Battery pack cell equalization control method, terminal and storage medium

Abstract

The application provides a battery pack single cell equalization control method, a terminal and a storage medium. The battery pack single cell equalization control method comprises the following steps: obtaining the cell states of each cell in a battery pack; when the working condition of the battery pack is a static working condition, calculating the single cell residual capacity of each cell based on the cell states of each cell, judging whether the first preset equalization starting condition corresponding to the static working condition is met based on the single cell residual capacity and the cell states, and determining the cell to be equalized based on the single cell residual capacity if the first preset equalization starting condition is met; when the working condition of the battery pack is a constant current working condition, determining the battery state of charge interval in which the battery pack is located based on the cell states of each cell, determining the cell to be equalized based on the second preset equalization starting condition corresponding to the battery state of charge interval, and performing equalization processing on the cell to be equalized until a preset equalization stopping condition is met, and then stopping the equalization processing, so that the adaptability and reliability of the battery pack single cell equalization under different working conditions can be realized.

Description

Technical Field

[0001] This invention relates to the field of battery management technology, and in particular to a method, terminal and storage medium for equalizing individual cells in a battery pack. Background Technology

[0002] With the rapid development of electric ships, battery management systems (BMS) play a crucial role in ensuring the safe and efficient operation of ship power batteries. Electric ships typically use lithium-ion battery packs composed of multiple cells connected in series or parallel as their power source. However, due to differences in manufacturing, usage environment, and aging process, the voltage, internal resistance, and state of charge of each cell can be inconsistent. If this inconsistency is not controlled, it will lead to overcharging or over-discharging of some cells, thereby reducing the overall capacity of the battery pack, shortening its service life, and even causing safety accidents. Especially in marine applications, environmental factors such as vibration, humidity, temperature fluctuations, and long-term high-load operation can exacerbate the problem of cell inconsistency.

[0003] Currently, there are two main implementation paths for marine BMS equalization technology: one is passive equalization, such as discharging through resistors. This method is inefficient, wastes energy as heat, is unsuitable for high-power marine applications, and may exacerbate the thermal management burden of the battery due to heat generation. The other is active equalization, such as capacitive or inductive equalization. Although it is more efficient, the circuitry is complex and costly, and its reliability is insufficient in ship vibration and humid environments, making it prone to failure. More importantly, existing equalization strategies generally rely on fixed thresholds for start-stop judgments, which cannot dynamically adapt to changes in cell status (such as SOC, temperature, and health status). This results in lag in equalization actions, insufficient control precision, and the potential for additional power consumption during high-load operation, which may interfere with the battery's range. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a battery pack cell equalization control method, terminal and storage medium that can achieve the adaptability and reliability of battery pack cell equalization under different operating conditions.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for equalizing individual cells in a battery pack, comprising: Obtain the cell status of each cell in the battery pack; When the battery pack is in a static operating condition, the remaining capacity of each cell is calculated based on the cell status of each cell. Based on the remaining capacity of each cell and the cell status, it is determined whether the first preset equalization start condition corresponding to the static operating condition is met. If it is met, the cell to be equalized is determined based on the remaining capacity of the cell. When the battery pack is in constant current mode, the battery state of charge interval of the battery pack is determined based on the cell state of each cell, and the cell to be balanced is determined based on the second preset equalization start condition corresponding to the battery state of charge interval. The cells to be balanced are subjected to balancing processing until the preset balancing stop condition is met, at which point the balancing process is stopped.

[0006] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is as follows: A battery pack cell equalization control terminal includes a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the computer program to implement the various steps of the aforementioned battery pack cell equalization control method.

[0007] To solve the above-mentioned technical problems, another technical solution adopted by the present invention is as follows: A computer storage medium storing a computer program, which is executed by a processor to implement the various steps of the above-described battery pack cell equalization control method.

[0008] The beneficial effects of this invention are as follows: By acquiring the cell status of each cell in the battery pack, a real-time data foundation is provided for subsequent adaptive balancing control under various operating conditions; under static operating conditions, the remaining capacity of each cell is calculated, and the cell status is combined to determine whether the first preset balancing start condition corresponding to the operating condition is met. When met, the cell to be balanced is determined based on the remaining capacity of the cell. Under constant current operating conditions, the battery charge state interval of the battery pack is determined based on the cell status, and the second preset balancing start condition corresponding to the interval is called to determine the cell to be balanced, thereby achieving adaptive matching of balancing triggering strategies under different operating conditions and enhancing the targeted balancing response under dynamic operating conditions; balancing processing is performed on the cell to be balanced until the preset balancing stop condition is met, thus avoiding over-balancing or under-balancing, ensuring that the balancing process converges to the target state, effectively guaranteeing the reliability of battery balancing, and solving the capacity decay and safety problems caused by inconsistent cell voltages in the battery pack. Attached Figure Description

[0009] Figure 1 This is a flowchart of a battery pack cell equalization control method according to an embodiment of the present invention; Figure 2 This is an example diagram of the OCV-SOC curve and its differential curve in an embodiment of the present invention; Figure 3 This is an example diagram of cell data sampling and recording in an embodiment of the present invention; Figure 4 This is an example diagram illustrating the cell reference voltage-capacity-SOC mapping relationship in an embodiment of the present invention; Figure 5 This is a schematic diagram of a battery pack cell equalization control terminal according to an embodiment of the present invention. Detailed Implementation

[0010] Definitions:

[0011] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0012] In existing technologies, marine BMS balancing technologies mainly employ two methods: passive balancing and active balancing. Passive balancing dissipates excess energy as heat through resistor discharge, but this method is inefficient, generates concentrated heat, and can easily exacerbate the thermal management burden on the battery. Active balancing, using capacitors or inductors, is more efficient, but its circuitry is complex and costly, and its reliability is insufficient in ship vibration and humid environments, making it prone to failure. Furthermore, existing balancing strategies mostly rely on fixed thresholds for start-stop judgments, lacking the ability to adapt to dynamic parameters such as cell state of charge, health status, and temperature. This results in lag in balancing actions, insufficient accuracy, and the potential for additional power consumption during high-load operation, which can affect the ship's range.

[0013] To at least address the aforementioned issues, the cell status of each cell in the battery pack is obtained. Under static conditions, the remaining capacity of each individual cell is calculated and combined with the cell status to determine whether the first preset equalization start condition corresponding to that condition is met. If met, the cell to be equalized is determined based on the remaining capacity of the individual cell. Under constant current conditions, the battery pack's state of charge range is determined based on the cell status, and the second preset equalization start condition corresponding to that range is invoked to determine the cell to be equalized. Equalization processing is performed on the cells to be equalized until the preset equalization stop condition is met, at which point the process terminates. In this way, adaptive matching of equalization triggering strategies under different operating conditions can be achieved, effectively improving equalization efficiency and reliability, and solving the capacity decay and safety issues caused by inconsistent cell voltages in the battery pack.

[0014] The following describes in detail a battery pack cell equalization control method of the present invention. Please refer to [link / reference]. Figure 1 The method 100 includes steps 101 to 104: Step 101: Obtain the cell status of each cell in the battery pack.

[0015] Specifically, taking the battery pack of an electric boat as an example, this battery pack contains multiple cells, temperature sensors, current sensors, relays, and wiring harnesses. After the BMS (Battery Management System, which interacts with the main control system of the electric boat via CAN or RS485 communication) is powered on, it continuously collects the voltage, current, and temperature data of each cell, thereby estimating the state of charge, battery health, and charge / discharge power of each cell, providing a real-time data basis for subsequent adaptive balancing control under operating conditions.

[0016] Step 102: When the battery pack is in a static operating condition, calculate the remaining capacity of each cell based on the cell state of each cell, and determine whether the first preset equalization start condition corresponding to the static operating condition is met based on the remaining capacity of the cell and the cell state. If it is met, determine the cell to be equalized based on the remaining capacity of the cell.

[0017] Specifically, if the battery pack current is consistently <1A for 30 minutes, and the battery state of charge (SOC) is <30% or >90%, the battery pack is considered to be in a static state. Based on the SOC of each cell, the remaining capacity of each individual cell is calculated. The range between the remaining capacity and the cell state is then calculated. Based on this, it is determined whether the first preset equalization start condition for the static state is met. If met, the cells to be equalized are identified based on their remaining capacity; that is, cells with higher remaining capacity are equalized. This method comprehensively considers the range between the remaining capacity and the cell state to trigger equalization and accurately locates the cells to be equalized, effectively improving the accuracy and targeting of the equalization start-up.

[0018] Step 103: When the battery pack is in constant current condition, the battery state of charge interval of the battery pack is determined based on the cell state of each cell, and the cells to be balanced are determined based on the second preset balancing start condition corresponding to the state of charge interval.

[0019] Specifically, when the battery pack operates under constant current conditions, the average state of charge (SOC) of the battery pack is calculated based on the SOC of each cell, thereby determining the SOC range in which the battery pack is located. The cells to be balanced are then determined according to the second preset balancing start condition corresponding to this SOC range. In this way, accurate identification and targeted balancing of cell inconsistencies can be achieved across the entire constant current operating range, improving the adaptability and accuracy of the balancing strategy.

[0020] Step 104: Perform balancing processing on the cells to be balanced until the preset balancing stop condition is met, and then stop the balancing process.

[0021] Specifically, after identifying the cells to be balanced, a balancing process is performed on them. This involves an balancing circuit (using active balancing technology, such as energy transfer based on capacitors or inductors, supporting bidirectional energy flow and improving balancing efficiency) to perform energy transfer and monitor in real time the remaining capacity difference between all cells in the battery pack and the balanced capacity of the cell to be balanced. The balancing process stops when a preset balancing stop condition is met. This method enables closed-loop dynamic control of the balancing process, avoiding over-balancing or under-balancing, effectively ensuring battery balancing reliability, and resolving capacity decay and safety issues caused by inconsistent cell voltages within the battery pack.

[0022] In one embodiment of the present invention, step 102 includes steps 1021 and 1022, including: Step 1021: Determine the temperature coefficient based on the temperature, and calculate the remaining capacity of the corresponding cell based on the preset rated capacity, the battery health status, the battery state of charge, and the temperature coefficient: Remaining capacity of cell = Preset rated capacity × Battery health status × (1 - Battery state of charge) × Temperature coefficient.

[0023] Specifically, the cell status includes the battery state of charge (SOC), battery health status, and temperature. The remaining capacity of each cell is calculated using the following formula: Remaining Capacity per Cell = Preset Rated Capacity × Battery Health Status × (1 - Battery SOC) × Temperature Coefficient. This method reduces estimation errors caused by relying solely on voltage or SOC lookup tables, making the capacity calculation closer to the actual usable capacity of the cell. It provides a more accurate and reliable basis for determining the balancing trigger under static conditions, ensuring the effectiveness and safety of the balancing strategy.

[0024] Step 1022: Calculate the capacity difference based on the remaining capacity of each cell, calculate the battery state of charge difference based on the battery state of charge of each cell, and determine whether the first preset equalization start-up condition corresponding to the static working condition is met based on the capacity difference and the battery state of charge difference.

[0025] Specifically, the maximum and minimum remaining capacities of each individual cell are obtained, and the capacity difference between them is calculated. The maximum and minimum states of charge (SOC) of each cell are also obtained, and the SOC difference between them is calculated. When the capacity difference exceeds a first preset capacity difference threshold, or the SOC difference exceeds a first preset SOC difference threshold, or both the capacity difference and SOC difference exceed a second preset capacity difference threshold, the first preset equalization start-up condition corresponding to the static operating condition is deemed met. Preferably, the first preset capacity difference threshold is 10% of the preset rated capacity, the second preset capacity difference threshold is 5% of the preset rated capacity, the first preset SOC difference threshold is 10%, and the second preset SOC difference threshold is 5%. This method enables equalization triggering through a comprehensive multi-threshold determination based on both capacity and SOC dimensions, balancing independent and collaborative triggering, improving start-up accuracy and sensitivity, avoiding missed or false triggers, and ensuring the effectiveness of the equalization strategy.

[0026] In one embodiment of the present invention, step 103 includes steps 1031 to 1033: Step 1031: Calculate the average state of charge (SOC) based on the SOC of each cell, and determine the SOC range of the battery pack according to the average SOC.

[0027] Specifically, please refer to Figure 2 The first and second battery states of charge (SOCs) are set according to a preset OCV-SOC curve. The first SOC is preferably 10%, and the second SOC is preferably 90%. An average SOC is calculated based on the SOC of each cell. When the average SOC is less than the first SOC, the battery pack is considered to be in the peak of the charge / discharge cycle; when the average SOC is greater than the second SOC, the battery pack is considered to be in the bottom of the charge / discharge cycle; when the average SOC is greater than or equal to the first SOC and less than or equal to the second SOC, the battery pack is considered to be in a plateau phase. This method quantifies and standardizes the range determination, providing clear trigger boundaries for differentiated balancing strategies and improving the targeting and reliability of the balancing determination.

[0028] Step 1032: Obtain the voltage of each cell, and calculate the slope of the voltage-state-of-charge curve for each cell based on the voltage and the state of charge of the battery.

[0029] Specifically, please refer to Figure 3It can acquire the voltage VOL of each cell and its corresponding state of charge SOC in real time, and calculate the slope of the voltage-state of charge curve (dV / dSOC) of each cell at the current moment based on the voltage and the state of charge, so as to provide reliable data support for the start of the differentiated balancing strategy under constant current conditions.

[0030] Step 1033: When the battery state of charge interval is at the top of the charge / discharge cycle or at the bottom of the charge / discharge cycle, determine the cells to be balanced based on the slope of the voltage-battery state of charge curve; when the battery state of charge interval is a plateau period, obtain the preset peak value corresponding to the plateau period, obtain the time when the slope of the voltage-battery state of charge curve of each cell reaches the preset peak value, and determine the cells to be balanced based on the charge / discharge state of the battery pack and the time when the slope of the voltage-battery state of charge curve of each cell reaches the preset peak value.

[0031] Specifically, please refer to Figure 2 and Figure 4 When the battery pack is at the peak or trough of charge / discharge, the cell with the largest slope of the voltage-state-of-charge curve is selected as the cell to be balanced: at the peak of charge / discharge, the largest slope indicates that the cell has the highest relative SOC and needs to be balanced; at the trough of charge / discharge, the largest slope indicates that the cell has the lowest relative SOC and needs to be balanced first. When the battery pack is in a plateau phase, the preset peak value corresponding to the plateau phase is determined according to the preset dOCV / dSOC curve: based on Figure 4 The voltage-capacity-state-of-charge mapping relationship shown is a preset benchmark characteristic data of this cell, which is used to construct, as follows: Figure 2 The preset OCV-SOC curve and its differential curve (dOCV / dSOC curve) are shown; typically, the plateau period will have two peaks (e.g., Figure 2The two points (SOC=25% and SOC=60%) are used. Since the voltage change rate before and after the peak SOC=60% is small and easier to judge, the second peak (SOC=60%) is selected as the preset peak. The time when the slope of the voltage-battery state of charge curve of each cell reaches the preset peak is obtained. Based on the charging and discharging state of the battery pack and the time when the slope of the voltage-battery state of charge curve of each cell reaches the preset peak, the cells to be balanced are determined: the cell that reaches the peak first during charging has the highest capacity and is marked as the cell to be balanced; the cell that reaches the peak last during discharging has the highest capacity and is marked as the cell to be balanced. Furthermore, the time when the preset peak value is reached first is recorded as t(1), and the time when the remaining cells reach the preset peak value is recorded as t(n). According to the formula: Capacity difference value = Current × (t(1) - t(n)), the capacity difference of each cell relative to the cell that reaches the preset peak value first is estimated. This capacity difference value can be used to verify the rationality of confirming the cells to be balanced based on time sorting: if the capacity difference value is large, it means that the capacity of the marked object is obviously too high, and the necessity of balancing is sufficient; if the capacity difference value is small, it means that the capacity difference of each cell is small, and balancing can be postponed to avoid ineffective balancing. In this way, the cells to be balanced can be quickly locked by time sorting during the plateau period, and the effectiveness of marking can be verified by estimating the capacity difference, avoiding mismarking caused by measurement error or time synchronization deviation, and improving the accuracy and robustness of the plateau period balancing judgment.

[0032] In one embodiment of the present invention, step 104 includes steps 1041 and 1042: Step 1041: Monitor in real time the difference in remaining capacity between all cells in the battery pack and the balanced capacity value of the cells to be balanced. When the difference in remaining capacity between cells is less than a third preset capacity difference threshold or the balanced capacity value reaches a preset balanced capacity threshold, determine that the preset balanced stop condition is met.

[0033] Specifically, during the equalization process, the remaining capacity of each individual cell is calculated in real time. The difference between the maximum and minimum remaining capacities of each cell is used to calculate the range of remaining capacities per cell. The remaining capacity of the cell to be equalized before equalization is compared with its current remaining capacity to calculate the equalized capacity value. When the range of remaining capacities per cell is less than a third preset capacity difference threshold, or when the equalized capacity value reaches a preset equalization capacity threshold, the preset equalization stop condition is met, and the equalization process is stopped. The third preset capacity difference threshold is preferably 2% of the preset rated capacity, and the preset equalization capacity threshold is preferably 1% of the preset rated capacity. This method achieves dynamic control of the equalization process, avoiding over-equalization or under-equalization.

[0034] Step 1042: Monitor the cell parameters during the equalization process. If any abnormality is detected in the cell parameters, immediately stop the equalization process and issue an alarm.

[0035] Specifically, throughout the equalization process, key cell parameters such as temperature, voltage, and current of each cell are continuously monitored simultaneously. If any abnormalities are detected, such as excessively high temperature or sudden voltage changes, the equalization process is immediately terminated, and an alarm is reported. This method ensures that the equalization process always operates within safe boundaries, preventing safety accidents caused by cell overheating or abnormal voltage, and guaranteeing the operational safety of the ship's battery system.

[0036] In one embodiment of the present invention, after equalization is completed, the cell status data, such as the state of charge of each cell, is updated, and key information such as the equalization execution status, equalization duration, and cumulative equalization capacity are stored. Simultaneously, this information is reported to the ship's main control system via a communication interface. To minimize interference with the normal operation of the ship's power system during the equalization process and avoid impacting range under high-load conditions due to additional power consumption introduced by equalization, a power-down equalization strategy is adopted: the BMS controls the high-voltage relay to disconnect and remains stationary for 30 minutes to eliminate the influence of polarization voltage; the open-circuit voltage method is used to correct the state of charge of each cell, obtain the current state of charge of each cell, recalculate the remaining capacity of each cell, and mark the cells to be equalized for equalization processing. This effectively avoids the equalization power being superimposed on the operating load of the power system, ensuring that the ship's navigation range is not affected. Furthermore, the BMS can automatically perform equalization whether the ship is running or moored, and supports timed or event-triggered modes to flexibly adapt to the equalization needs under different ship operating conditions, minimizing the impact on the ship's power system.

[0037] In summary, this invention provides a battery pack cell equalization control method. By acquiring the cell state of each cell in the battery pack, it provides a real-time data foundation for subsequent adaptive equalization control under various operating conditions. Under static conditions, the remaining capacity of each cell is calculated, and the cell state is used to determine whether the first preset equalization start condition corresponding to this operating condition is met. When the condition is met, the cell to be equalized is determined based on the remaining capacity of the cell. Under constant current conditions, the battery state of charge interval of the battery pack is determined based on the cell state, and the second preset equalization start condition corresponding to this interval is called to determine the cell to be equalized. This achieves adaptive matching of equalization triggering strategies under different operating conditions, enhancing the specificity of equalization response under dynamic operating conditions. The equalization process is performed on the cell to be equalized until the preset equalization stop condition is met, thus avoiding over-equalization or under-equalization and ensuring that the equalization process converges to the target state. This effectively guarantees the reliability of battery equalization and solves the capacity decay and safety problems caused by inconsistent cell voltages in the battery pack.

[0038] The present invention has the following beneficial effects: 1. Improve overall battery pack performance and lifespan: Through efficient equalization control, reduce capacity decay caused by cell inconsistency, extend battery pack lifespan, and reduce maintenance costs.

[0039] 2. Enhance ship operation safety: Intelligent balancing strategy prevents overcharging or over-discharging of battery cells, reduces the risk of thermal runaway, and adapts to harsh ship environments.

[0040] 3. Improved energy efficiency and environmental friendliness: Active balancing reduces energy waste, enhances the range of electric ships, and meets green ship standards.

[0041] 4. Optimize user experience: The balancing process is seamlessly integrated into ship operation, avoiding balancing interference with normal operation and ensuring the stability and reliability of the power system.

[0042] Please refer to Figure 5 The present invention also provides a battery pack cell equalization control terminal 200, including a memory 201, a processor 202, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the various steps of a battery pack cell equalization control method as described above.

[0043] The present invention also provides a computer storage medium storing a computer program, which is executed by a processor to implement the various steps of the above-described battery pack cell equalization control method.

[0044] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for equalizing the operation of individual cells in a battery pack, characterized in that, include: Obtain the cell status of each cell in the battery pack; When the battery pack is in a static operating condition, the remaining capacity of each cell is calculated based on the cell status of each cell. Based on the remaining capacity of each cell and the cell status, it is determined whether the first preset equalization start condition corresponding to the static operating condition is met. If it is met, the cell to be equalized is determined based on the remaining capacity of the cell. When the battery pack is in constant current condition, the battery state of charge interval of the battery pack is determined based on the cell state of each cell, and the cell to be balanced is determined based on the second preset balancing start condition corresponding to the battery state of charge interval. The cells to be balanced are subjected to balancing processing until the preset balancing stop condition is met, at which point the balancing process is stopped.

2. The battery pack cell equalization control method according to claim 1, characterized in that, The remaining capacity of each individual battery cell is calculated based on its cell state, including: The cell status includes the battery state of charge, battery health status, and temperature; Based on the temperature, a temperature coefficient is determined. Based on the preset rated capacity, the battery health status, the battery state of charge, and the temperature coefficient, the remaining capacity of the corresponding cell is calculated. Cell remaining capacity = preset rated capacity × battery health status × (1 - battery state of charge) × temperature coefficient.

3. The battery pack cell equalization control method according to claim 1, characterized in that, Determining whether the first preset equalization start-up condition corresponding to the static operating condition is met based on the remaining capacity of the individual cell and the cell status includes: Obtain the maximum and minimum remaining capacity of each cell from the remaining capacity of each cell, and calculate the capacity difference between the maximum and minimum remaining capacity of each cell. The maximum and minimum states of charge (SOC) of the battery cells are obtained from the cell states of each cell, and the SOC difference between the maximum and minimum SOC is calculated. When the capacity difference exceeds a first preset capacity difference threshold, or the battery state of charge difference exceeds a first preset battery state of charge difference threshold, or the capacity difference exceeds a second preset capacity difference threshold and the battery state of charge difference exceeds a second preset battery state of charge difference threshold, it is determined that the first preset equalization start-up condition corresponding to the static working condition is met, wherein the first preset capacity difference threshold is greater than the second preset capacity difference threshold, and the first preset battery state of charge difference threshold is greater than the second preset battery state of charge difference threshold.

4. The battery pack cell equalization control method according to claim 2, characterized in that, Determining the battery pack's state of charge range based on the cell states of each cell includes: The average state of charge (SOC) is calculated based on the SOC of each cell. When the average state of charge of the battery is less than the first state of charge of the battery, the battery state of charge range in which the battery pack is located is determined to be the top of the charge / discharge range. When the average state of charge of the battery is greater than the second state of charge of the battery, the battery state of charge range in which the battery pack is located is determined to be the bottom of the charge / discharge range. When the average battery state of charge is greater than or equal to the first battery state of charge and the average battery state of charge is less than or equal to the second battery state of charge, the battery state of charge interval of the battery pack is determined to be a plateau period.

5. The battery pack cell equalization control method according to claim 4, characterized in that, The cells to be balanced are determined based on the second preset balancing start conditions corresponding to the battery state of charge range, including: Obtain the voltage of each cell, and calculate the slope of the voltage-state-of-charge curve for each cell based on the voltage and the state of charge of the battery. When the battery state of charge range is at the top of the charge / discharge cycle or at the bottom of the charge / discharge cycle, the cells to be balanced are determined based on the slope of the voltage-battery state of charge curve.

6. The battery pack cell equalization control method according to claim 5, characterized in that, The method for determining the cells to be balanced based on the second preset balancing start conditions corresponding to the battery state of charge range also includes: When the battery state of charge range is a plateau period, a preset peak value corresponding to the plateau period is obtained, and the time when the slope of the voltage-battery state of charge curve of each cell reaches the preset peak value is obtained. Based on the charging and discharging state of the battery pack and the time when the slope of the voltage-battery state of charge curve of each cell reaches the preset peak value, the cells to be balanced are determined.

7. The battery pack cell equalization control method according to claim 3, characterized in that, The cells to be balanced are subjected to balancing processing until a preset balancing stop condition is met, including: The remaining capacity difference between all cells in the battery pack and the balanced capacity value of the cells to be balanced are monitored in real time. When the remaining capacity difference between cells is less than a third preset capacity difference threshold or the balanced capacity value reaches a preset balancing capacity threshold, the preset balancing stop condition is determined to be met. The second preset capacity difference threshold is greater than the third preset capacity difference threshold, and the third preset capacity difference threshold is greater than the preset balancing capacity threshold.

8. The battery pack cell equalization control method according to claim 1, characterized in that, The balancing process for the cells to be balanced further includes: Monitor the cell parameters during the equalization process. If any abnormality is detected in the cell parameters, immediately stop the equalization process and issue an alarm.

9. A battery pack cell equalization control terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements each step of the battery pack cell equalization control method according to any one of claims 1 to 8.

10. A computer storage medium storing a computer program, characterized in that, The computer program is executed by a processor to implement the steps of the battery pack cell equalization control method according to any one of claims 1 to 8.

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