Battery equalization method, device, apparatus and computer storage medium

Abstract

The application discloses a battery equalization method, device, equipment and computer storage medium. The battery equalization method comprises the following steps: in the case that the BMS is woken up for the i-th time by using a preset wake-up mode, the historical wake-up data of the BMS is acquired, wherein the preset wake-up mode is a wake-up mode for waking up the BMS based on a preset wake-up period, i is a positive integer; the application state of the battery is determined according to the historical wake-up data; and the battery equalization is performed according to the battery equalization strategy corresponding to the application state. The embodiment of the application enables the battery equalization to enable different battery equalization strategies to be implemented in different application scenarios of the battery, thereby helping the battery to maintain good consistency in the whole life cycle.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a battery equalization method, device, equipment and computer storage medium. BACKGROUND

[0002] Battery equalization generally refers to keeping the voltage deviation of a battery monomer or a battery within an expected range, so as to ensure that each battery monomer maintains the same or similar state in normal use. In the related art, the starting condition of battery equalization is relatively fixed, and it is difficult to adapt to the battery equalization requirements of the battery in various application scenarios. SUMMARY

[0003] Embodiments of the application provide a battery equalization method, device, equipment and computer storage medium, which can improve the problem that the related art is difficult to adapt to the battery equalization requirements of the battery in various application scenarios.

[0004] In a first aspect, embodiments of the application provide a battery equalization method, comprising: in the case that a battery management system (BMS) is awakened using a preset awakening manner for the i th time, acquiring historical awakening data of the BMS, wherein the preset awakening manner is an awakening manner of awakening the BMS based on a preset awakening period, i is a positive integer; determining an application state of the battery according to the historical awakening data; and performing battery equalization according to a battery equalization strategy corresponding to the application state.

[0005] Optionally, determining the application state of the battery according to the historical awakening data comprises: when the historical awakening data indicates that the number of consecutive times of awakening the BMS using the preset awakening manner is greater than or equal to a first threshold, determining the application state of the battery as a stock state; and when the historical awakening data indicates that the number of consecutive times of awakening the BMS using the preset awakening manner is less than the first threshold, determining the application state of the battery as a cyclic use state.

[0006] Optionally, performing battery equalization according to the battery equalization strategy corresponding to the application state comprises: in the case that the application state of the battery is the stock state, acquiring the state of charge of each cell included in the battery, N being an integer greater than 1; respectively acquiring the residual equalization state of charge corresponding to each first cell, the residual equalization state of charge corresponding to the first cell being equal to the difference between the state of charge of the first cell and the state of charge of a second cell, the second cell being the cell with the lowest state of charge among the N cells, and the first cell being a cell other than the second cell among the N cells; determining the residual equalization capacity corresponding to each first cell according to the residual equalization state of charge corresponding to each first cell; and performing battery equalization according to the residual equalization capacity corresponding to each first cell.

[0007] Optionally, the remaining equalization capacity corresponding to each first battery cell is determined according to the remaining equalization state corresponding to each first battery cell, including: obtaining a state of health (SOH) of the first battery cell; and correcting the remaining equalization state corresponding to the first battery cell according to the SOH of the first battery cell to obtain the remaining equalization capacity corresponding to the first battery cell.

[0008] Optionally, the battery equalization is performed according to the remaining equalization capacity corresponding to each first battery cell, including: in a case where the remaining equalization capacity corresponding to at least one first battery cell is greater than a capacity threshold, performing the battery equalization on the battery according to the remaining equalization capacity corresponding to each first battery cell.

[0009] Optionally, before the battery equalization is performed according to the remaining equalization capacity corresponding to each first battery cell, the method further includes: in a case where i is an integer greater than 1, obtaining a first remaining equalization capacity, the first remaining equalization capacity being the remaining equalization capacity corresponding to the first battery cell in a case where the BMS is woken up using the preset wake-up manner for the i-1th time.

[0010] The battery equalization is performed according to the remaining equalization capacity corresponding to each first battery cell, including: in a case where a difference between the second remaining equalization capacity and the first remaining equalization capacity is within a preset threshold range, performing the battery equalization on the battery according to the second remaining equalization capacity, the second remaining equalization capacity being the remaining equalization capacity corresponding to the first battery cell in a case where the BMS is woken up using the preset wake-up manner for the i th time.

[0011] Optionally, the battery equalization is performed according to the battery equalization strategy corresponding to the application state, including: in a case where the application state of the battery is a cyclic use state, using each remaining equalization capacity observer in a preset M number of remaining equalization capacity observers to observe N battery cells included in the battery during charging of the battery to obtain M observation results corresponding to the M number of remaining equalization capacity observers, M being a positive integer; and performing the battery equalization on the battery according to the M observation results.

[0012] The remaining equalization capacity observer is associated with a voltage threshold, and the remaining equalization capacity observer is configured to determine the remaining equalization capacity of any battery cell in a case where the voltage of the battery cell is greater than or equal to the voltage threshold; and any observation result includes the remaining equalization capacity of at least one battery cell determined by the corresponding remaining equalization capacity observer.

[0013] Optionally, the battery equalization is performed according to the M observation results, including: obtaining a characteristic voltage; determining a target observer from the M number of remaining equalization capacity observers according to the characteristic voltage, the target observer being a remaining equalization capacity observer whose associated voltage threshold is greater than or equal to the characteristic voltage and whose difference between the associated voltage threshold and the characteristic voltage is the smallest; and performing the battery equalization on the battery according to the observation result corresponding to the target observer.

[0014] Optionally, before the feature voltage is obtained, the method further comprises: obtaining N cell voltage time series curves of the N cells during charging of the battery; determining a third cell and a target intersection point according to the N cell voltage time series curves, the third cell being a cell with the lowest voltage after charging is completed, and the target intersection point being a last intersection point of a cell voltage time series curve corresponding to the third cell and remaining cell voltage time series curves, the remaining cell voltage time series curves being cell voltage time series curves corresponding to cells other than the third cell among the N cells; and determining the feature voltage based on a voltage of the target intersection point, the feature voltage being greater than or equal to the voltage of the target intersection point.

[0015] Optionally, the remaining equalization capacity observer determines the remaining equalization capacity of any cell when a voltage of the cell is greater than or equal to a voltage threshold, comprising: the remaining equalization capacity observer obtains a real-time charging current of the battery when the voltage of the cell is greater than or equal to the voltage threshold; and the remaining equalization capacity of the cell is obtained by integrating the real-time charging current according to a preset time step.

[0016] Optionally, before each of the M remaining equalization capacity observers is used to observe the N cells included in the battery, the method further comprises: increasing a voltage threshold associated with each of the remaining equalization capacity observers when the battery is still in an application state of aging.

[0017] Optionally, the observation result corresponding to the target observer includes N third remaining equalization capacities corresponding to the N cells, the third remaining equalization capacity being the remaining equalization capacity of the cell determined by the target observer; and the battery is subjected to battery equalization according to the observation result corresponding to the target observer, comprising: the battery is subjected to battery equalization according to the N third remaining equalization capacities when at least one of the third remaining equalization capacities is greater than a capacity threshold.

[0018] Optionally, before the battery is subjected to battery equalization according to the N third remaining equalization capacities, the method further comprises: obtaining a state of charge of a fourth cell and a state of charge of a fifth cell, the fifth cell being a cell with the lowest voltage among the N cells, and the fourth cell being a cell other than the fifth cell among the N cells, and the third remaining equalization capacity of the fourth cell being greater than 0; and determining a fourth remaining equalization capacity of the fourth cell according to a difference between the state of charge of the fourth cell and the state of charge of the fifth cell.

[0019] The battery is subjected to battery equalization according to the N third remaining equalization capacities, comprising: the battery is subjected to battery equalization according to the third remaining equalization capacity when the third remaining equalization capacity is less than or equal to the fourth remaining equalization capacity.

[0020] In a second aspect, the embodiments of the present application provide a battery equalization device, the device comprising: a first acquisition module, configured to acquire historical wakeup data of a BMS in a case that the BMS is woken up for the i th time using a preset wakeup manner, wherein the preset wakeup manner is a wakeup manner of waking up the BMS based on a preset wakeup period, i is a positive integer; a first determination module, configured to determine an application state of the battery according to the historical wakeup data; and an equalization module, configured to perform battery equalization according to a battery equalization strategy corresponding to the application state.

[0021] In a third aspect, the embodiments of the present application provide an electronic device, the device comprising: a processor and a memory storing computer program instructions;

[0022] The processor executes the computer program instructions to implement the battery equalization method as shown in the first aspect.

[0023] In a fourth aspect, the embodiments of the present application provide a computer program product, characterized in that instructions in the computer program product are executed by a processor of an electronic device to cause the electronic device to perform the battery equalization method as shown in the first aspect.

[0024] The battery equalization method provided by the embodiments of the present application acquires historical wakeup data of a BMS in a case that the BMS is woken up for the i th time using a preset wakeup manner, determines an application state of the battery according to the historical wakeup data, and performs battery equalization according to a battery equalization strategy corresponding to the application state, wherein the preset wakeup manner is a wakeup manner of waking up the BMS based on a preset wakeup period. In the embodiments of the present application, the determination of the application state of the battery, the BMS can determine a corresponding battery equalization strategy for each application state, so that different battery equalization strategies can be implemented in different application scenarios of the battery, thereby helping to maintain good consistency of the battery in the whole life cycle. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a specific limitation on the present application.

[0026] Figure 1 is a flowchart of the battery equalization method provided by the embodiments of the present application;

[0027] Figure 2 is an example diagram of a time sequence curve of cell voltages corresponding to a plurality of cells in a battery;

[0028] Figure 3 is a flowchart of the battery equalization method in a specific application example;

[0029] Figure 4is a flowchart of an application scenario determination process of a battery;

[0030] Figure 5 is a flowchart of an operation process of a residual capacity equalization observer;

[0031] Figure 6 is a structural diagram of a battery equalization device provided by an embodiment of the present application;

[0032] Figure 7 is a structural diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0033] The features and exemplary embodiments of various aspects of the present application will be described below in detail, in order to make the purposes, technical solutions and advantages of the present application more clear and apparent, the present application will be further described in detail below in combination with the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, but not to limit the present application. The following description of the embodiments is only to provide a better understanding of the present application by showing examples of the present application.

[0034] It should be noted that, in this document, relational terms such as first and second and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without more limitations, an element defined by the phrase "comprising a" does not exclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0035] In order to improve the problems existing in the prior art, the embodiments of the present application provide a battery equalization method, device, equipment and computer storage medium. First, the battery equalization method provided by the embodiments of the present application will be introduced.

[0036] Figure 1 A flowchart of a battery equalization method provided by an embodiment of the present application is shown. As shown in Figure 1 The method comprises:

[0037] In step 101, in a case that the battery management system (BMS) is woken up by using a preset wake-up manner for the i th time, historical wake-up data of the BMS is acquired, where the preset wake-up manner is a wake-up manner of waking up the BMS based on a preset wake-up period, i is a positive integer;

[0038] In step 102, an application state of the battery is determined according to the historical wake-up data.

[0039] In step 103, battery equalization is performed according to a battery equalization strategy corresponding to the application state.

[0040] The battery equalization method provided by the embodiments of the present application can be applied to the BMS. Alternatively, the battery equalization method can also be applied to a device for managing the battery.

[0041] In some embodiments, the device herein can be an electric device of a type such as an electric vehicle, an electric tool, a drone or an energy storage system. The electric device can include the BMS and the battery as described above.

[0042] In some other embodiments, the device herein can also be an electronic device having a data processing capability in the electric device, or a stand-alone electronic device such as a mobile terminal or a personal computer. For example, the BMS and the battery as described above can be included in a stand-alone battery pack, which can be in a state of inventory, i.e., not yet applied to the electric device. At this time, the BMS can be electrically connected to a stand-alone electronic device such as a personal computer, so that the electronic device can perform the above battery equalization method.

[0043] For simplicity of description, the battery equalization method will be described below by taking the application of the battery equalization method to the BMS as an example.

[0044] In step 101, the BMS can be woken up by using a preset wake-up manner. The preset wake-up manner can be a periodic wake-up manner, i.e., the BMS can be woken up according to a preset wake-up period. It can be understood that the length of the preset wake-up period can be set according to actual requirements, and the preset wake-up period is not limited in the present application.

[0045] In combination with some application scenarios, the battery can be applied to an electric vehicle, and the BMS of the battery can be woken up by a vehicle control unit (VCU) when the electric vehicle is started. Alternatively, the battery can be applied to an energy storage system, and the BMS of the battery can be woken up by an upper controller (e.g., a charge-discharge controller or a system controller of the energy storage system) when the upper controller receives a power supply request.

[0046] In the embodiments of the present application, the preset wake-up manner can be different from the manner of waking up the BMS by the upper controller such as the VCU or the charge-discharge controller. As indicated above, the preset wake-up manner can be a manner of waking up the BMS based on a preset wake-up period. In combination with some examples, the preset wake-up manner can be used to determine the application state of the battery, or the preset wake-up manner can also be used to periodically determine whether the battery reaches the timing of battery equalization.

[0047] In step 101, when the BMS wakes itself up for the i-th time using the preset wake-up manner, the BMS can acquire historical wake-up data of the BMS.

[0048] Generally, the historical wake-up data can include data of the wake-up process experienced by the BMS before the BMS is woken up for the i-th time using the preset wake-up manner, such as the number of wake-ups, the wake-up time, or the wake-up manner, and the like.

[0049] For example, the historical wake-up data can include the number of times the BMS is woken up and the wake-up manner of each wake-up within a preset time period.

[0050] For another example, the historical wake-up data can include the wake-up manner of the previous P times of waking up the BMS before the BMS is woken up for the i-th time using the preset wake-up manner, where P can be a positive integer and can be set as needed, and accordingly, i can be an integer greater than P.

[0051] For yet another example, the BMS counts the number of times the BMS is woken up using the preset wake-up manner in succession, and when the BMS is woken up using a wake-up manner other than the preset wake-up manner, the count can be cleared. In this case, the historical wake-up data can include the number of consecutive times the BMS is woken up using the preset wake-up manner.

[0052] The above are some examples of the historical wake-up data, and in actual applications, the specific content of the historical wake-up data can need to be set, which cannot be exemplified one by one here.

[0053] In step 102, the BMS can determine the application state of the battery according to the historical wake-up data.

[0054] In combination with the above examples, if the historical wake-up data includes the wake-up manner of the previous P times of waking up the BMS, if the wake-up manner of the previous P times of waking up the BMS is all the preset wake-up manner, it indicates that the battery has not been used by the electrical equipment for a long time, and the battery can be currently in a state of inventory or long-term storage. If the wake-up manner of the previous P times of waking up the BMS includes a wake-up manner other than the preset wake-up manner, it indicates that the battery can be currently in a state of cyclic use.

[0055] For example, if the historical wakeup data includes a continuous number of times that the BMS is woken up by using the preset wakeup manner, and the continuous number of times exceeds a preset number of times, it indicates that the battery can be in a storage state or a long-term storage state. If the continuous number of times does not exceed the preset number of times, it indicates that the continuous number of times can be caused by using a wakeup manner other than the preset wakeup manner, and the number of times of waking up the BMS by using the preset wakeup manner is cleared, and the battery can be in a cycle use state.

[0056] For another example, the BMS can count a total number of times of waking up the BMS by using the preset wakeup manner, and determine a use duration of the battery according to the total number of times and a preset wakeup period, and then determine whether the battery is in an aging state.

[0057] In the above examples, the storage state, the cycle use state, or the aging state can be considered as an application state of the battery. The BMS can determine the application state of the battery according to the historical wakeup data.

[0058] In step 103, the BMS can perform battery balancing according to a battery balancing strategy corresponding to the application state.

[0059] In this embodiment, various application states of the battery can be pre-associated with battery balancing strategies.

[0060] For example, when the application state of the battery is the storage state, the battery can be in a long-term stationary state, and open circuit voltages (OCVs) of each cell in the battery can be in a relatively stable state. According to the OCVs of the cells and a state of charge-OCV (SOC-OCV) correspondence relationship, the SOC of each cell can be determined, and the BMS can perform battery balancing according to a difference between the SOCs of the cells.

[0061] For another example, when the application state of the battery is the cycle use state, the battery can undergo a charging process. During the charging process of the battery, the BMS can observe a remaining balancing capacity of each cell, and perform battery balancing based on the observed remaining balancing capacity.

[0062] For another example, when the application state of the battery is the cycle use state, the battery can undergo a discharging process. For example, in an electric vehicle, after the BMS is woken up by the VCU, the battery undergoes a discharging process. After the discharging process is completed and a preset duration is experienced, battery balancing can be performed based on a difference between the SOCs of the cells.

[0063] The above battery balancing according to the difference in SOC between the battery cells, or the balancing according to the observed remaining balancing capacity, can correspond to the above battery balancing strategies, which can have a corresponding relationship with the application state of the battery.

[0064] Of course, the corresponding relationship between the application state and the battery balancing strategy can not be limited to the above examples. For example, in actual application, when the remaining balancing capacity of each battery cell is obtained, the BMS can also determine whether the maximum value of the remaining balancing capacity of the battery cells is greater than a preset capacity threshold. If yes, the BMS controls the balancing of the battery. If no, when the BMS is awakened for the i-th time using the preset awakening manner, the battery can not need to be balanced.

[0065] As for the specific implementation manner of the battery balancing, it can be passive battery balancing, active battery balancing, etc., which is not specifically limited here.

[0066] The passive battery balancing can refer to the balancing manner in which the energy in the high-energy battery is dissipated through a resistor or the like, and the active battery balancing can refer to the manner in which the energy in the high-energy battery is transferred to the low-energy battery. The high and low energy of the battery can be measured by the above-mentioned SOC or remaining balancing capacity, etc., which is not described in detail here.

[0067] As can be seen from the above examples, based on the determination of the application state of the battery, the BMS can determine the corresponding battery balancing strategy according to various application states of the battery, so that different battery balancing strategies can be implemented in different application scenarios of the battery.

[0068] The battery balancing method provided by the embodiment of the application obtains the historical awakening data of the BMS when the BMS is awakened for the i-th time using the preset awakening manner, determines the application state of the battery according to the historical awakening data, and performs battery balancing according to the battery balancing strategy corresponding to the application state, wherein the preset awakening manner is an awakening manner of awakening the BMS based on a preset awakening period. In the embodiment of the application, the determination of the application state of the battery, the BMS can determine the corresponding battery balancing strategy for various application states, so that different battery balancing strategies can be implemented in different application scenarios of the battery, thereby helping to maintain good consistency of the battery in the whole life cycle.

[0069] Optionally, determining the application state of the battery according to the historical awakening data comprises:

[0070] When the historical awakening data indicates that the number of consecutive times of awakening the BMS using the preset awakening manner is greater than or equal to a first threshold, the application state of the battery is determined as a storage state.

[0071] When the historical wake-up data indicates that the number of consecutive times of waking up the BMS using the preset wake-up manner is less than a first threshold, the application state of the battery is determined as a recycling state.

[0072] In this embodiment, the historical wake-up data can indicate the continuity of waking up the BMS using the preset wake-up manner. For example, the historical wake-up data can include the number of consecutive times of waking up the BMS using the preset wake-up manner (hereinafter referred to as the consecutive number).

[0073] The consecutive number can refer to the number of times of waking up the battery management system BMS using the preset wake-up manner before the i-th time of waking up the BMS using the preset wake-up manner. If the BMS is awakened by a wake-up manner other than the preset wake-up manner in the middle, it is considered that the continuity is interrupted, and the consecutive number is cleared.

[0074] Based on the above description, the consecutive number can be used to indicate whether the battery has been in a state of not being awakened by a wake-up manner other than the preset wake-up manner (hereinafter referred to as other wake-up manner) for a long time. If the consecutive number is greater than or equal to a first threshold, it indicates that the battery is in a long-term storage state or a static state, i.e., the application state of the battery is a storage state.

[0075] Conversely, if the consecutive number is less than the first threshold, it indicates that the BMS is awakened by other wake-up manners in the recent period, for example, awakened by the VCU of an electric vehicle or the upper controller of an energy storage system, and the battery can be in a recycling use state, i.e., the application state of the battery can be a recycling use state.

[0076] In this embodiment, according to the consecutive number of waking up the BMS using the preset wake-up manner, the application state of the battery can be determined more accurately, and a reasonable battery balancing strategy can be determined for the battery to balance the battery, thereby improving the feasibility, accuracy and reliability of battery balancing.

[0077] Optionally, balancing the battery according to the battery balancing strategy corresponding to the application state comprises:

[0078] In the case that the application state of the battery is a storage state, the state of charge of each cell included in the battery is obtained, and N is an integer greater than 1;

[0079] The residual balancing state of charge corresponding to each first cell is obtained respectively, the residual balancing state of charge corresponding to the first cell is equal to the difference between the state of charge of the first cell and the state of charge of the second cell, the second cell is the cell with the lowest state of charge among the N cells, and the first cell is the cell other than the second cell among the N cells;

[0080] The residual balancing capacity corresponding to each first cell is determined according to the residual balancing state of charge corresponding to each first cell.

[0081] The battery is balanced according to the residual equalization capacity corresponding to each first cell.

[0082] The embodiment can be considered as a description of the battery balancing strategy corresponding to the inventory state. Specifically, when the battery is in the inventory state, it is often fully rested, and accordingly, the SOC of each cell in the battery can be more accurately detected at this time.

[0083] In some examples, the SOC of each cell can be obtained based on the detection of the OCV of the cell, in combination with the SOC-OCV correspondence. Alternatively, the temperature of the battery, or the temperature of each cell, can also be obtained, and the matched SOC-OCV correspondence is determined according to the obtained temperature, and the SOC of the cell is further determined in combination with the detected OCV.

[0084] In other examples, the SOC of each cell can also be obtained based on coulomb counting, etc.

[0085] In the embodiment, the BMS can obtain the SOC of each cell, and on this basis, the BMS can determine the cell with the lowest SOC, i.e., the second cell described above.

[0086] After determining the second cell, the BMS can subtract the SOC of each cell (i.e., the first cell described above) from the SOC of the second cell to obtain the residual equalization state of charge corresponding to each first cell.

[0087] In a specific implementation manner, the battery includes N cells, and the second cell is the cell with the lowest SOC among the N cells. In an example, the number of second cells can be 1, and the number of first cells can be N-1, which are the cells other than the second cell among the N cells. Of course, in other examples, there can be a case where multiple cells have equal SOC and are the lowest, and the number of first cells and second cells will change accordingly, which will not be exemplified one by one here.

[0088] In some examples, after the residual equalization state of charge corresponding to each first cell is determined, the BMS can take the residual equalization state of charge as the residual equalization capacity. Alternatively, the BMS can also correct or convert the residual equalization state of charge according to other parameters to obtain the residual equalization capacity.

[0089] When the strategy of the battery balancing is passive battery balancing, the residual equalization capacity corresponding to one cell can be the capacity that needs to be consumed by the cell in the passive battery balancing process.

[0090] In this embodiment, based on the acquisition of the state of charge of each cell in the battery, the remaining equalization capacity of each first cell is determined, which can be more convenient to perform battery equalization when the battery is in a stock state.

[0091] In some embodiments, the BMS can also perform battery equalization on the battery in combination with the state of health (SOH) of each first cell.

[0092] Specifically, according to the remaining equalization state of charge corresponding to each first cell, each first cell is equalized, including:

[0093] Acquire the state of health (SOH) of the first cell;

[0094] According to the SOH of the first cell, the remaining equalization state of charge corresponding to the first cell is corrected to obtain the remaining equalization capacity corresponding to the first cell.

[0095] Here, the first cell can be any of the above first cells. In some examples, the SOH of the first cell can be obtained by dividing the actual capacity of the first cell by the nominal capacity.

[0096] After obtaining the SOH of the first cell, the BMS can use the SOH to correct the remaining equalization state of charge corresponding to the first cell, such as multiplying the remaining equalization state of charge by the SOH, or combining other preset conversion relationships to obtain the remaining equalization capacity corresponding to the first cell.

[0097] In combination with some actual application scenarios, when passive battery equalization is performed on the battery, the BMS can control the opening and closing of the relevant equalization channel based on the remaining equalization capacity corresponding to the first cell, which can be used to realize self-consumption of the battery, so that each first cell can consume or approximately consume the corresponding remaining equalization capacity.

[0098] In this embodiment, considering the SOH of each first cell, the remaining equalization capacity of the cell that needs to be equalized can be more consistent with the actual charge and discharge capacity, which helps to improve the consistency between the cells after battery equalization.

[0099] Optionally, according to the remaining equalization capacity corresponding to each first cell, the battery is equalized, including:

[0100] In a case where the remaining equalization capacity corresponding to at least one first cell is greater than a capacity threshold, the battery is equalized according to the remaining equalization capacity corresponding to each first cell.

[0101] In this embodiment, the BMS can perform battery balancing based on the residual balancing capacity of each first battery cell when the residual balancing capacity of at least one first battery cell is greater than the capacity threshold. In other words, when the maximum value of the residual balancing capacity of the first battery cell is greater than the capacity threshold, the BMS can start battery balancing.

[0102] In this embodiment, the BMS performs battery balancing when the residual balancing capacity of any first battery cell is greater than the capacity threshold, which can also prevent battery balancing from being too frequent.

[0103] Optionally, before performing battery balancing on the battery according to the residual balancing capacity of each first battery cell, the method further includes:

[0104] When i is an integer greater than 1, the first residual balancing capacity is obtained, which is the residual balancing capacity of the first battery cell when the BMS is awakened using the preset awakening manner for the i-1th time.

[0105] Performing battery balancing on the battery according to the residual balancing capacity of each first battery cell includes:

[0106] When the difference between the second residual balancing capacity and the first residual balancing capacity is within a preset threshold range, performing battery balancing on the battery according to the second residual balancing capacity, which is the residual balancing capacity of the first battery cell when the BMS is awakened using the preset awakening manner for the i th time.

[0107] Considering that the sampling of the OCV or SOC of the battery cell may have errors, in this embodiment, in order to reduce the determination error of the residual balancing capacity of each first battery cell caused by sampling errors, the residual balancing capacity of the first battery cell determined in the history can be combined to reduce the influence of single sampling error.

[0108] Specifically, since the above-mentioned preset awakening manner is to awaken the BMS according to a preset awakening period, accordingly, when it is determined that the battery is in the inventory state, the BMS may need to determine the second battery cell and calculate the residual balancing capacity of each first battery cell after awakening the BMS according to the preset awakening manner each time.

[0109] Accordingly, the BMS can determine the residual balancing capacity of each first battery cell when the BMS is awakened using the preset awakening manner for the i-1th time, i.e., the first residual balancing capacity mentioned above. When the BMS is awakened using the preset awakening manner for the i th time, the first residual balancing capacity can be considered as the residual balancing capacity of the first battery cell determined in the history.

[0110] When the BMS wakes up itself using the preset wake-up manner for the i-th time, the BMS can also determine the remaining equalization capacity corresponding to the first battery cell, and the remaining equalization capacity at this time can be the second remaining equalization capacity.

[0111] It is easy to understand that when the battery is in the inventory state, after a time interval of a preset wake-up period, the change amount of the remaining equalization capacity of the first battery cell determined each time is relatively stable, that is, the change amount of the remaining equalization capacity corresponding to the first battery cell determined each time is generally within a reasonable interval. When the change amount exceeds the reasonable interval, it indicates that there is a large error in sampling the related parameters of the first battery cell or the second battery cell.

[0112] Specifically in this embodiment, the change amount of the remaining equalization capacity of the first battery cell can be the difference between the second remaining equalization capacity and the first remaining equalization capacity. The change amount being within the reasonable interval can correspond to the difference between the second remaining equalization capacity and the first remaining equalization capacity being within a preset threshold range.

[0113] In this embodiment, when the difference between the second remaining equalization capacity and the first remaining equalization capacity is within the preset threshold range, it can be considered that the sampling result of the second remaining equalization capacity is accurate, and thus the second remaining equalization capacity is taken as the capacity that needs to be equalized away from the first battery cell in the process of battery equalization.

[0114] This embodiment can avoid that a single sampling error greatly affects the calculation of the remaining equalization capacity, and prevent the battery from being abnormally equalized.

[0115] In some embodiments, when the difference between the second remaining equalization capacity and the first remaining equalization capacity is not within the preset threshold range, the first remaining equalization capacity can be taken as the capacity that needs to be equalized away from the first battery cell. Alternatively, the BMS can also resample the second remaining equalization capacity of the first battery cell. Alternatively, the BMS can also terminate the current battery equalization process, and perform battery equalization again when the BMS is woken up using the preset wake-up manner for the i+1-th time.

[0116] In some embodiments, in the case where the BMS is woken up using the preset wake-up manner for the i-th time, if the remaining equalization capacity corresponding to each first battery cell is less than or equal to the capacity threshold, the battery can not need to be equalized.

[0117] In addition, in the case where the battery does not need to be equalized, the BMS can still obtain the first remaining equalization capacity. When the difference between the second remaining equalization capacity and the first remaining equalization capacity is not within the preset threshold range, the BMS can update the second remaining equalization capacity to the first remaining equalization capacity.

[0118] In other words, when the difference between the second residual balance capacity and the first residual balance capacity is not within the preset threshold range, the BMS can consider that the first residual balance capacity corresponding to the first battery cell obtained after the BMS is awakened i times using the preset awakening manner is inaccurate, and use the last obtained first residual balance capacity as the current obtained first residual balance capacity.

[0119] Optionally, the battery balancing according to the battery balancing strategy corresponding to the application state comprises:

[0120] In the case where the application state of the battery is the cyclic use state, during the charging of the battery, each residual balance capacity observer in the preset M residual balance capacity observers is used to observe the N battery cells to obtain M observation results corresponding to the M residual balance capacity observers, M being a positive integer.

[0121] The battery is balanced according to the M observation results.

[0122] The residual balance capacity observer is associated with a voltage threshold, and the residual balance capacity observer is used to determine the residual balance capacity of any battery cell when the voltage of any battery cell is greater than or equal to the voltage threshold; and any observation result comprises the residual balance capacity of at least one battery cell determined by the corresponding residual balance capacity observer.

[0123] When the application state of the battery is the cyclic use state, the battery usually has a charging process, and in the embodiment, the BMS can determine the residual balance capacity of each battery cell during the charging of the battery, so as to further balance the battery based on the residual balance capacity.

[0124] Specifically, in the embodiment, at least one residual balance capacity observer can be used to observe each battery cell in the battery during the charging of the battery. The residual balance capacity observer can be integrated in the BMS. Alternatively, the residual balance capacity observer can be a circuit with data processing capability, such as a microprocessor, independent of the BMS, and the residual balance capacity observer is electrically connected with the BMS to realize the transmission of data between the two.

[0125] Each residual balance capacity observer can be associated with a voltage threshold, which can be set according to actual needs.

[0126] In some embodiments, when the battery includes a ternary battery cell, the voltage threshold can be set based on the regular working voltage of the ternary battery cell, 3.6V, for example, and the voltage threshold can be determined as 3.6V or a voltage value slightly less than 3.6V. In practical applications, the battery can also include a lithium-manganese battery cell (regular working voltage of 3.7V) or a lithium-iron-phosphate battery cell (regular working voltage of 3.2V), etc., and the voltage threshold can also be set according to the working voltage of the corresponding type of cell.

[0127] In one embodiment, the voltage threshold of the remaining equalization capacity observer can also be directly set as the nominal voltage of the battery.

[0128] In other embodiments, the voltage threshold associated with each remaining equalization capacity observer can also be updated according to the voltage change curve of each cell during the charging of the battery, etc., without specific limitation here.

[0129] When there are multiple remaining equalization capacity observers, the voltage thresholds associated with these remaining equalization capacity observers can be equal or unequal.

[0130] In combination with some examples, when the associated voltage thresholds are equal, the remaining equalization capacity observers can play a role of redundant setting; and when the associated voltage thresholds are unequal, the BMS can select a remaining equalization capacity observer with a more appropriate voltage threshold according to the voltage change of the cell during the charging of the battery, and perform battery equalization based on the observation results of the selected remaining equalization capacity observer. For example, the more appropriate voltage threshold can be greater than the voltage reference value and less than the nominal voltage of the battery, etc. Of course, this is an exemplary description of the selection method of the remaining equalization capacity observer, and other selection methods of the remaining equalization capacity observer will be further described in the following embodiments.

[0131] For example, if the voltage threshold associated with a remaining equalization capacity observer is 3.6V, the remaining equalization capacity observer can obtain the voltage of each cell in the battery during the charging of the battery. When the voltage of any cell is greater than or equal to 3.6V, the remaining equalization capacity observer can estimate the remaining equalization capacity of the cell.

[0132] For example, when the remaining equalization capacity is in ampere-hours, the remaining equalization capacity observer can obtain the real-time charging current of the battery, and integrate the real-time charging current based on time to obtain the remaining equalization capacity of the cell.

[0133] In one embodiment, the remaining equalization capacity observer determines the remaining equalization capacity of any cell when the voltage of any cell is greater than or equal to the voltage threshold, including:

[0134] The remaining equalization capacity observer obtains the real-time charging current of the battery when the voltage of the battery cell is greater than or equal to the voltage threshold value;

[0135] The remaining equalization capacity of the battery cell is obtained by integrating the real-time charging current according to the preset time step.

[0136] In an example, for a remaining equalization capacity observer, the associated voltage threshold value is V f When the voltage V j of the jth battery cell is greater than or equal to V f , the remaining equalization capacity observer starts to estimate the remaining equalization capacity of the battery cell by integration, and the formula is as follows:

[0137]

[0138] Wherein, is the estimated remaining equalization capacity; the subscript j represents the cell number, and the subscript k is the time index, representing the kth moment; I is the charging current of the battery, I k may correspond to the above-mentioned real-time charging current; and Δt is the above-mentioned preset time step, corresponding to the time length between the k-1th moment and the kth moment.

[0139] In this embodiment, the real-time charging current is integrated according to the preset time step, which helps to make the obtained remaining equalization capacity of the battery cell more reasonable and accurate, and further helps to improve the subsequent battery equalization effect.

[0140] Of course, the remaining equalization capacity observer can also estimate the remaining equalization capacity of each battery cell based on the acquisition of other parameters during the charging process or other calculation methods, which can be set as needed, and will not be exemplified here.

[0141] Each remaining equalization capacity observer can determine the remaining equalization capacity of the above-mentioned N battery cells, and accordingly, the observation result obtained by each remaining equalization capacity observer can include the remaining equalization capacity of the N battery cells.

[0142] In this embodiment, the BMS can perform battery equalization on the battery according to the M observation results.

[0143] In some examples, M can be equal to 1, so that the detection result can include the remaining equalization capacity of each battery cell, and the BMS can equalize each battery cell according to the remaining equalization capacity.

[0144] In some examples, M can be greater than 1, the voltage threshold value selected by the plurality of residual equalization capacity observers can be different, and the BMS can determine a characteristic voltage as a reference according to the voltage change of each battery cell during the battery charging process, and take the detection result of the residual equalization capacity observer with the voltage threshold value close to the characteristic voltage as the basis for battery equalization. The specific determination method of the characteristic voltage will be described in detail below.

[0145] In some examples, M can be greater than 1, the voltage threshold value selected by the plurality of residual equalization capacity observers can be different, and the BMS can determine a characteristic voltage as a reference according to the voltage change of each battery cell during the battery charging process, and take the detection result of the residual equalization capacity observer with the voltage threshold value close to the characteristic voltage as the basis for battery equalization. The specific determination method of the characteristic voltage will be described in detail below.

[0146] The above is an example of the BMS performing battery equalization on the battery according to the M observation results. In actual application, the specific battery equalization method can be set as needed, and examples are not given here.

[0147] In the embodiment, when the application state of the battery is the cycle use state, the observation result of the residual equalization capacity observer is used to perform battery equalization on the battery, which helps the BMS to conveniently perform battery equalization when the battery is in the cycle use state.

[0148] Optionally, performing battery equalization on the battery according to the M observation results comprises:

[0149] Obtaining a characteristic voltage;

[0150] Determining a target observer from the M residual equalization capacity observers according to the characteristic voltage, the target observer being the residual equalization capacity observer with the associated voltage threshold value greater than or equal to the characteristic voltage and the minimum difference between the associated voltage threshold value and the characteristic voltage;

[0151] Performing battery equalization on the battery according to the observation result corresponding to the target observer.

[0152] In some examples, the characteristic voltage described above can be obtained through pre-calibration of the battery, or the characteristic voltage can be adjusted according to the cycle use times or aging condition of the battery, etc.

[0153] In combination with some application examples, the characteristic voltage can be determined according to the lowest voltage battery cell in the battery. For example, the characteristic voltage can be the voltage of the lowest voltage battery cell in the full charge state of the battery, or the voltage value less than the lowest voltage battery cell, etc.

[0154] In the embodiment, the BMS can determine a target observer from the M residual equalization capacity observers according to the characteristic voltage.

[0155] As shown above, each residual equalization capacity observer can be associated with a voltage threshold, and the voltage threshold associated with the target observer can satisfy the following conditions: one is greater than or equal to the characteristic voltage, and the other is the minimum difference from the characteristic voltage.

[0156] The BMS performs battery equalization according to the observation result of the target observer.

[0157] The voltage threshold associated with the target observer being greater than or equal to the characteristic voltage can avoid the residual equalization capacity observer starting to estimate the residual equalization capacity from a lower voltage starting point during battery charging, resulting in excessive equalization when the battery is equalized.

[0158] And the voltage threshold associated with the target observer being the minimum difference from the characteristic voltage helps to fully estimate the residual equalization capacity of each cell and improve the battery equalization effect.

[0159] Optionally, before obtaining the characteristic voltage, the method further comprises:

[0160] Obtaining N cell voltage time series curves corresponding to N cells during battery charging;

[0161] According to the N cell voltage time series curves, determining a third cell and a target intersection point, the third cell being the lowest voltage cell after charging is completed, and the target intersection point being the last intersection point in time series of the cell voltage time series curve corresponding to the third cell and the remaining cell voltage time series curves, the remaining cell voltage time series curves being the cell voltage time series curves corresponding to the cells other than the third cell among the N cells;

[0162] Based on the voltage of the target intersection point, determining the characteristic voltage, the characteristic voltage being greater than or equal to the voltage of the target intersection point.

[0163] The embodiment provides a way to obtain the characteristic voltage.

[0164] Specifically, the BMS obtains the cell voltage time series curves of each cell during battery charging, i.e., the curve of the change of the voltage of the cell with the charging time.

[0165] As shown in Figure 2 , the cell voltage time series curves corresponding to the plurality of cells are shown in the following figure. Figure 2 Each curve corresponds to the charging process of a cell.

[0166] Based on Figure 2 It can be seen that there can be differences in the charging cutoff voltages between the cells after charging is completed (corresponding to the cutoff time). Among them, the cell with the minimum charging cutoff voltage can correspond to the third cell, i.e., the lowest voltage cell after charging is completed.

[0167] Based on Figure 2It can be seen that the cell voltage time sequence curve corresponding to the third cell can have intersection points with the cell voltage time sequence curves of the remaining cells, and each intersection point corresponds to a voltage value.

[0168] In this embodiment, the last intersection point of the cell voltage time sequence curve corresponding to the third cell in time sequence can be selected as the target intersection point, and the target intersection point can also correspond to a voltage value.

[0169] The BMS can determine the characteristic voltage based on the voltage of the target intersection point. For example, the BMS can directly use the voltage of the target intersection point as the characteristic voltage. Alternatively, the BMS can determine the characteristic voltage to be greater than the voltage of the target intersection point.

[0170] Generally, in the process of battery balancing, the cell with the lowest voltage is usually taken as a reference for battery balancing, so that the capacities of the cells in the battery are approximately similar to the capacity of the cell with the lowest voltage after balancing. In combination with the above description, the characteristic voltage is determined to be greater than the voltage of the target intersection point, so that the cell with the lowest voltage is not balanced, and the occurrence of false balancing is reduced. Figure 2 It can be seen that determining the characteristic voltage to be greater than the voltage of the target intersection point can effectively avoid balancing the cell with the lowest voltage and reduce the occurrence of false balancing.

[0171] Optionally, the observation result corresponding to the target observer includes N third residual balancing capacities corresponding to the N cells, and the third residual balancing capacity is a residual balancing capacity of a cell determined by the target observer.

[0172] According to the observation result corresponding to the target observer, the battery is balanced, including:

[0173] In a case where at least one third residual balancing capacity is greater than the capacity threshold, the battery is balanced according to the N third residual balancing capacities.

[0174] The target observer belongs to M residual balancing capacity observers, for example, the target observer is one of the M residual balancing capacity observers, and correspondingly, the above-described manner in which the residual balancing capacity observer determines the residual balancing capacity of the cell is also applicable to the process in which the target observer determines the residual balancing capacity of the cell. The third residual balancing capacity can refer to the residual balancing capacity of the cell determined by the target observer.

[0175] In this embodiment, the BMS balances the battery in a case where at least one third residual balancing capacity is greater than the capacity threshold, which can avoid excessively frequent balancing of the battery.

[0176] In some embodiments, the capacity threshold can be a parameter pre-set in the BMS.

[0177] Optionally, before observing the N battery cells included in the battery respectively using each of the preset M residual equalization capacity observers, the method further comprises:

[0178] In the case that the battery is still in the aging application state, the voltage threshold associated with each residual equalization capacity observer is adjusted upward.

[0179] In combination with the above, the application state of the battery can be a stock state, a cyclic use state, or an aging state, etc.

[0180] That is, in the embodiment, it can be determined whether the battery is in the aging application state.

[0181] In some examples, whether the battery is in the aging application state can be determined based on the number of times the BMS is awakened by the preset wake-up mode, as shown above.

[0182] In other examples, the BMS can obtain the total number of cycles of the battery, and in the case that the total number of cycles is greater than a cycle number threshold, it is determined that the battery is in the aging application state.

[0183] Alternatively, the BMS can obtain the total application time length of the battery, and in the case that the total application time length is greater than a time length threshold, it is determined that the battery is in the aging application state.

[0184] In some examples, the total number of cycles of the battery can be obtained by conversion according to the charge and discharge ampere-hour throughput and the nominal capacity of the battery, where the charge and discharge ampere-hour throughput refers to the cumulative charge and discharge capacity of the battery in the life cycle, that is, it includes the charge capacity and the discharge capacity. The total time length can be obtained by starting to accumulate after the battery cells are grouped.

[0185] When the battery as a whole is in the aging state, because the internal resistance or the capacity characteristics change greatly with aging, in order to reduce the risk of false equalization, the voltage threshold associated with each residual equalization capacity observer can be adjusted upward as a whole.

[0186] In some examples, in the case that the battery is not in the aging application state, the voltage threshold associated with each residual equalization capacity observer can be determined in advance. In the case that the battery is in the aging application state, the BMS can add a preset voltage value to the determined voltage threshold or multiply the determined voltage threshold by a preset coefficient to achieve the upward adjustment of the voltage threshold.

[0187] In some embodiments, when the battery is in the aging application state, the BMS can also adjust the voltage threshold of the residual equalization capacity observer according to the aging degree of the battery. The aging degree of the battery can be determined according to the total number of cycles or the total application time length described above.

[0188] Optionally, before performing the battery equalization on the battery according to the N third residual equalization capacities, the method further comprises:

[0189] obtaining a state of charge of a fourth battery cell and a state of charge of a fifth battery cell, the fifth battery cell being a lowest voltage battery cell among the N battery cells, and the fourth battery cell being a battery cell among the N battery cells other than the fifth battery cell, and the third residual equalization capacity of the fourth battery cell being greater than 0. It can be understood that the fourth battery cell can be a battery cell whose voltage exceeds the voltage threshold associated with the residual equalization capacity observer during the charging process;

[0190] determining a fourth residual equalization capacity of the fourth battery cell according to a difference between the state of charge of the fourth battery cell and the state of charge of the fifth battery cell;

[0191] performing the battery equalization on the battery according to the N third residual equalization capacities, comprising:

[0192] in a case where the third residual equalization capacity is less than or equal to the fourth residual equalization capacity, performing the battery equalization on the battery according to the third residual equalization capacity.

[0193] When the battery is in the application state of aging, the observation result corresponding to the target observer can not be reliable, and at this time, directly performing the battery equalization according to the observation result can lead to poor battery equalization effect.

[0194] In the embodiment, in addition to being able to use the residual equalization capacity observer to obtain the residual equalization capacity of the battery cell, the BMS can also determine the residual equalization capacity of the battery cell by means similar to those adopted when the battery is in the inventory state.

[0195] Specifically, among the means similar to those adopted when the battery is in the inventory state, the BMS can determine a lowest voltage battery cell from the N battery cells of the battery, which can correspond to the fifth battery cell described above, and the battery cells among the N battery cells other than the fifth battery cell can be the fourth battery cell described above.

[0196] In one example, the battery includes N battery cells, the fifth battery cell is a battery cell with the lowest SOC among the N battery cells, and the corresponding number is 1. The fourth battery cell is a battery cell among the N battery cells other than the fifth battery cell, and the third residual equalization capacity of the fourth battery cell is greater than 0, and the number of the fourth battery cell can be less than or equal to N-1.

[0197] In some embodiments, the fifth battery cell can be the third battery cell mentioned in the above embodiment.

[0198] And in some other embodiments, the third battery cell is a battery cell with the lowest battery cell voltage used when determining the characteristic voltage, and the fifth battery cell can be a battery cell with the lowest battery cell voltage used in each battery equalization.

[0199] The fourth remaining equalization capacity of the fourth battery cell can also be obtained based on the difference between the state of charge of the fourth battery cell and the state of charge of the fifth battery cell. For example, the fourth remaining equalization capacity can be equal to the difference, or the fourth remaining equalization capacity can also be a value obtained by correcting the difference using the SOH of the fourth battery cell.

[0200] The fourth remaining equalization capacity of the fourth battery cell can also be obtained based on the difference between the state of charge of the fourth battery cell and the state of charge of the fifth battery cell. For example, the fourth remaining equalization capacity can be equal to the difference, or the fourth remaining equalization capacity can also be a value obtained by correcting the difference using the SOH of the fourth battery cell.

[0201] The fourth remaining equalization capacity of the fourth battery cell can also be obtained based on the difference between the state of charge of the fourth battery cell and the state of charge of the fifth battery cell. For example, the fourth remaining equalization capacity can be equal to the difference, or the fourth remaining equalization capacity can also be a value obtained by correcting the difference using the SOH of the fourth battery cell.

[0202] It can be understood that the third remaining equalization capacity is determined by the target observer. The target observer only starts to accumulate the third remaining equalization capacity when it is detected that the voltage of the battery cell is greater than the voltage threshold. During the charging process, the voltage of some battery cells does not reach the voltage threshold, and therefore the third remaining equalization capacity can be equal to 0. In this embodiment, the third remaining equalization capacity of the fourth battery cell can be greater than 0, that is, the fourth battery cell can be a battery cell that needs to be equalized based on the target observer.

[0203] The fourth remaining equalization capacity reflects the maximum equalization amount of the fourth battery cell. If the third remaining equalization capacity is greater than the fourth remaining equalization capacity, and the fourth battery cell is equalized according to the third remaining equalization capacity, over-equalization can occur. Therefore, under normal circumstances, the third remaining equalization capacity is less than or equal to the fourth remaining equalization capacity, otherwise, it can be considered that the target observer's observation result deviates from the actual equalization demand due to factors such as battery aging.

[0204] Therefore, in this embodiment, when the third remaining equalization capacity is less than or equal to the fourth remaining equalization capacity, the fourth battery cell is equalized, thereby reducing the risk of mis-equalization.

[0205] In some embodiments, when the third remaining equalization capacity is greater than the fourth remaining equalization capacity, the fourth remaining equalization capacity can be used as the capacity that needs to be equalized for the fourth battery cell. Alternatively, the third remaining equalization capacity obtained when the fourth battery cell wakes up itself last time (i-1 times using the preset wake-up method) can be used as the capacity that needs to be equalized for the fourth battery cell.

[0206] In other embodiments, without the need to balance the batteries, the BMS can still obtain the fourth remaining balanced capacity. When the third remaining balanced capacity of any fourth battery cell is greater than the fourth remaining balanced capacity, for the fourth battery cell, the BMS can use the third remaining balanced capacity obtained when it was awakened last time (the i-1th time using the preset wake-up method) as the third remaining balanced capacity obtained when it is awakened this time (the i-th time using the preset wake-up method).

[0207] The following describes the battery balancing method provided by the embodiment of the present application in conjunction with some specific application examples. Figure 3 As shown, the battery balancing method includes steps 301 to 308.

[0208] Step 301 : Set the BMS timer wake-up period and the number of cycles and duration for the battery to enter the aging stage.

[0209] Among them, timed wake-up can refer to the process in which the BMS software actively wakes up the battery after a certain period of time (corresponding to a preset wake-up period) after the battery enters sleep mode under no current and no communication conditions.

[0210] Step 302 : Determine the application scenario of the battery based on the accumulated number of timed wake-up times, the total number of cycles, and the total application duration.

[0211] The application scenario here may correspond to the above-mentioned application state.

[0212] like Figure 4 As shown, in step 302, when the total number of cycles or the total application time exceeds the corresponding preset threshold, it is determined that the battery pack is in an aging scenario (corresponding to the above-mentioned aging state); otherwise, it is in a non-aging scenario.

[0213] The total number of cycles is calculated based on the charge and discharge ampere-hour throughput and battery capacity; the total application time starts to accumulate after the battery cells are grouped.

[0214] The BMS further refines the usage scenario based on the cumulative number of timed wake-ups. If the cumulative number of timed wake-ups exceeds the set threshold, the battery is determined to be in long-term storage (corresponding to the inventory status mentioned above); otherwise, it is determined to be in recycling (corresponding to the recycling status mentioned above).

[0215] The accumulated timed wake-up times are accumulated by the BMS, and the counter is incremented by 1 after each timed wake-up. When the system wakes up due to other events, the counter is cleared to 0.

[0216] Step 303: Match the remaining balancing capacity estimation method according to the application scenario.

[0217] This step corresponds to determining the corresponding battery equalization strategy according to the application state of the battery in the above.

[0218] Step 304, when the battery is in a long-term storage inventory scenario, the SOC difference is obtained through the OCV-SOC relationship according to the terminal voltage of each cell after each timed wake-up, and the remaining equalization capacity is converted.

[0219] Specifically, after judging that the long-term storage storage scenario is entered, the BMS collects the terminal voltage and temperature of each cell after each timed wake-up, obtains the SOC of each cell through the temperature-OCV-SOC relationship table lookup, and obtains the remaining equalization SOC of each cell by subtracting the lowest SOC cell, and converts the remaining equalization capacity of each cell through the nominal capacity and SOH.

[0220] To avoid the influence of single sampling error on the calculation of the remaining equalization capacity, the remaining equalization capacity calculated under the current wake-up condition is compared with the remaining equalization capacity calculated at the last wake-up. When the difference is within the preset threshold range, the calculated value is considered valid and is updated; otherwise, the remaining equalization capacity is not updated.

[0221] Step 305, when the battery is in a cycle use scenario, the BMS runs multiple remaining equalization capacity observers in parallel, and selects the optimal remaining equalization capacity observer result as the remaining equalization capacity according to the lowest voltage cell when the battery is fully charged.

[0222] Specifically, the working process of the remaining capacity equalization observer is as shown in Figure 5 .

[0223] 1) When the battery is in a stable charging state, the remaining equalization capacity observer starts to work;

[0224] The stable charging state here can refer to the state of the battery after a preset time duration after the charging is started.

[0225] 2) Determine whether each cell exceeds the set voltage feature point V f When the voltage V j of a cell is greater than or equal to V f , the integral of the estimated remaining equalization capacity of the cell is started, and the formula is as follows:

[0226]

[0227] Wherein, is the estimated remaining equalization capacity; subscript j represents the cell number, and subscript k is the time index, indicating the kth moment; I is the charging current of the battery, I k may correspond to the real-time charging current described above; Δt is the preset time step described above, corresponding to the time duration between the k-1th moment and the kth moment.

[0228] 3) When the minimum cell voltage (corresponding to min(V)) reaches the voltage feature point V f or the maximum cell voltage (corresponding to max(V)) reaches the full charge voltage or the charging process is interrupted, stop the integration of the remaining equalization capacity of all cells and output it as the remaining equalization capacity of each cell.

[0229] 4) After the charging is completed, that is, reset the remaining equalization capacity in the remaining capacity equalization observer for the next time the BMS wakes up, and the remaining equalization capacity is estimated by the remaining capacity equalization observer.

[0230] As shown in FIG. 2, when the characteristic voltage is set below the target intersection point, the remaining equalization capacity calculated by the lowest voltage cell at full charge will be greater than 0, which will cause the occurrence of a false equalization condition.

[0231] Therefore, in this step, multiple remaining equalization capacity observers associated with different voltage thresholds are run in parallel to estimate the remaining equalization capacity of the cells. When the battery pack is fully charged, the optimal remaining equalization capacity observer result is selected according to the voltage feature point (corresponding to the characteristic voltage) as the remaining equalization capacity.

[0232] Voltage feature point selection principle: 1) Record the intersection point of the lowest voltage cell during charging; 2) Select the feature point above the target intersection point.

[0233] The selection of the optimal remaining equalization capacity observer result corresponds to the selection process of the target observer and its remaining equalization capacity in the above embodiment, which is not repeated here.

[0234] Step 306: When in the aging scenario, the voltage threshold of the remaining equalization capacity observer is adjusted upward as a whole; when the remaining equalization capacity obtained by the equalization capacity observer (corresponding to the third remaining equalization capacity) is less than or equal to the remaining equalization capacity obtained by the SOC difference conversion (corresponding to the fourth remaining equalization capacity), update the remaining equalization capacity; otherwise, do not update.

[0235] Specifically, when the battery pack as a whole is in the aging scenario, since the internal resistance / capacity and other characteristics have changed greatly with aging, in order to reduce the risk of false equalization, the voltage threshold of each remaining equalization capacity observer will be adjusted upward as a whole.

[0236] In addition, in the post-aging cyclic use scenario, when the remaining equalization capacity obtained by the equalization capacity observer (corresponding to the third remaining equalization capacity) is greater than the value obtained by the SOC difference conversion under the long-term storage condition after aging (corresponding to the fourth remaining equalization capacity), it is considered that this estimation is invalid and is not updated.

[0237] Step 307, according to the remaining equalization capacity of each cell, determine whether to force wake up for passive battery equalization.

[0238] Specifically, a threshold value (corresponding to the capacity threshold value) is set in advance to determine whether the remaining equalization capacity is too large, the maximum value of the current remaining equalization capacity of each cell is obtained, and when the value is greater than the capacity threshold value, the sleep is shielded to make the BMS continuously wake up for passive equalization action; otherwise, the BMS normally enters the sleep state.

[0239] Step 308, according to the remaining equalization capacity of each cell, control the opening / closing of each equalization channel, and update the remaining equalization capacity in real time according to the opening / closing state.

[0240] Specifically, when the remaining equalization capacity of the cell is greater than 0, the BMS controls the equalization channel corresponding to the cell to be opened, the equalization resistance is arranged on the equalization channel, and the electric quantity is dissipated through the equalization resistance. The update process of the remaining equalization capacity of each cell in the passive equalization process is as follows:

[0241]

[0242] In the formula, Q bal , R bal , V, and Switch represent the remaining equalization capacity, the equalization resistance, the cell voltage, and the opening / closing state of the equalization channel (the opening state is equal to 1, and the closing state is equal to 0) respectively; the subscript j represents the cell label, and the subscript k represents the time index, indicating the kth moment; and Δt is the running period.

[0243] When the calculation of the remaining equalization capacity is completed in step 304, step 305, or step 306, in step 307, Before being cleared, Q bal is updated to an estimated value, that is,

[0244] The battery equalization method provided by the embodiment of the application can face the whole cycle after the battery grouping application, actively identify the three scenes of inventory (long-term storage), cyclic use and aging, and dynamically adapt the update method of the remaining equalization capacity according to different scenes, more accurately and effectively estimate the equalization capacity of each cell and realize passive equalization.

[0245] The method is not limited to a specific application scene, and the equalization action can be performed in any scene, and the equalization efficiency is high; at the same time, the reasonable adaptation of the update method reduces the risk of mis-equalization. Through the efficient and accurate equalization process, the requirements of the battery grouping and capacity distribution process will be relaxed, the development of the inconsistency of the battery pack is better inhibited, the service life of the battery pack is prolonged, and there is great practical and economic benefit.

[0246] For example, Figure 6As shown, the embodiment of the present application further provides a battery equalization device, the device comprises:

[0247] The first acquisition module 601 is configured to acquire historical wakeup data of the BMS in a case that the preset wakeup mode is used for the i th time to wake up the BMS, wherein the preset wakeup mode is a wakeup mode for waking up the BMS based on a preset wakeup period, i is a positive integer, and the historical wakeup data is used to indicate a number of times that the preset wakeup mode is used to wake up the BMS.

[0248] The first determination module 602 is configured to determine an application state of the battery according to the historical wakeup data.

[0249] The equalization module 603 is configured to perform battery equalization according to a battery equalization strategy corresponding to the application state.

[0250] Optionally, the first determination module 602 comprises:

[0251] The first determination unit is configured to determine the application state of the battery as a storage state in a case that the historical wakeup data indicates that the number of times that the preset wakeup mode is used to wake up the BMS is greater than or equal to a first threshold value.

[0252] The second determination unit is configured to determine the application state of the battery as a cyclic use state in a case that the historical wakeup data indicates that the number of times that the preset wakeup mode is used to wake up the BMS is less than the first threshold value.

[0253] Optionally, the equalization module 603 comprises:

[0254] The first acquisition unit is configured to acquire a state of charge of each cell in N cells included in the battery in a case that the application state of the battery is the storage state, wherein N is an integer greater than 1.

[0255] The second acquisition unit is configured to acquire a residual equalization state of charge corresponding to each first cell respectively, wherein the residual equalization state of charge corresponding to the first cell is equal to a difference between the state of charge of the first cell and a state of charge of a second cell, the second cell is a cell with the lowest state of charge in the N cells, and the first cell is a cell other than the second cell in the N cells.

[0256] The first determination unit is configured to determine a residual equalization capacity corresponding to each first cell according to the residual equalization state of charge corresponding to each first cell.

[0257] The first equalization unit is configured to perform battery equalization according to the residual equalization capacity corresponding to each first cell.

[0258] Optionally, the first determination unit comprises:

[0259] The first acquisition subunit is configured to acquire a state of health (SOH) of the first cell.

[0260] The correction subunit is configured to correct the remaining equalization state corresponding to the first battery cell according to the SOH of the first battery cell, to obtain the remaining equalization capacity corresponding to the first battery cell.

[0261] Optionally, the first equalization unit can be specifically configured to:

[0262] In a case where the remaining equalization capacity corresponding to at least one first battery cell is greater than the capacity threshold, the battery is subjected to battery equalization according to the remaining equalization capacity corresponding to each first battery cell.

[0263] Optionally, the battery equalization device can further include:

[0264] The third acquisition unit is configured to, in a case where i is an integer greater than 1, acquire a first remaining equalization capacity, the first remaining equalization capacity being the remaining equalization capacity corresponding to the first battery cell in a case where the BMS is awakened i-1 times using the preset awakening manner.

[0265] The first equalization unit can be specifically configured to:

[0266] In a case where a difference between the second remaining equalization capacity and the first remaining equalization capacity is within a preset threshold range, the battery is subjected to battery equalization according to the second remaining equalization capacity, the second remaining equalization capacity being the remaining equalization capacity corresponding to the first battery cell in a case where the BMS is awakened i times using the preset awakening manner.

[0267] Optionally, the equalization module 603 includes:

[0268] The observation unit is configured to, in a case where the application state of the battery is a cyclic use state, use each of a preset M number of remaining equalization capacity observers to observe the N battery cells included in the battery during charging of the battery, to obtain M observation results corresponding to the M number of remaining equalization capacity observers, M being a positive integer.

[0269] The second equalization unit is configured to subject the battery to battery equalization according to the M observation results.

[0270] The remaining equalization capacity observer is associated with a voltage threshold, and the remaining equalization capacity observer is configured to determine the remaining equalization capacity of any battery cell in a case where the voltage of the battery cell is greater than or equal to the voltage threshold; and any observation result includes the remaining equalization capacity of at least one battery cell determined by the corresponding remaining equalization capacity observer.

[0271] Optionally, the second equalization unit includes:

[0272] The second acquisition subunit is configured to acquire a characteristic voltage.

[0273] The determining subunit is configured to determine a target observer from the M remaining equalization capacity observers according to the characteristic voltage, the target observer being a remaining equalization capacity observer associated with a voltage threshold greater than or equal to the characteristic voltage and having a minimum difference between the voltage threshold and the characteristic voltage.

[0274] The equalization subunit is configured to perform battery equalization on the battery according to the observation result corresponding to the target observer.

[0275] Optionally, the battery equalization apparatus can further include:

[0276] The fourth acquisition unit is configured to acquire N cell voltage time series curves corresponding to N cells during charging of the battery.

[0277] The second determining unit is configured to determine a third cell and a target intersection point according to the N cell voltage time series curves, the third cell being a cell with the lowest voltage after completion of charging, and the target intersection point being a last intersection point in time series between a cell voltage time series curve corresponding to the third cell and remaining cell voltage time series curves corresponding to the remaining cells.

[0278] The third determining unit is configured to determine a characteristic voltage greater than or equal to a voltage of the target intersection point.

[0279] Optionally, the battery equalization apparatus can further include:

[0280] The second acquisition module is configured to acquire a real-time charging current of the battery when a voltage of the cell is greater than or equal to a voltage threshold of the remaining equalization capacity observer.

[0281] The integration module is configured to integrate the real-time charging current according to a preset time step to obtain the remaining equalization capacity of the cell.

[0282] Optionally, the battery equalization apparatus can further include:

[0283] The upward adjustment module is configured to upwardly adjust the voltage threshold associated with each remaining equalization capacity observer when the battery is still in an application state of aging.

[0284] Optionally, the observation result corresponding to the target observer includes N third remaining equalization capacities corresponding to the N cells, the third remaining equalization capacity being the remaining equalization capacity of the cell determined by the target observer.

[0285] Correspondingly, the equalization module 603 can be specifically configured to:

[0286] In a case where at least one third remaining equalization capacity is greater than a capacity threshold, perform battery equalization on the battery according to the N third remaining equalization capacities.

[0287] Optionally, the battery equalization device can further include:

[0288] a fifth obtaining unit, configured to obtain a state of charge of the fourth battery cell and a state of charge of the fifth battery cell, the fifth battery cell being a battery cell with the lowest voltage among the N battery cells, and the fourth battery cell being a battery cell other than the fifth battery cell among the N battery cells, and the third residual equalization capacity of the fourth battery cell being greater than 0;

[0289] a fourth determining unit, configured to determine the fourth residual equalization capacity of the fourth battery cell according to a difference between the state of charge of the fourth battery cell and the state of charge of the fifth battery cell;

[0290] Correspondingly, the equalization module 603 can be specifically configured to:

[0291] in a case where the third residual equalization capacity is less than or equal to the fourth residual equalization capacity, performing battery equalization on the battery according to the third residual equalization capacity.

[0292] It should be noted that the battery equalization device is a device corresponding to the above-mentioned battery equalization method, and all implementation manners in the above-mentioned method embodiments are applicable to the embodiments of the device, and the same technical effects can also be achieved.

[0293] Figure 7 A hardware structure schematic diagram of an electronic device provided by an embodiment of the present application is shown.

[0294] The electronic device can include a processor 701 and a memory 702 having stored computer program instructions.

[0295] Specifically, the processor 701 can include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or can be configured as one or more integrated circuits that implement one or more embodiments of the present application.

[0296] The memory 702 can include a mass storage for data or instructions. By way of example and not limitation, the memory 702 can include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. Where appropriate, the memory 702 can include removable or non-removable (or fixed) media. Where appropriate, the memory 702 can be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, the memory 702 is non-volatile solid-state memory.

[0297] In particular embodiments, the memory 702 can include read-only memory (ROM), random-access memory (RAM), magnetic disk storage mediums, optical storage mediums, flash memory devices, electrical, optical, or other physical / tangible memory storage devices. Thus, in general, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software that, when executed (by one or more processors), is operable to perform the operations described with reference to the methods according to an aspect of the present disclosure.

[0298] The processor 701 implements the battery balancing method in any of the above embodiments by reading and executing computer program instructions stored in the memory 702.

[0299] In one example, the electronic device can further include a communication interface 703 and a bus 710. As shown, the processor 701, the memory 702, and the communication interface 703 are connected through the bus 710 and complete communication with each other. Figure 7

[0300] The communication interface 703 is mainly used to realize the communication between the modules, devices, units and / or equipment in the embodiments of the present application.

[0301] The bus 710 includes hardware, software, or both, that couples components of the online data traffic billing device to each other in a known manner. By way of example, and not limitation, the bus can include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an InfiniBand (IB) interconnect, a Low Pin Count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association local (VLB) bus, or another suitable bus or a combination of two or more of these. Where appropriate, the bus 710 can include one or more buses. Although the present application describes and illustrates a particular bus, the present application contemplates any suitable bus or interconnect.

[0302] In addition, in combination with the battery balancing method in the above embodiments, the embodiments of the present application can provide a computer storage medium to implement. The computer storage medium has computer program instructions stored thereon; the computer program instructions are executed by the processor to implement any of the battery balancing methods in the above embodiments.

[0303] ​It is to be understood that the application is not limited to particular configurations and processes described herein and shown in the drawings. The detailed description is not to be taken as limiting the application. In the above embodiments, several specific steps are described and illustrated in order to provide a thorough understanding of the application. However, the application can be practiced with fewer or additional steps, and in a different order. The application is to be limited only by the claims.

[0304] The functional blocks shown in the structural block diagrams above can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, and the like. When implemented in software, the elements of the application are program or code segments that are used to perform the required tasks. The program or code segments can be stored in a machine-readable medium, or transmitted through a data signal carried in a carrier wave over a transmission medium or communication link. A "machine-readable medium" includes any medium that can store or transfer information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, and the like. The code segments can be downloaded via computer networks such as the Internet, intranets, and the like.

[0305] It is also to be understood that the example embodiments described herein are based on a series of steps or apparatuses to describe some methods or systems. However, the application is not limited to the order of the steps described above, that is, the steps can be performed in the order mentioned in the embodiments, or in an order different from the embodiments, or several steps can be performed simultaneously.

[0306] The computer program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other processing devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other processing devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks. The computer program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other processing devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other processing devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks. The computer program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other processing devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other processing devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0307] The above is only a specific implementation of the present application, and those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, module and unit described above can refer to the corresponding process in the foregoing method embodiments, which will not be described here. It should be understood that the protection scope of the present application is not limited to this, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed in the present application, and these modifications or replacements should be covered within the protection scope of the present application.

Claims

1. A battery balancing method, characterized in that: include: When a battery management system BMS is awakened by a preset awakening method for the i-th time, historical awakening data of the BMS is obtained, wherein the preset awakening method is a awakening method for awakening the BMS based on a preset awakening period, and i is a positive integer; determining a battery application state based on the historical wake-up data; Performing battery balancing according to a battery balancing strategy corresponding to the application state; The determining the application state of the battery according to the historical wake-up data includes: When the historical wake-up data indicates that the number of consecutive times the BMS is awakened using the preset wake-up method is greater than or equal to a first threshold, determining the application state of the battery as an inventory state; When the historical wake-up data indicates that the number of consecutive times the BMS is awakened using the preset wake-up method is less than a first threshold, the application state of the battery is determined to be a cyclic use state.

2. The method according to claim 1, characterized in that The performing battery balancing according to the battery balancing strategy corresponding to the application state includes: When the application state of the battery is an inventory state, obtaining the state of charge of each of N battery cells included in the battery, where N is an integer greater than 1; Obtaining a remaining balanced state of charge corresponding to each first battery cell, respectively, where the remaining balanced state of charge corresponding to the first battery cell is equal to a difference between the state of charge of the first battery cell and the state of charge of a second battery cell, where the second battery cell is the battery cell with the lowest state of charge among the N battery cells, and the first battery cell is the battery cell other than the second battery cell among the N battery cells; determining a remaining balanced capacity corresponding to each of the first battery cells according to a remaining balanced state of charge corresponding to each of the first battery cells; Battery balancing is performed according to the remaining balancing capacity corresponding to each of the first battery cells.

3. The method according to claim 2, characterized in that The determining, according to the remaining balanced state of charge corresponding to each of the first battery cells, the remaining balanced capacity corresponding to each of the first battery cells includes: Obtaining the state of health (SOH) of the first battery cell; According to the SOH of the first battery cell, the remaining balanced state of charge corresponding to the first battery cell is corrected to obtain the remaining balanced capacity corresponding to the first battery cell.

4. The method according to claim 2, characterized in that The performing battery balancing according to the remaining balancing capacity corresponding to each of the first battery cells includes: When the remaining balancing capacity corresponding to at least one of the first battery cells is greater than a capacity threshold, the battery is balanced according to the remaining balancing capacity corresponding to each of the first battery cells.

5. The method according to claim 4, characterized in that Before performing battery balancing on the battery according to the remaining balancing capacity corresponding to each of the first battery cells, the method further includes: When i is an integer greater than 1, a first remaining balancing capacity is obtained, where the first remaining balancing capacity is the remaining balancing capacity corresponding to the first battery cell when the BMS is awakened by the preset awakening method for the (i-1)th time; The performing battery balancing on the battery according to the remaining balancing capacity corresponding to each of the first battery cells includes: When a difference between a second remaining balancing capacity and the first remaining balancing capacity is within a preset threshold range, battery balancing is performed on the battery according to the second remaining balancing capacity, where the second remaining balancing capacity is the remaining balancing capacity corresponding to the first battery cell when the BMS is awakened by the preset awakening method i times.

6. The method according to claim 1, characterized in that The performing battery balancing according to the battery balancing strategy corresponding to the application state includes: When the battery is in a cycle-use state, during charging of the battery, each of M preset remaining balancing capacity observers is used to observe N battery cells included in the battery, thereby obtaining M observation results corresponding to the M remaining balancing capacity observers, where M is a positive integer. Performing battery balancing on the battery according to the M observation results; The remaining balancing capacity observer is associated with a voltage threshold, and is used to determine the remaining balancing capacity of any of the battery cells when the voltage of any of the battery cells is greater than or equal to the voltage threshold; and any of the observation results includes the remaining balancing capacity of at least one of the battery cells determined by the corresponding remaining balancing capacity observer.

7. The method according to claim 6, characterized in that The performing battery balancing on the battery according to the M observation results includes: Obtain characteristic voltage; determining a target observer from the M remaining balancing capacity observers according to the characteristic voltage, the target observer being a remaining balancing capacity observer whose associated voltage threshold is greater than or equal to the characteristic voltage and whose associated voltage threshold has the smallest difference with the characteristic voltage; The battery is balanced according to the observation result corresponding to the target observer.

8. The method according to claim 7, characterized in that Before obtaining the characteristic voltage, the method further includes: Obtaining N battery cell voltage timing curves corresponding to the N battery cells during charging of the battery; Determine, according to the N battery cell voltage timing curves, a third battery cell and a target intersection point, where the third battery cell is the battery cell with the lowest voltage after charging is completed, and the target intersection point is the last intersection point between the battery cell voltage timing curve corresponding to the third battery cell and the voltage timing curves of the remaining battery cells, where the voltage timing curves of the remaining battery cells are the battery cell voltage timing curves corresponding to the battery cells other than the third battery cell among the N battery cells; The characteristic voltage is determined based on the voltage of the target intersection, and the characteristic voltage is greater than or equal to the voltage of the target intersection.

9. The method according to claim 6, characterized in that The remaining balancing capacity observer determines the remaining balancing capacity of any of the battery cells when the voltage of any of the battery cells is greater than or equal to the voltage threshold, including: The remaining balanced capacity observer obtains the real-time charging current of the battery when the voltage of the battery cell is greater than or equal to the voltage threshold; The real-time charging current is integrated according to a preset time step to obtain the remaining balanced capacity of the battery cell.

10. The method according to claim 6, characterized in that Before using each of the preset M remaining balanced capacity observers to observe the N battery cells included in the battery, the method further includes: When the battery is still in an aging application state, the voltage threshold associated with each of the remaining balanced capacity observers is increased.

11. The method according to claim 7, characterized in that The observation result corresponding to the target observer includes N third remaining balancing capacities corresponding to N battery cells, where the third remaining balancing capacities are the remaining balancing capacities of the battery cells determined by the target observer; The performing battery balancing on the battery according to the observation result corresponding to the target observer includes: In a case where at least one of the third remaining balancing capacities is greater than a capacity threshold, battery balancing is performed on the batteries according to the N third remaining balancing capacities.

12. The method according to claim 11, characterized in that Before performing battery balancing on the batteries according to the N third remaining balancing capacities, the method further includes: Obtaining a state of charge (SOC) of a fourth battery cell and a state of charge (SOC) of a fifth battery cell, where the fifth battery cell is a battery cell with the lowest voltage among the N battery cells, the fourth battery cell is a battery cell other than the fifth battery cell among the N battery cells, and a third remaining equalization capacity of the fourth battery cell is greater than 0; determining a fourth remaining equalization capacity of the fourth battery cell according to a difference between the state of charge of the fourth battery cell and the state of charge of the fifth battery cell; The performing battery balancing on the battery according to the N third remaining balancing capacities includes: When the third remaining balancing capacity is less than or equal to the fourth remaining balancing capacity, the batteries are balanced according to the third remaining balancing capacity.

13. A battery balancing device, characterized in that: The device comprises: A first acquisition module is configured to acquire historical wake-up data of a battery management system (BMS) when a preset wake-up method is used to wake up the BMS for the i-th time, wherein the preset wake-up method is a wake-up method for waking up the BMS based on a preset wake-up period, and i is a positive integer; A first determining module, configured to determine a battery application state based on the historical wake-up data; a balancing module, configured to perform battery balancing according to a battery balancing strategy corresponding to the application state; The first determining module includes: a first determining unit, configured to determine the application state of the battery as an inventory state when the historical wake-up data indicates that a consecutive number of times the BMS is awakened using the preset wake-up method is greater than or equal to a first threshold; The second determining unit is configured to determine the application state of the battery as a cyclic use state when the historical wake-up data indicates that the number of consecutive times the BMS is awakened by using the preset wake-up method is less than a first threshold.

14. An electronic device, characterized in that: The device includes: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, the battery balancing method according to any one of claims 1 to 12 is implemented.

15. A computer program product, characterized in that When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device is caused to perform the battery balancing method according to any one of claims 1 to 12.

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