connection between the battery module and the charging device can be cut off by turning off the charging switch, or by cutting the physical connection between the charging device and the battery module.

[0058] The battery module reaches the end-of-charge SOC. The end-of-charge SOC of the battery module can be set according to the actual situation or predicted based on the historical charging record of the battery module.

[0059] The minimum single cell voltage value when the battery module performs the first charging operation is equal to or greater than the first minimum single cell voltage value.

[0060] When it is determined that the battery module satisfies any of the above termination conditions, the integration is stopped by determining to terminate the first charging operation. In this way, by ensuring that the voltage value of the smallest cell when the battery module performs the first charging operation does not exceed the first single-cell minimum voltage value, a cell whose voltage value is equal to or greater than the first single-cell minimum voltage value is identified as the first target cell to be subjected to balance adjustment, thereby reducing misbalance adjustment.

[0061] In this embodiment, for each first target cell, the processing means 401 updates the balance energy of the first target cell based on the first charging energy amount of the first target cell in the corresponding first period.

[0062] In one preferred embodiment, for each first target cell, the first charging energy amount during the corresponding first period of the first target cell is set as the required energy amount to be consumed in the balance adjustment process of the first target cell, i.e., the balance energy amount of the first target cell, and the balance adjustment process is performed on the first target cell based on the determined balance capacity, thereby reducing misbalance and improving the consistency between cells.

[0063] As an example of the present application, please refer to FIGS. 5 and 6. FIG. 5 is a schematic diagram of the charging voltage of a cell in a battery module. FIG. 5 shows the voltage change curve for two consecutive cell charge / discharge cycles. FIG. 6 is an enlarged view of the area circled by the red dashed line in FIG. 5. In FIGS. 5 and 6, the horizontal axis represents time in 10 seconds, and the vertical axis represents voltage in volts. The blue and red curves show the voltage change curves for different cells, with the blue curve representing the largest cell and the red curve representing the smallest cell. For example, assume that the minimum voltage of the first cell during the most recent full charge of a battery module is 3.45V. As shown in FIG. 5, the largest cell reaches 3.45V first. After the largest cell reaches 3.45V, the smallest cell does not reach 3.45V, and the battery module continues charging. As charging continues, the voltage of the largest cell continues to increase. When the smallest cell is charged to 3.45V, charging of the battery module is terminated. The purpose of cell balancing is to match the voltage of the largest cell with the voltage of the smallest cell. To achieve cell balancing, the largest cell must release the charge energy accumulated during the first period. The first period is the period Δt from when the largest cell is charged to 3.45V to when the smallest cell is charged to 3.45V, i.e., the period indicated by the red dashed circle. The amount of energy charged into the largest cell during Δt is calculated using an integral calculation. For example, let V2i be the voltage of the largest cell in the battery module. The current flowing through the largest cell is integrated when the voltage V2i of the largest cell in the battery module first reaches 3.45V. The charging is terminated and the integration is stopped when the voltage of the smallest cell in the battery module first reaches 3.45V. The integral value obtained when the integration is stopped is defined as the first charge energy of the largest cell, and the first charge energy is defined as the amount of energy required for balancing the first cell when performing the balancing operation.

[0064] In the cell balancing device provided in the embodiment of the present application, the processing means 401 updates the balancing power amount of the cells to be balanced based on the charge power amount of the cells to be balanced in the battery module, thereby determining a more accurate balancing power amount of the cells to be balanced and reducing erroneous balancing when performing balancing based on the balancing power amount. Furthermore, by determining the balancing power amount of the cells to be balanced in the charging state and the resting state of the battery module, balancing is not limited to only being performed when the battery module is fully charged and in the resting state and the maximum cell voltage difference satisfies certain conditions, thereby extending the balancing time and further improving the balancing speed.

[0065] The method of updating the balance energy of the first target cell based on the first charge capacity of the first target cell described above is applied when the battery module is charged so that the SOC of the battery module exceeds a specified SOC value, i.e., a first SOC threshold, during the current charging operation.

[0066] In one or more embodiments of the present application, before the processing means 401 acquires the minimum voltage value and the maximum voltage value of the first cell alone at the most recent full charge of the battery module to be balanced, the processing means 401 determines whether the number of consecutive times that the charge termination SOC is equal to or less than the first SOC threshold is less than M times in the most recent N historical charging operations of the battery module.

[0067] Here, M and N are positive integers, M is less than or equal to N, and the values ​​of M and N can be set according to the actual situation. For example, the first SOC threshold is a value in the range of 80% to 100%.

[0068] In this embodiment, the most recent N historical charging operations of the battery module refer to the N historical charging operations that are consecutive in charging time and are most recent to the current charging operation of the battery module.

[0069] In one or more embodiments of the present application, the cell balancing device 400 further includes a counter for counting the number of consecutive times that the charge termination SOC of the battery module is equal to or less than the first SOC threshold during the most recent N historical charging operations of the battery module. The storage means stores a flag bit of the counter, which is divided into two flag bits: 1 and 0. 1 indicates that the charge termination SOC of the battery module is equal to or less than the first SOC threshold M consecutive times, and 0 indicates that the charge termination SOC of the battery module is equal to or less than the first SOC threshold M consecutive times. Each time the battery module terminates charging after performing a charging operation, it updates the flag bit of the counter based on whether the charge termination SOC of the battery module is equal to or less than the first SOC threshold M consecutive times. For example, M is 4. If the charge termination SOC of the battery module is equal to or less than the first SOC threshold during the initial charging operation, the flag bit of the counter is set to 0, and the flag bit 0 is stored in the storage means. If the charge termination SOC during the second charging operation of the battery module is equal to or lower than the first SOC threshold, the counter flag bit remains at 0. If the charge termination SOC during the third and fourth charging operations of the battery module is equal to or lower than the first SOC threshold, the counter flag bit is updated to 1 after the fourth charging operation of the battery module is terminated. Based on this, in one preferred embodiment, the processing means 401 directly obtains the counter flag bit from the storage means. If the flag bit is 0, it is determined that the number of consecutive times in which the charge termination SOC during the most recent N historical charging operations of the battery module has been equal to or lower than the first SOC threshold is less than M. If the flag bit is 1, it is determined that the number of consecutive times in which the charge termination SOC during the most recent N historical charging operations of the battery module has been equal to or lower than the first SOC threshold is M or more. In this way, the processing means 401 can quickly determine whether the consecutive number is less than M.

[0070] In this embodiment, if the processing means 401 determines that the number of consecutive charges is less than M, it determines that the number of times the battery module was not consecutively charged to the first SOC threshold in the previous N charging operations is less than M. The minimum and maximum voltage values ​​of the first cell alone during the most recent full charge of the battery module to be subjected to balance adjustment are acquired and recorded as the first charging operation in the next charging operation of the battery module. If the battery module is charged to exceed the first SOC threshold, it is determined that the SOC of the battery module has exceeded a specified SOC value. If the battery module is charged to a high SOC, the balancing power amount of the cells to be subjected to balance adjustment in the battery module is calculated based on the first operation, thereby improving the calculation accuracy of the balancing power amount. By performing balancing adjustment processing on the cells in the battery module based on the determined balancing power amount, it is possible to reduce incorrect balancing adjustment.

[0071] The processing means 401 is configured to perform other operations when the consecutive number of times is equal to or greater than M times, in order to adapt the battery module to different scenarios.

[0072] In one or more embodiments of the present application, when the processing means 401 determines that the consecutive number of times is equal to or greater than M, if the SOC of the battery module in the current charging operation is equal to or less than a first SOC threshold and the battery module is in a stationary state, obtains the open-circuit voltage value of the smallest cell and the open-circuit voltage values ​​of the remaining cells in the battery module.

[0073] In this embodiment, the smallest cell is the cell with the smallest voltage value in the battery module, and the remaining cells are the cells other than the smallest cell in the battery module. The open-circuit voltage value of a cell is also called the no-load voltage value, and refers to the voltage value of the cell when no current is flowing through it.

[0074] After obtaining the open circuit voltage value of the smallest cell and the open circuit voltage values ​​of the remaining cells in the battery module, the processing means 401 calculates the balance capacity of the remaining cells based on the SOC-OCV function, the open circuit voltage value of the smallest cell, and the open circuit voltage values ​​of the remaining cells, and obtains the updated balance capacity of the remaining cells.

[0075] In this embodiment, the processing means 401 determines whether the battery module is in a resting state by determining whether the resting time of the battery module exceeds a threshold, whether the voltage fluctuation is below a threshold, whether the current is below a threshold, etc. If it is determined that the battery module is in a resting state, the processing means 401 updates the balancing capacity of the remaining cells other than the smallest cell in the battery module based on the SOC-OCV function. Here, the SOC-OCV function represents the correspondence relationship between SOC and OCV, and the SOC-OCV function may be represented in the form of a curve, a functional relationship, a table, etc.

[0076] In one or more embodiments of the present application, when updating the balancing energy of the remaining cells other than the smallest cell in the battery module based on the SOC-OCV function, the processing means 401 determines a first SOC value corresponding to the open-circuit voltage value of the remaining cells and a second SOC value corresponding to the open-circuit voltage value of the smallest cell based on the SOC-OCV function, calculates a difference between the first SOC value and the second SOC value, and sets the difference value as the updated balancing capacity of the remaining cells.

[0077] For example, taking the SOC-OCV function as represented by an SOC-OCV table, the processing means 401 searches the SOC-OCV table to determine a first SOC value corresponding to the open-circuit voltage value of the remaining cells and a second SOC value corresponding to the open-circuit voltage value of the smallest cell, calculates a difference between the first SOC value and the second SOC value, and sets the difference value as the balance capacity of the remaining cells after updating.

[0078] If the charge termination SOC is equal to or less than the first SOC threshold M times or more consecutively during the historical charging operation of the battery module, and the SOC during the charging operation of the battery module is equal to or less than the first SOC threshold, it is determined that the battery module was not charged to the specified SOC value multiple times consecutively during the charging process. When the battery module is in a stationary state, the SOC-OCV function can be used to identify cells requiring balancing when the battery module is in a stationary state and to obtain the balancing capacity of the cells requiring balancing. By performing balancing on the cells requiring balancing in the battery module based on the determined balancing capacity, it is possible to improve cell consistency when the SOC of the battery module is low, further reducing the adverse effects on the battery module caused by cell mismatch and improving the quality of the battery module.

[0079] In one or more embodiments of the present application, if it is determined that the number of consecutive times that the charge termination SOC is equal to or less than the first SOC threshold is M or more in the most recent N historical charging operations of the battery module, the battery module may be in a charging state in addition to a resting state.

[0080] If the processing means 401 determines that the number of consecutive times in the most recent N historical charging operations of the battery module that the charging termination SOC is equal to or less than the first SOC threshold is M or more, and that the charging termination SOC in the current charging operation of the battery module is equal to or less than the first SOC threshold, and the battery module is in a charging state, the processing means 401 causes the battery module to perform a second charging operation.

[0081] When the battery module performs the second charging operation and the fluctuation or change rate of the charging rate is small, the processing means 401 first obtains the second cell individual minimum voltage value and the second cell individual maximum voltage value in the battery module before the battery module performs the second charging operation.

[0082] In a preferred embodiment, a small charge rate fluctuation or change rate refers to a charge rate fluctuation or change rate that does not exceed a change threshold. For example, the change threshold may be any value selected from the group consisting of 0.1%, 0.5%, 1%, 2%, 5%, 8%, and 10%, or any value in the range of 0.1% to 10%. The specific values ​​listed above are examples of change thresholds and should not be construed as limiting the small charge rate fluctuation or change in this specification. The purpose of limiting the charge rate fluctuation value of a battery module to less than the change threshold is to eliminate the effects of current fluctuations by balancing the cells when the battery module is charging stably, thereby improving the calculation accuracy of the balanced power.

[0083] In this embodiment, when the battery module performs a second charging operation and the voltage value of each cell in the battery module increases, the processing means 401 determines whether the voltage value of each cell reaches a second maximum voltage value of each cell, and identifies the cell that reaches the second maximum voltage value as the second target cell. Due to voltage variations between cells, one or more cells in the battery module that reach the second maximum voltage value at different times are understood to be the one or more first target cells. The second maximum voltage value of each cell refers to the maximum voltage value of each cell in the battery module before the battery module performs the second charging operation.

[0084] In this embodiment, for each second target cell, when the battery module performs the second charging operation, the processing means 401 integrates the current flowing through the second target cell from the time when the voltage value of the second target cell first reaches the second cell maximum voltage value, stops the integration until the second charging operation of the battery module ends, and sets the obtained integrated value as the second charging energy amount for the corresponding second target cell in the second period. The second period is the period from the time when the voltage value of the second target cell reaches the second cell maximum voltage value until the second charging operation ends.

[0085] In one or more embodiments of the present application, when the battery module performs the second charging operation, the processing means 401 determines whether the second charging operation meets the following termination condition:

[0086] The electrical connection between the battery module and the charging device is cut off. The charging device is used to supply electrical energy to the battery module, and includes, but is not limited to, a power adapter, a charging stand, etc.

[0087] When the battery module performs the second charging operation, the minimum cell voltage value is equal to or greater than the second maximum cell voltage value.

[0088] When it is determined that the battery module satisfies any of the above termination conditions, the second charging operation is terminated and the integration is stopped. In this way, by ensuring that the voltage value of the smallest cell when the battery module performs the second charging operation does not exceed the second single-cell maximum voltage value, a cell whose voltage value is equal to or greater than the second single-cell maximum voltage value is identified as the second target cell to be subjected to balance adjustment, thereby reducing misbalance adjustment.

[0089] In this embodiment, for each second target cell, the processing means 401 updates the balance energy of the second target cell based on the second charging energy of the second target cell in the corresponding second period.

[0090] In one or more embodiments of the present application, for each second target cell, the second charging energy amount in the corresponding second period of the second target cell is set as the required energy amount to be consumed in the balance adjustment process of the second target cell, i.e., the balance energy amount of the second target cell, and the balance adjustment process is performed on the second target cell based on the determined balance capacity, thereby reducing misbalance and improving the consistency between cells.

[0091] For example, see Figures 7 and 8. Figure 7 is a schematic diagram of the charging voltage of cells in a battery module. Figure 7 shows the voltage change curve for two consecutive cell charge / discharge cycles, and Figure 8 is an enlarged view of the red dashed circle in Figure 7. In Figures 7 and 8, the horizontal axis represents time in 10 seconds, and the vertical axis represents voltage in volts. The blue and red curves show the voltage change curves for different cells, with the blue curve representing the largest cell and the red curve representing the smallest cell. For example, assume that the minimum voltage of the first cell during the most recent full charge of a battery module is 3.312 V. As shown in Figure 7, the largest cell reaches 3.312 V first. After the largest cell reaches 3.312 V, the smallest cell does not reach 3.312 V, and the battery module continues charging. As charging continues, the voltage of the largest cell continues to increase, and when the smallest cell is charged to 3.312 V, charging of the battery module is terminated. The purpose of cell balancing is to match the voltage of the largest cell with the voltage of the smallest cell. To achieve cell balancing, the largest cell must release the charge energy accumulated during the first period. The first period is the period Δt from when the largest cell is charged to 3.312 V to when the smallest cell is charged to 3.312 V, i.e., the period indicated by the red dashed circle. The amount of energy charged to the largest cell during Δt is calculated using an integral calculation. For example, let V2i be the voltage of the largest cell in the battery module. The current flowing through the largest cell is integrated when the voltage V2i of the largest cell in the battery module first reaches 3.312 V. Charging is terminated and integration is stopped when the voltage of the smallest cell in the battery module first reaches 3.312 V. The integral value obtained when integration is stopped is the second charge energy of the largest cell, and this second charge energy is the updated balance energy of the largest cell.

[0092] In this way, if the number of consecutive times that the charge termination SOC is equal to or less than the first SOC threshold in the historical charging operation of the battery module is M or more and the SOC in the charging operation of the battery module is equal to or less than the first SOC threshold, it is determined that a situation in which the battery module was not charged to a specified SOC value occurred multiple times consecutively during the charging process. In this case, by updating the balance power amount of the cell to be subjected to balance adjustment based on the charge power amount of the cell to be subjected to balance adjustment in the battery module while the battery module is in a charging state, it is possible to determine a more accurate balance power amount of the cell to be subjected to balance adjustment. By performing balance adjustment based on the balance power amount, it is possible to reduce incorrect balance adjustment and improve consistency when the SOC of the cell in the battery module is low, thereby improving the quality of the battery module.

[0093] In one or more embodiments of the present application, during the most recent N charging operations of a battery module, the charging termination SOC has been below a first SOC threshold multiple times, and the number of times the charging termination SOC has been below the first SOC threshold has exceeded M consecutive times. During the current charging operation of the battery module, if the SOC of the battery module increases and exceeds the first SOC threshold, the processor performs a first operation to calculate the balancing power of the cells to be balanced in the battery module. Based on this, when the processing means 401 determines that the consecutive number of times is M or more, it detects whether the SOC of the battery module is below the first SOC threshold during the current charging operation of the battery module. If the SOC of the battery module exceeds the first SOC threshold during the current charging operation, it determines the balancing capacity of the first target cell in the battery module in the same manner as when the battery module performs the first charging operation. At the same time, it changes a flag bit of a counter from 1 to 0.

[0094] When the SOC during the charging operation of the battery module exceeds a first SOC threshold, it is determined that the SOC of the battery module has exceeded a specified SOC value. When the battery module is charged to a high SOC, the balanced power amount of the cells to be balanced in the battery module is calculated based on the first operation, thereby improving the calculation accuracy of the balanced power amount, and performing the balancing process on the cells in the battery module based on the determined balanced power amount, thereby reducing erroneous balancing.

[0095] In some embodiments, as shown in FIG. 9 , a cell balancing device 400 includes a plurality of balancing means 402, the number of which corresponds to the number of cells in a battery module, and the balancing means 402 includes resistors and switches connected in series, and the conduction / cutoff between the resistors and the cells can be controlled by controlling the conduction / cutoff of the switches.

[0096] In one preferred embodiment, the switch is a controlled switch, such as a MOS transistor.

[0097] In some embodiments of the present application, the balancing means 402 is located in the processing means 401 .

[0098] In another embodiment of the present application, the balancing means 402 is electrically connected between the cells in the battery module and the processing means 401, and FIG. 9 shows an example in which the balancing means 402 is electrically connected between the cells in the battery module and the processing means 401.

[0099] In this embodiment, the processing means 401 is configured as follows: For each cell in a battery module requiring balancing, if the cell satisfies the balancing operation conditions, the processing means 401 controls the switch in the balancing means corresponding to the cell requiring balancing to be conductive based on the balancing power or balancing capacity of the cell in the battery module requiring balancing, if the battery module is in a target state, and the resistance in the balancing means consumes the power of the cell requiring balancing, thereby achieving balancing for the cell requiring balancing. Here, the cell requiring balancing includes the first target cell, the remaining cells in the battery module, or the second target cell in the battery module. That is, when the battery module is in a different condition, the cell requiring balancing is the first target cell, the remaining cells in the battery module, or the second target cell in the battery module. The target state includes at least one of a charging state, a discharging state, and a resting state.

[0100] In this way, when the battery module is in a charging state, a discharging state, or a resting state, the processing means determines that the cells satisfy the balancing operation condition, and further controls the switches to be conductive, causing the cells to perform a balancing operation by discharging, thereby improving the consistency of the cells in the battery module, improving the quality of the battery module, and enabling the balancing operation to be performed even when the battery module is in various operating states.

[0101] In one or more embodiments of the present application, the balancing operation conditions may include at least one of the following:

[0102] The temperature value of the cell requiring balancing is less than a first temperature threshold, where the first temperature threshold can be set according to the actual situation. By setting this condition, balancing of overheated cells can be avoided.

[0103] The temperature value of the resistor in the balancing means corresponding to the cell requiring balancing is less than a second temperature threshold, where the second temperature threshold can be set according to the actual situation. By setting this condition, balancing using an overheated resistor can be avoided.

[0104] The voltage value of the cell that needs balancing exceeds a voltage threshold. Here, the voltage threshold may be the discharge end voltage or the minimum voltage that the cell momentarily drops to during high-power discharge. However, the voltage threshold can be set according to the actual situation. By setting this condition, it is possible to prevent the cell voltage from being too low after balancing.

[0105] The remaining balance energy of the cells that require balance adjustment exceeds 0. By setting this condition, it is possible to prevent balance adjustment of cells that do not require balance adjustment, and to reduce erroneous balance adjustment.

[0106] In this embodiment, for each cell requiring balancing, the processing means 401 determines whether the cell requires balancing meets the balancing operation conditions. If any of the conditions are not met, the processing means 401 determines that the cell requires balancing does not meet the balancing operation conditions, and does not perform balancing on the cell requiring balancing. If all of the conditions are met, the processing means 401 determines that the cell requires balancing meets the balancing operation conditions, and performs balancing on the cell requiring balancing by the balancing means 402 corresponding to the cell requiring balancing. This avoids balancing on overheated cells, avoids balancing using overheated resistors, and prevents cell voltages from being too low after balancing. It also immediately terminates balancing when the remaining balancing energy or remaining balancing capacity of a cell becomes zero, reducing incorrect cell balancing and improving the effectiveness of cell balancing.

[0107] In order to improve the success rate of balance adjustment, the processing means 401 is further configured as follows: before performing a balance adjustment operation on a cell requiring balance adjustment, it determines whether the balance adjustment means 402 corresponding to the cell requiring balance adjustment is available, and if it is determined that the balance adjustment means 402 is available, it performs the balance adjustment operation on the cell requiring balance adjustment.

[0108] In one or more embodiments of the present application, the balance adjustment means 402 periodically performs a balancing operation on the cells requiring balancing, i.e., performs one balancing operation per cycle and performs balancing operations over multiple cycles to consume all of the balancing energy or balancing capacity of the cells requiring balancing. Based on this, for each cell requiring balancing, in each balancing cycle, the processing means 401 updates the remaining balancing energy or remaining balancing capacity of the cells requiring balancing based on the balancing current and the balancing cycle in the balancing operation for the cells requiring balancing. When the balancing operation is performed on the cells requiring balancing, the balancing energy or balancing capacity of the cells requiring balancing gradually decreases. Meanwhile, the reduced balancing energy or balancing capacity in each balancing cycle is the product of the balancing current and the length of the balancing cycle, so the remaining balancing energy or remaining balancing capacity of the cells requiring balancing can be accurately updated based on the balancing current and the balancing cycle in the balancing operation. After updating the remaining balance energy or remaining balance capacity, if a cell requiring balance adjustment satisfies the balance adjustment operation conditions, the balance adjustment operation is continued for the cell requiring balance adjustment based on the updated remaining balance energy or remaining balance capacity in the next balance adjustment period until the remaining balance energy or remaining balance capacity of the cell requiring balance adjustment is updated to 0.

[0109] In this way, when performing a balance adjustment process on cells in a battery module, the remaining balance energy or remaining balance capacity of the cells is periodically calculated and updated, and when the remaining balance energy or remaining balance capacity becomes 0, the balance adjustment operation is terminated, thereby improving the effectiveness of the balance adjustment process.

[0110] Corresponding to the cell balancing device provided in the above embodiment, the present application provides a cell balancing method, and specific embodiments are described in the following examples.

[0111] Referring to FIG. 10, the cell balancing method provided in the embodiment of the present application includes the following steps S101 to S103.

[0112] S101: Obtain the minimum voltage value and the maximum voltage value of the first cell unit when the battery module having a plurality of cells is most recently fully charged, which is the target of the balance adjustment.

[0113] S102, determining a first charging energy amount of a first target cell in the battery module during a corresponding first period in response to the battery module performing a first charging operation.

[0114] S103: updating the balance energy of the first target cell based on the first charging energy amount;

[0115] Here, the first target cell is a cell whose voltage value is equal to or greater than the first cell minimum voltage value when the battery module performs the first charging operation, and the corresponding first period of the first target cell is the time elapsed from the point when the voltage value of the first target cell first reaches the first cell minimum voltage value when the battery module performs the first charging operation, until the first charging operation of the battery module is completed.

[0116] In the cell balancing method provided in the embodiments of the present application, by updating the balance power amount of the cell to be balanced based on the charge power amount of the cell to be balanced in the battery module, it is possible to determine a more accurate balance power amount of the cell to be balanced, and when performing balance adjustment based on the balance power amount, it is possible to reduce erroneous balance adjustment. Furthermore, by determining the balance power amount of the cell to be balanced in the charging state and the resting state of the battery module, it is not limited to performing balance adjustment only when the battery module is fully charged and in the resting state and the maximum cell voltage difference satisfies certain conditions, so the balance adjustment time is longer and the balance adjustment speed is further improved.

[0117] In one or more embodiments of the present application, the condition for terminating the first charging operation is: The electrical connection between the battery module and the charging device is cut off; The battery module reaches an end-of-charge SOC; a minimum cell voltage value in the first charging operation of the battery module being equal to or greater than the first minimum cell voltage value.

[0118] Here, the processing means controls the termination of the first charging operation based on the termination condition of the first charging operation so that the voltage value of the smallest cell in the first charging operation of the battery module does not exceed the first cell minimum voltage value. As a result, the cell whose voltage value is equal to or greater than the first cell minimum voltage value is set as the first target cell to be subjected to balance adjustment, thereby reducing erroneous balance adjustment.

[0119] In one or more embodiments of the present application, before acquiring a first cell minimum voltage value and a first cell maximum voltage value at the most recent full charge of a battery module to be subjected to balance adjustment, the cell balance adjustment method includes: determining whether the number of consecutive times that the charge termination SOC is equal to or less than the first SOC threshold is less than M times in the most recent N historical charging operations of the battery module; Acquiring the minimum voltage value and the maximum voltage value of the first cell alone when the battery module to be balanced was fully charged most recently is The processing means includes executing a first operation in response to the consecutive number of times being less than M; M and N are positive integers, and M is less than or equal to N.

[0120] Here, if the number of consecutive times that the charge termination SOC is equal to or less than the first SOC threshold in the historical charging operation of the battery module is less than M, it is determined that the situation in which the battery module was not charged to a specified SOC value in the charging state has not occurred multiple times in succession. When the battery module is charged to a high SOC, the balance power amount of the cells to be balance-adjusted in the battery module is calculated based on the first operation, thereby improving the calculation accuracy of the balance power amount, and performing balance adjustment processing on the cells in the battery module based on the determined balance power amount, thereby reducing erroneous balance adjustment.

[0121] In one or more embodiments of the present application, acquiring the minimum voltage value and the maximum voltage value of the first cell alone at the most recent full charge of the battery module to be subject to balance adjustment includes acquiring the minimum voltage value and the maximum voltage value of the first cell alone at the most recent full charge of the battery module to be subject to balance adjustment in response to the SOC in the current charging operation of the battery module exceeding the first SOC threshold value when the number of consecutive charges is M or more.

[0122] When the SOC during the charging operation of the battery module exceeds a first SOC threshold, it is determined that the SOC of the battery module has exceeded a specified SOC value. When the battery module is charged to a high SOC, the balance power amount of the cells to be subjected to balance adjustment in the battery module is calculated based on the first operation, thereby improving the calculation accuracy of the balance power amount, and performing balance adjustment processing on the cells in the battery module based on the determined balance power amount, thereby reducing erroneous balance adjustment.

[0123] In one or more embodiments of the present application, as shown in FIG. 11, the cell balancing method may further include the following steps S111 to S112.

[0124] S111: If the number of consecutive times is M or more, the SOC of the battery module in the current charging operation is less than or equal to the first SOC threshold, and the battery module is in a stationary state, the open-circuit voltage value of the smallest cell in the battery module and the open-circuit voltage values ​​of the remaining cells are obtained.

[0125] In step S112, the balance capacity of the remaining cells is calculated based on the SOC-OCV function, the open circuit voltage value of the minimum cell, and the open circuit voltage values ​​of the remaining cells, and the updated balance capacity of the remaining cells is obtained.

[0126] In this embodiment, the minimum cell is the cell with the minimum voltage value in the battery module, and the remaining cells are the cells in the battery module other than the minimum cell.

[0127] Here, if the number of consecutive times during the historical charging operation of the battery module where the charge termination SOC is equal to or less than the first SOC threshold is less than M, and the SOC during the charging operation of the battery module is equal to or less than the first SOC threshold, it is determined that a situation where the battery module was not charged to a specified SOC value occurred multiple times consecutively during the charging process. When the battery module is in a stationary state, it is possible to identify cells requiring balancing and obtain the balancing capacity of the cells requiring balancing based on the SOC-OCV function. By performing balancing on the cells requiring balancing in the battery module based on the determined balancing capacity, it is possible to improve cell consistency when the SOC of the battery module is low, further reducing the adverse effects of cell variation on the battery module and improving the quality of the battery module.

[0128] In one or more embodiments of the present application, as shown in FIG. 12, the cell balancing method may further include the following steps S121 to S123.

[0129] S121: When the battery module performs a second charging operation in accordance with the fact that the number of consecutive times is M or more, the SOC of the battery module in the current charging operation is equal to or less than the first SOC threshold, the battery module is in a charging state, and the fluctuation value of the charging rate of the battery module is less than the fluctuation threshold, the second cell maximum voltage value before the current charging operation of the battery module is obtained.

[0130] S122, determining a second charging energy amount for a second target cell in the battery module during a second period.

[0131] S123: updating the balance energy of the second target cell based on the second charging energy.

[0132] Here, the second target cell is a cell whose voltage value is equal to or greater than the second cell maximum voltage value when the battery module performs the second charging operation, and the corresponding second period of the second target cell is the time elapsed from the point when the voltage value of the second target cell first reaches the second cell maximum voltage value when the battery module performs the second charging operation, to the end of the second charging operation of the battery module.

[0133] Here, if the number of consecutive times that the charge termination SOC is equal to or less than the first SOC threshold in the historical charging operation of the battery module is less than M, and the SOC in the charging operation of the battery module is equal to or less than the first SOC threshold, it is determined that a situation in which the battery module was not charged to a specified SOC value occurred multiple times consecutively during the charging process. In this case, by updating the balance power amount of the cell to be balance adjusted based on the charge power amount of the cell to be balance adjusted in the battery module while the battery module is in a charging state, it is possible to determine a more accurate balance power amount of the cell to be balance adjusted. By performing balance adjustment based on the balance power amount, it is possible to reduce incorrect balance adjustment and improve consistency when the SOC of the cell in the battery module is low, thereby improving the quality of the battery module.

[0134] In one or more embodiments of the present application, a cell balancing method includes: performing a balancing operation on each of the cells requiring balancing in the battery module based on a balancing energy or a balancing capacity of the cells requiring balancing in the battery module in response to the cells requiring balancing satisfying a balancing operation condition when the battery module is in a target state; the cells requiring balancing include a first target cell, the remaining cells in the battery module, or a second target cell in the battery module; the target state includes at least one of a charging state, a discharging state, and a stationary state; The balancing operation includes controlling the switches in the balancing means corresponding to the cells requiring balancing to be conductive, and dissipating the power of the cells requiring balancing through resistors in the balancing means.

[0135] Here, when the battery module is in a charging state, a discharging state or a resting state, the processing means determines that the cells satisfy the balancing operation conditions and further performs balancing operation on the cells, thereby improving the consistency of the cells in the battery module, improving the quality of the battery module, and enabling balancing operation to be performed even when the battery module is in various states.

[0136] In one or more embodiments of the present application, a cell balancing method includes: For each cell requiring balance adjustment, after performing a balance adjustment operation on the cell requiring balance adjustment, updating the remaining balance energy or balance capacity of the cell requiring balance adjustment based on the balance current and balance period when performing the balance adjustment operation on the cell requiring balance adjustment.

[0137] Here, when performing a balance adjustment process on cells in a battery module, the remaining balance energy or remaining balance capacity of the cells is periodically calculated and updated, and when the remaining balance energy or remaining balance capacity becomes 0, the balance adjustment operation is terminated, thereby improving the effectiveness of the balance adjustment process.

[0138] In one or more embodiments of the present application, the balancing operating condition is: The temperature value of the cell requiring balancing is less than a first temperature threshold; and the temperature value of the resistor in the balancing means corresponding to the cell requiring balancing is less than the second temperature threshold; The voltage value of the cell that needs balancing exceeds a voltage threshold; The remaining balance power amount or remaining balance capacity of the cell requiring balance adjustment exceeds 0.

[0139] Here, balancing of overheated cells is avoided, balancing using overheated resistors is avoided, the cell voltage after balancing is prevented from being too low, and balancing can be terminated immediately when the remaining balancing energy or remaining balancing capacity of the cell becomes 0, thereby reducing incorrect balancing of cells and improving the effectiveness of balancing of cells.

[0140] FIG. 13 is a schematic diagram showing the hardware structure of an electronic device provided in an embodiment of the present application.

[0141] The electronic device 1300 may include a processor 1301 and a memory 1302 that stores computer program instructions.

[0142] In particular, the processor 1301 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present application.

[0143] Memory 1302 may include mass memory used for data and instructions. For example, memory 1302 may include, but is not limited to, a hard disk drive (HDD), a floppy disk drive, flash memory, an optical disk, a magneto-optical disk, magnetic tape, or a universal serial bus (USB) drive, or a combination of two or more thereof. In appropriate circumstances, memory 1302 includes removable or non-removable (or fixed) media. In appropriate circumstances, memory 1302 may be located internal or external to the integrated gateway disaster response device. In certain embodiments, memory 1302 is non-volatile solid-state memory. Memory 1302 may include read-only memory (ROM), random access memory (RAM), a magnetic disk storage media device, an optical storage media device, a flash memory device, an electrical, optical, or other physical / tangible memory storage device. Thus, memory 1302 generally includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, which, when executed (e.g., by one or more processors), can perform the operations described in any one of the cell balancing methods according to the above embodiments.

[0144] The processor 1301 reads and executes computer program instructions stored in the memory 1302 to implement any one of the cell balancing methods according to the above embodiments.

[0145] In one example, the electronic device 1300 may further include a communication interface 1303 and a bus 1310. Here, as shown in Figure 13, the processor 1301, the memory 1302, and the communication interface 1303 are connected by the bus 1310 and complete communication between them.

[0146] The communication interface 1303 is mainly used to realize communication between the modules, apparatuses, units and / or devices in the embodiment of the present application.

[0147] The bus 1310 may include hardware, software, or both, and may couple the components of the online data traffic charging device to one another. For example, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Extended Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin-in Count (LPC) bus, a memory bus, a MicroChannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Accessory (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or any other suitable bus, or a combination of two or more thereof. Under appropriate circumstances, the bus 1310 may include one or more buses. While embodiments herein are illustrated and described with particular buses, the present application contemplates any suitable bus or interconnect.

[0148] Furthermore, referring to the cell balancing method in the above embodiments, the embodiments of the present application can be realized by providing a computer storage medium having computer program instructions stored therein, which, when executed by a processor, realizes any one of the cell balancing methods in the above embodiments.

[0149] It should be noted that the present application is not limited to the specific configurations and processes described above and illustrated in the drawings. For the sake of simplicity, detailed descriptions of known methods are omitted herein. In the above embodiments, some specific steps are described and illustrated as examples. However, the method process of the present application is not limited to the specific steps described and illustrated, and those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of the present application.

[0150] The functional blocks illustrated in the above-described block diagrams can be implemented as hardware, software, firmware, or a combination thereof. When implemented as hardware, the hardware may be, for example, an electronic circuit, an application-specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, or the like. When implemented as software, the elements of this application are programs or code segments for performing the necessary tasks. The programs or code segments may be stored on a machine-readable medium or transmitted by a data signal carried on a carrier wave over a transmission medium or a communication link. The term "machine-readable medium" may include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memories, erasable ROMs (EROMs), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments may also be downloaded via a computer network such as the Internet or an intranet.

[0151] It should be noted that the exemplary embodiments described herein describe some methods or systems based on a sequence of steps or devices, but the present application is not limited to the order of the steps described above, i.e., steps may be performed according to the order described in the embodiments, or may be performed in a different order than in the embodiments, or multiple steps may be performed simultaneously.

[0152] The above describes various aspects of the present disclosure with reference to flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present disclosure. It should be understood that each block in the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, may be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, thereby generating an apparatus, such that the instructions, when executed by the processor of the computer or other programmable data processing apparatus, implement the functions / operations specified in one or more blocks in the flowcharts and / or block diagrams. Such a processor may be, but is not limited to, a general-purpose processor, a special-purpose processor, a special-purpose application processor, or a field-programmable logic circuit. It should be understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by dedicated hardware that performs the specified functions or operations, or by a combination of dedicated hardware and computer instructions.

[0153] The above is merely a specific embodiment of the present application, and those skilled in the art will understand that for the sake of convenience and brevity, the specific operating processes of the above-described systems, modules, and units can refer to the corresponding processes in the above-described method examples, but will not be described here.

Claims

1. A cell balancing device, processing means configured to perform a first operation; The first operation includes: acquiring a first cell minimum voltage value and a first cell maximum voltage value at the most recent full charge of a battery module having a plurality of cells to be subjected to balance adjustment; determining a first charging energy amount of a first target cell in the battery module during a corresponding first period in response to the battery module performing a first charging operation; updating a balance amount of power of the first target cell based on the first amount of charged power; the first target cell is a cell whose voltage value is equal to or greater than the first cell minimum voltage value when the battery module performs the first charging operation, the first period corresponding to the first target cell is the time elapsed from the time when the voltage value of the first target cell reaches the first cell minimum voltage value for the first time when the battery module performs the first charging operation to the time when the first charging operation of the battery module is completed; A cell balancing device comprising:

2. The condition for terminating the first charging operation is: The electrical connection between the battery module and the charging device is cut off; and the battery module reaches an end-of-charge SOC; a minimum cell voltage value in the first charging operation of the battery module is equal to or greater than the first minimum cell voltage value; at least one of:

2. The cell balancing device according to claim 1, wherein:

3. The processing means is configured to perform a second operation before performing the first operation, the second operation comprising: determining whether the number of consecutive times that the end-of-charge SOC is equal to or less than a first SOC threshold is less than M times in the most recent N history charging operations of the battery module; In response to the consecutive number of times being less than M, the processing means executes the first operation; M and N are positive integers, and M is less than or equal to N; 2. The cell balancing device according to claim 1, wherein:

4. the processing means is configured to execute the first operation when the consecutive number of times is equal to or greater than M times and when an SOC in the current charging operation of the battery module exceeds the first SOC threshold.

4. The cell balancing device according to claim 3, wherein:

5. the processing means is configured to execute a third operation in response to the fact that the consecutive number of times is equal to or greater than M, the SOC of the battery module in the current charging operation is equal to or less than the first SOC threshold, and the battery module is in a stationary state; The third operation is Obtaining an open circuit voltage value of a smallest cell and open circuit voltage values ​​of remaining cells in the battery module; calculating a balance capacity of the remaining cells based on an SOC-OCV function, an open circuit voltage value of the smallest cell, and an open circuit voltage value of the remaining cells, and obtaining an updated balance capacity of the remaining cells; the minimum cell is a cell with a minimum voltage value in the battery module, the remaining cells are cells other than the smallest cell in the battery module; 4. The cell balancing device according to claim 3, wherein:

6. the processing means is configured to execute a fourth operation in response to the fact that the consecutive number of times is equal to or greater than M, the SOC of the battery module in the current charging operation is equal to or less than the first SOC threshold, the battery module is in a charging state, and a fluctuation value of the charge rate of the battery module is less than a fluctuation threshold; The fourth operation is acquiring a second cell maximum voltage value of the battery module before the current charging operation; determining a second amount of charging energy of a second target cell in the battery module during a corresponding second period in response to the battery module performing a second charging operation; updating the balance energy amount of the second target cell based on the second charging energy amount; the second target cell is a cell whose voltage value is equal to or greater than the second single-cell maximum voltage value when the battery module performs the second charging operation, the second period corresponding to the second target cell is the time elapsed from the time when the voltage value of the second target cell reaches the second single-cell maximum voltage value for the first time when the battery module performs the second charging operation to the time when the second charging operation of the battery module is completed; 4. The cell balancing device according to claim 3, wherein:

7. The condition for terminating the second charging operation is: The electrical connection between the battery module and the charging device is cut off; and a voltage value of a minimum cell in the second charging operation of the battery module is equal to or greater than a second maximum cell voltage value; at least one of:

7. The cell balancing device according to claim 6, wherein:

8. A plurality of balancing means is provided, the number of the balancing means corresponds to the number of cells in the battery module, and the balancing means includes resistors and switches connected in series; the balancing means is installed on the processing means, or the balancing means is electrically connected between the cells in the battery module and the processing means; the processing means is configured to perform a fifth operation; The fifth operation is performing a balance adjustment operation on each of the cells requiring balance adjustment in the battery module based on a balanced energy amount or a balanced capacity of the cells requiring balance adjustment in the battery module when the battery module is in a target state in response to the cells requiring balance adjustment in the battery module satisfying a balance adjustment operation condition; the cells requiring balancing include the first target cell, the remaining cells in the battery module, or the second target cell in the battery module; the target state includes at least one of a charging state, a discharging state, and a stationary state; the balance adjustment operation includes controlling a switch in the balance adjustment means corresponding to the cell requiring balance adjustment to be conductive, and consuming power of the cell requiring balance adjustment through a resistor in the balance adjustment means. The cell balance adjustment device according to any one of claims 1 to 7.

9. The fifth operation is updating a remaining balanced energy amount or a balanced capacity of the cell requiring balance adjustment based on a balancing current and a balancing period when the balancing operation is performed on the cell requiring balance adjustment; 9. The cell balancing device according to claim 8, wherein:

10. The balance adjustment operation condition is: the temperature value of the cell requiring balancing is less than a first temperature threshold; the temperature value of the resistor in the balancing means corresponding to the cell requiring balancing is less than a second temperature threshold; The voltage value of the cell requiring balancing exceeds a voltage threshold; The remaining balance energy or remaining balance capacity of the cell requiring balance adjustment exceeds 0; at least one of:

10. The cell balancing device according to claim 9, wherein:

11. A cell balancing method, comprising: acquiring a first cell minimum voltage value and a first cell maximum voltage value at the most recent full charge of a battery module having a plurality of cells to be subjected to balance adjustment; determining a first charging energy amount of a first target cell in the battery module during a corresponding first period in response to the battery module performing a first charging operation; updating a balance amount of power of the first target cell based on the first amount of charged power; the first target cell is a cell whose voltage value is equal to or greater than the first cell minimum voltage value when the battery module performs the first charging operation, the first period corresponding to the first target cell is the time elapsed from the time when the voltage value of the first target cell reaches the first cell minimum voltage value for the first time when the battery module performs the first charging operation to the time when the first charging operation of the battery module is completed; A cell balancing method comprising:

12. determining whether or not the number of consecutive times in which a charge end SOC is equal to or less than a first SOC threshold is less than M times in the most recent N history charging operations of the battery module before obtaining the first cell individual minimum voltage value and the first cell individual maximum voltage value at the most recent full charge of the battery module to be subjected to the balance adjustment; The acquisition of the first cell minimum voltage value and the first cell maximum voltage value at the most recent full charge of the battery module to be subjected to the balance adjustment includes: acquiring the first cell minimum voltage value and the first cell maximum voltage value at the most recent full charge of the battery module to be subjected to the balance adjustment when the consecutive number of times is less than M times; M and N are positive integers, and M is less than or equal to N; The cell balance adjustment method according to claim 11 .

13. The acquisition of the first cell minimum voltage value and the first cell maximum voltage value at the most recent full charge of the battery module to be subjected to the balance adjustment includes: and acquiring the first cell minimum voltage value and the first cell maximum voltage value at the most recent full charge of the battery module to be subjected to the balance adjustment in response to the consecutive number of times being equal to or greater than M and the SOC of the battery module in the current charging operation exceeding the first SOC threshold. The cell balance adjustment method according to claim 12 .

14. acquiring an open-circuit voltage value of a smallest cell and open-circuit voltage values ​​of remaining cells in the battery module in response to the fact that the consecutive number of times is equal to or greater than M, the SOC of the battery module in the current charging operation is equal to or less than the first SOC threshold, and the battery module is in a stationary state; calculating a balance capacity of the remaining cells based on an SOC-OCV function, an open circuit voltage value of the smallest cell, and an open circuit voltage value of the remaining cells, and obtaining an updated balance capacity of the remaining cells; the minimum cell is a cell with a minimum voltage value in the battery module, the remaining cells are cells other than the smallest cell in the battery module; The cell balance adjustment method according to claim 12 .

15. acquiring a second cell maximum voltage value before the current charging operation of the battery module in response to the fact that the consecutive number of times is M or more, the SOC of the battery module in the current charging operation is equal to or less than the first SOC threshold, the battery module is in a charging state, and a fluctuation value of the charge rate of the battery module is less than a fluctuation threshold; determining a second amount of charging energy of a second target cell in the battery module during a corresponding second period in response to the battery module performing a second charging operation; updating the balance energy amount of the second target cell based on the second charging energy amount; the second target cell is a cell whose voltage value is equal to or greater than the second single-cell maximum voltage value when the battery module performs the second charging operation, the second period corresponding to the second target cell is the time elapsed from the time when the voltage value of the second target cell reaches the second single-cell maximum voltage value for the first time when the battery module performs the second charging operation to the time when the second charging operation of the battery module is completed; The cell balance adjustment method according to claim 12 .

16. performing a balance adjustment operation on each of the cells requiring balance adjustment in the battery module based on a balanced energy amount or a balanced capacity of the cells requiring balance adjustment in the battery module when the battery module is in a target state in response to the cells requiring balance adjustment in the battery module satisfying a balance adjustment operation condition; the cells requiring balancing include the first target cell, the remaining cells in the battery module, or the second target cell in the battery module; the target state includes at least one of a charging state, a discharging state, and a stationary state; the balance adjustment operation includes controlling a switch in a balance adjustment means corresponding to the cell requiring balance adjustment to be conductive, and consuming power of the cell requiring balance adjustment through a resistor in the balance adjustment means. The cell balance adjustment method according to any one of claims 11 to 15.

17. and updating, for each of the cells requiring balance adjustment, a remaining balanced energy amount or a balanced capacity of the cell requiring balance adjustment based on a balancing current and a balancing period when the balancing operation is performed on the cell requiring balance adjustment after the balancing operation is performed on the cell requiring balance adjustment.

17. The cell balance adjustment method according to claim 16,

18. The balance adjustment operation condition is: the temperature value of the cell requiring balancing is less than a first temperature threshold; the temperature value of the resistor in the balancing means corresponding to the cell requiring balancing is less than a second temperature threshold; The voltage value of the cell requiring balancing exceeds a voltage threshold; The remaining balance energy or remaining balance capacity of the cell requiring balance adjustment exceeds 0; at least one of:

17. The cell balance adjustment method according to claim 16,

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