Battery management method and system, battery equipment and electric device

Abstract

The battery management method comprises the following steps: acquiring a battery capacity, wherein the battery capacity comprises a battery full charge capacity or a battery full discharge capacity; in response to the fact that the battery capacity is smaller than or equal to a first capacity threshold value, correcting the charging current parameter value to reduce the charging current parameter value to a first charging current parameter value; the battery capacity is larger than a second capacity threshold value in response to the fact that the battery is charged to the full charging state according to the first charging current parameter value, and the second capacity threshold value is larger than the first capacity threshold value.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of battery technology, and in particular to a battery management method, system, battery equipment and power-consuming device. Background Art

[0002] The charging SOP (State of Power) is used to describe the maximum charging power or maximum charging current that a battery can safely accept during charging. The charging SOP in the prior art is solidified as a fixed parameter, usually set based on the state of the battery when it leaves the factory. Summary of the invention

[0003] The embodiments of the present application provide a battery management method, system, battery equipment and power-consuming device, which can increase battery capacity, delay battery aging process and increase battery service life.

[0004] In a first aspect, an embodiment of the present application provides a battery management method, comprising: obtaining a battery capacity, wherein the battery capacity includes a battery full charge capacity or a battery full discharge capacity; in response to the battery capacity being less than or equal to a first capacity threshold, correcting a charging current parameter value to reduce the charging current parameter value to a first charging current parameter value. When the battery capacity is less than or equal to the first capacity threshold, it reflects that the battery has aged to a certain extent, and the charging current parameter value is reduced to the first charging current parameter value. The charging current parameter value includes a maximum allowable charging current or a maximum allowable charging rate.

[0005] The battery is charged according to the first charging current parameter value, so that the battery capacity increases to exceed the second capacity threshold, and the second capacity threshold is greater than the first capacity threshold. After the battery ages, the charging current parameter value is reduced so that the battery is charged with a smaller charging current, which can provide more charging time for cells with a higher degree of aging, so that they are close to fully charged, thereby increasing the overall charging capacity. Reducing the charging speed also helps to balance the voltage between cells, thereby improving the performance and consistency of the entire battery. Moreover, using a smaller and more appropriate charging current after the battery ages can reduce stress accumulation and slow down the aging process.

[0006] In some of the embodiments, obtaining the full charge capacity of the battery includes: calculating the battery charge capacity in response to a single charge of the battery from a fully discharged state to a fully charged state; or calculating the battery charge capacity in response to a cumulative charge of the battery from a fully discharged state to a fully charged state.

[0007] In other embodiments, obtaining the full discharge capacity of the battery includes: calculating the discharged capacity of the battery in response to a single discharge of the battery from a fully charged state to a fully discharged state; or calculating the discharged capacity of the battery in response to a cumulative discharge of the battery from a fully charged state to a fully discharged state.

[0008] In some embodiments, when the battery capacity is less than or equal to the first capacity threshold, the charging current parameter value is gradually reduced with a first step length until it is reduced to a value greater than the second capacity threshold when full charging is completed based on the updated charging current parameter value. By correcting the original charging current parameter value by gradually decreasing the step length, a better charging current parameter value matching the current battery state is found, thereby optimizing the capacity performance after full charging, delaying battery aging, and increasing the battery life.

[0009] In some embodiments, the charging current parameter value is corrected based on the full charge capacity change of the battery, including:

[0010] S1: Subtract the first step length from the charging current parameter value to update the charging current parameter value;

[0011] S2: In response to the battery being charged to a fully charged state based on the updated charging current parameter value, calculating the full charge capacity Q1 of the battery;

[0012] The battery is charged to a fully charged state based on the updated charging current parameter value, including: the battery is charged from a fully discharged state to a fully charged state once, or the battery is cumulatively charged from a fully discharged state to a fully charged state;

[0013] S3:

[0014] S3.1 In response to the full charge capacity Q1 being greater than the full charge capacity Q2 when the battery is charged to a fully charged state, and the full charge capacity Q1 being less than or equal to the second capacity threshold, jump to S1 and execute steps S1 and S2;

[0015] S3.2 In response to the full charge capacity Q1 being greater than the full charge capacity Q2 when the battery is charged to a fully charged state, and the full charge capacity Q1 being greater than the second capacity threshold, completing the correction of the charging current parameter value;

[0016] The full charge capacity Q2 is defined as the full charge capacity of the battery when the battery is charged to a fully charged state based on the charging current parameter value before the update.

[0017] In some other embodiments, the charging current parameter value is corrected based on the full discharge capacity change of the battery, including:

[0018] A1: Subtract the first step length from the charging current parameter value to update the charging current parameter value;

[0019] A2: In response to the battery being charged to a fully charged state and discharged to a fully discharged state based on the updated charging current parameter value, calculating the full discharge capacity Q3 of the battery;

[0020] The battery discharges from a fully charged state to a fully discharged state, including: the battery discharges from a fully charged state to a fully discharged state once, or the battery discharges from a fully charged state to a fully discharged state cumulatively;

[0021] A3:

[0022] A3.1 In response to the full discharge capacity Q3 being greater than the full discharge capacity Q4 when the battery is discharged from a fully charged state to a fully discharged state, and the full discharge capacity Q3 being less than or equal to the second capacity threshold, jump to A1 and execute steps A1 and A2;

[0023] A3.2 completes the correction of the charging current parameter value in response to the full discharge capacity Q3 being greater than the full discharge capacity Q4 when the battery is discharged from a fully charged state to a fully discharged state, and the full discharge capacity Q3 being greater than a second capacity threshold, wherein the full discharge capacity Q4 is the full discharge capacity of the battery when the battery is charged to a fully charged state and discharged to a fully discharged state based on the charging current parameter value before the update.

[0024] In some embodiments, limiting conditions are added to trigger a correction process for the charging current parameter value after the battery has been used for a certain period of time or years, including: obtaining the capacity of the battery in response to the battery satisfying at least one of the following conditions: the number of battery cycles is greater than or equal to a first number threshold; the battery usage time is greater than or equal to a first time threshold; wherein the first number threshold includes N*the second number threshold, the first time threshold includes M*the second time threshold, and M and N are positive integers greater than or equal to 1.

[0025] After the battery has been used for a certain period of time or years, the battery capacity is obtained to trigger the process of correcting the charging current parameter value, so as to avoid frequently triggering the correction process of the charging current parameter value and occupying the resources of the BMS.

[0026] In some embodiments, the first step length is at least partially in a first positive correlation functional relationship with N; or, the first step length is at least partially in a second positive correlation functional relationship with M. As the battery ages, the aging rate increases, and the first step length increases with time, which can speed up the search for a suitable charging current parameter value and improve the speed of correcting the charging current parameter value.

[0027] In some embodiments, in response to the charging current parameter value being greater than or equal to a first current parameter threshold, the charging current parameter value is modified.

[0028] In a second aspect, an embodiment of the present application further provides a battery management system, including a processor and a memory, wherein the memory is used to store instructions, and the processor is used to execute instructions to implement the battery management method according to the first aspect.

[0029] In a third aspect, an embodiment of the present application further provides a battery device, including a battery pack and a battery management system as in the second aspect.

[0030] In a fourth aspect, an embodiment of the present application further provides an electrical device, including a battery pack and a battery management system as in the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] One or more embodiments are exemplarily described by the figures in the corresponding drawings, and these exemplary descriptions are not intended to limit the embodiments. Elements with the same reference numerals in the drawings represent similar elements.

[0032] Figure 1a is a schematic diagram of the structure of a battery pack according to an embodiment of the present application;

[0033] Figure 1b It is a schematic diagram of the structure of the electric device in the embodiment of the present application;

[0034] Figure 1c It is a schematic diagram of the structure of the electric device in the embodiment of the present application;

[0035] Figure 2 Schematic diagram of the hardware structure of the BMS of the embodiment of the present application;

[0036] Figure 3 It is a flowchart of a battery management method according to an embodiment of the present application;

[0037] Figure 4 It is a flowchart of the step of correcting the charging current parameter value in the battery management method of an embodiment of the present application;

[0038] Figure 5 It is a flow chart of the step of correcting the charging current parameter value in the battery management method according to an embodiment of the present application. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and in detail in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0040] In the embodiments of the present application, words such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying an order.

[0041] In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as there is no structural conflict between them.

[0042] Figure 1a A structure of an electric device 100 is shown. Figure 1a As shown, the electric device 100 includes a battery pack 10, and the battery pack 10 is used to supply power to the electric device 100 and store power to ensure the operation of the electric device 100. The electric device 100 is a device that needs to be powered by the battery pack 10, such as an electric car, an electric two-wheeled vehicle, an electric tool, a drone, an energy storage system, etc. The energy storage system includes an uninterruptible power supply (UPS), a household energy storage system, and an industrial and commercial energy storage system.

[0043] Figure 1b A structure of a battery device 200 is shown. The battery device 200 includes a battery pack 10 . The battery device 200 is a device for providing power.

[0044] The battery pack 10 includes a battery management system (BMS) 1 and a battery module 2 .

[0045] The battery module 2 is used to store and provide electric energy, and includes a plurality of battery cells, wherein the battery cells in the battery module are connected in series, in parallel or in a mixed connection mode, where the mixed connection mode means that the battery cells in the battery module are connected in both series and in parallel. The BMS1 is used to detect, manage and / or protect the battery module.

[0046] Figure 2 A hardware structure of BMS1 is schematically shown. Figure 2 As shown, the BMS 1 includes a processor 11 and a memory 12 .

[0047] The memory 12 is a non-volatile computer-readable storage medium that can be used to store non-volatile software programs and non-volatile computer-executable program instructions. The memory 12 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required for at least one function; and the data storage area may store data created according to the use of the BMS 1.

[0048] In addition, the memory 12 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 12 may optionally include a memory remotely arranged relative to the processor 11, and these remote memories may be connected to the BMS1 via a network.

[0049] Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network and combinations thereof.

[0050] The processor 11 uses various interfaces and lines to connect various parts of the entire BMS1, and executes various functions of the BMS1 and processes data by running or executing software programs stored in the memory 12 and calling data stored in the memory 12, such as implementing the method described in any embodiment of the present application.

[0051] The processor 11 may include a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) device, etc. The processor 1001 may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration.

[0052] Those skilled in the art can understand that Figure 2 In the example of a processor 11 and a memory 12, when the BMS 1 includes a multi-level management unit, or when multiple processors need to work together, the BMS 1 may also include multiple processors, and the method described in any embodiment of the present application may be implemented by the multiple processors working together. Similarly, the memory may be one or more, and the processor 11 and the memory 12 may be connected via a bus or other means. Figure 2 In the illustrated embodiment, the processor 11 and the memory 12 are connected via a bus.

[0053] Figure 1c A schematic diagram showing the connection between the battery pack 10 and the charging device 20 is shown, and the charging device 20 is, for example, a solar power generation system, a wind power generation system, or a municipal power supply system. The charging device 20 provides a charging current to charge the battery pack 10. In some embodiments, the charging device 20 is embodied as a charging pile, a charging cabinet, or a charging station.

[0054] In some embodiments, the embodiments of the present application are applied to a battery pack 10 and a charging device 20 with intelligent charging functions. When the battery pack 10 is connected to the charging device 20 for charging, the BMS1 communicates with the charging device 20, and the charging device 20 inquires about the maximum charging current allowed by the BMS1. The BMS1 determines the maximum value of the charging current according to the status of the battery pack 10 (such as battery health status, temperature, SOC, etc.), and feeds it back to the charging device 20. The charging device 20 charges the battery pack 10 according to the maximum charging current provided by the BMS1 to ensure that the charging process is carried out within a safe range.

[0055] In some of the embodiments, the BMS 1 feeds back the charging current parameter value to the charging device 20 according to the charging current parameter value stored in the BMS 1 , and the charging device 20 charges the battery pack 10 according to the charging current parameter value.

[0056] In some embodiments, the charging current parameter value includes a maximum allowable charging current or a maximum allowable charging rate. In other embodiments, the charging current parameter value includes a charging SOP value, and the charging SOP value includes at least one of a maximum allowable charging current, a maximum allowable charging power, and a maximum allowable charging voltage. In some of the following embodiments, the charging current parameter value is taken as an example of the maximum allowable charging current value.

[0057] In some embodiments, the charging current parameter value includes charging current parameter values ​​corresponding to multiple intervals, wherein the intervals include intervals corresponding to the battery temperature range and / or the battery SOC range, or the intervals include intervals corresponding to the battery temperature range and / or the battery voltage range.

[0058] In some embodiments, the charging current parameter value corresponding to each interval includes a single value. In other embodiments, each interval includes multiple sub-intervals, and the charging current parameter value corresponding to each interval includes charging current parameter values ​​corresponding to each sub-interval, and the charging current parameter value corresponding to each sub-interval changes in a step-by-step manner. Alternatively, within the interval, the charging current parameter value and the battery temperature and / or the battery SOC are at least partially in a first negatively correlated functional relationship. Alternatively, within the interval, the charging current parameter value and the battery temperature and / or the battery voltage are at least partially in a second negatively correlated functional relationship.

[0059] The first negative correlation function relationship includes one or more of a monotonically decreasing relationship, a linearly decreasing relationship, and a stepwise decreasing relationship. The second negative correlation function relationship includes one or more of a monotonically decreasing relationship, a linearly decreasing relationship, and a stepwise decreasing relationship.

[0060] Exemplarily, the BMS 1 obtains the current temperature and current voltage of the battery, confirms the interval in which the battery is located based on the current temperature and current voltage, obtains the charging current parameter value corresponding to the interval, and feeds the charging current parameter value back to the charging device 20 .

[0061] For another example, the BMS1 obtains the current temperature and current SOC of the battery, confirms the interval in which it is located based on the current temperature and current SOC, obtains the charging current parameter value corresponding to the interval, and feeds the charging current parameter value back to the charging device 20 .

[0062] In some related technologies, the charging current parameter value is solidified as a fixed parameter and is set based on the battery's factory status. However, in actual use, as the battery gradually ages, its performance declines, and the fixed charging current parameter value may cause a series of problems. For example, when the battery is aged, it is still charged according to the initially set charging SOP, which may cause the charging to be terminated early, the battery is not fully charged, and then show insufficient capacity during the discharge process. This situation not only reduces the actual use capacity of the battery and reduces the battery's energy efficiency, but may also accelerate the battery aging process and shorten the battery's service life.

[0063] In some embodiments of the present application, the charging current parameter value is a non-fixed value, and the charging current parameter value is dynamically modified during the use of the battery. When the battery capacity is less than or equal to the set first capacity threshold, the charging current parameter value is reduced to the first charging current parameter value. The first charging current parameter value is a parameter value that increases the battery capacity to exceed the second capacity threshold. When the battery is charged to a fully charged state according to the first charging current parameter value, the battery capacity is greater than the second capacity threshold.

[0064] In this implementation, when the battery ages, the charging current is reduced to charge the battery pack, providing more charging time for the cells with more severe aging, so that they are close to full charge, thereby increasing the overall capacity of the battery pack. Reducing the charging speed also helps to balance the voltage between cells, thereby improving the performance and consistency of the entire battery. Moreover, using a smaller and more appropriate charging current after the battery ages can reduce stress accumulation and slow down the aging process.

[0065] Please refer to Figure 3 , an embodiment of the present application provides a battery management method, including:

[0066] 101: Get the battery capacity.

[0067] The battery capacity includes the battery full charge capacity or the battery full discharge capacity. The battery full charge capacity refers to the total capacity absorbed by the battery when the battery is charged from a fully discharged state to a fully charged state. In other embodiments, the battery full charge capacity refers to the total capacity absorbed by the battery when the battery is charged from a discharge cut-off voltage to a charge cut-off voltage.

[0068] In some embodiments, the battery is charged from a fully discharged state to a fully charged state, including charging the battery from a fully discharged state to a fully charged state once, that is, the battery is fully charged after one charge. Alternatively, the battery is cumulatively charged from a fully discharged state to a fully charged state, that is, the battery is fully charged after multiple charges. In some embodiments, during the cumulative charging of the battery, there is no discharge for the load.

[0069] In one implementation, the full charge capacity of the battery is obtained by performing a time-integrated calculation on the charging current, that is, the integral of the product of the charging current and the charging time during the battery charging process is calculated to obtain the full charge capacity of the battery.

[0070] The full discharge capacity of a battery refers to the total capacity released by the battery when the battery is discharged from a fully charged state to a fully discharged state. In some embodiments, the full discharge capacity of a battery refers to the total capacity released by the battery when the battery is discharged from a charge cut-off voltage to a discharge cut-off voltage.

[0071] In some embodiments, the battery is discharged from a fully charged state to a fully discharged state, including a single discharge of the battery from a fully charged state to a fully discharged state, that is, a full discharge is completed after a single discharge. Alternatively, the battery is cumulatively discharged from a fully charged state to a fully discharged state, that is, the battery is fully discharged after multiple discharges. In some embodiments, there is no charging behavior during the cumulative discharge of the battery.

[0072] In one implementation, the full-discharge capacity of the battery is obtained by performing time-integrated calculation on the discharge current, that is, the integral of the product of the discharge current and the discharge time during the discharge process of the battery is calculated to obtain the full-discharge capacity of the battery.

[0073] 102: When the battery capacity is less than or equal to a first capacity threshold, modify the charging current parameter value to reduce the charging current parameter value to a first charging current parameter value.

[0074] The full discharge capacity of the battery reflects the available capacity that the battery can actually provide in the current state, and is one of the important indicators for evaluating battery performance and health. The full charge capacity of the battery is one of the important indicators of the actual capacity of the battery, which is used to measure the charging ability and health status of the battery. The reduction in battery capacity reflects the aging of the battery. When the battery capacity is less than or equal to the first capacity threshold, it indicates that the battery has aged, and the charging current parameter value is reduced to the first charging current parameter value.

[0075] The battery is charged according to the first charging current parameter value, so that the battery capacity increases to exceed the second capacity threshold, and the second capacity threshold is greater than the first capacity threshold. In the embodiment of the present application, when the battery ages, the battery capacity is increased by reducing the charging current parameter value to improve the battery performance.

[0076] In some embodiments, the first capacity threshold is k1*Qe (rated capacity), and the second capacity threshold is k2*Qe. The values ​​of k1 and k2 are determined based on the battery performance, type, service life, number of cycles, etc. Exemplarily, the first capacity threshold is 80% to 90% of the rated capacity, and the second capacity threshold is 90% to 99% of the rated capacity.

[0077] In some embodiments of the present application, a minimum value of the charging current parameter is set, such as a first current parameter threshold. When correcting the charging current parameter value, if the charging current parameter value is greater than or equal to the first current parameter threshold, the charging current parameter value is reduced. If the charging current parameter value is less than the first current parameter threshold, the charging current parameter value is not corrected, and the current charging current parameter value remains unchanged. For example, in the case where the charging current parameter value includes multiple charging current parameter values, only the charging current parameter values ​​greater than or equal to the first current parameter threshold are corrected.

[0078] In some embodiments, when the battery capacity is less than or equal to the first capacity threshold, the charging current parameter value is gradually reduced with a first step length until it is reduced to a value greater than the second capacity threshold when full charging is completed based on the updated charging current parameter value. By correcting the original charging current parameter value by gradually decreasing the step length, a better charging current parameter value suitable for the current battery state can be found, thereby optimizing the capacity performance after full charging, delaying battery aging, and increasing the battery life. In some embodiments, the charging current parameter value is corrected based on the change in the full charge capacity of the battery. For details, please refer to Figure 4 , correct the charging current parameter values, including:

[0079] 1021a: Subtract the first step length from the charging current parameter value.

[0080] The first step length can be set according to the battery type and battery performance, etc. For example, when the charging current parameter value is the charging current value, the first step length is 1A.

[0081] 1022a: When the battery is charged to a fully charged state based on the updated charging current parameter value, the full charge capacity Q1 of the battery is calculated.

[0082] The battery is charged to a fully charged state based on the updated charging current parameter value, including: the battery is charged from a fully discharged state to a fully charged state in a single charge, that is, the battery is fully charged after one charge. Alternatively, the battery is cumulatively charged from a fully discharged state to a fully charged state, that is, the battery is fully charged after multiple charges. In some embodiments, during the cumulative charging of the battery, there is no discharge for the load.

[0083] 1023a: Compare the full charge capacity Q1 and the full charge capacity Q2, where the full charge capacity Q2 is the full charge capacity of the battery when the battery is charged to a fully charged state based on the charging current parameter value before the update, and compare the full charge capacity Q1 and the second capacity threshold QN. When the full charge capacity Q1 is greater than the full charge capacity Q2, and the full charge capacity Q1 is less than or equal to the second capacity threshold QN, jump to step 1021a and execute 1021a and 1022a, until the full charge capacity Q1 is greater than the full charge capacity Q2, and the full charge capacity Q1 is greater than the second capacity threshold QN, execute step 1024a.

[0084] 1024a: Complete the correction of the charging current parameter value and store the corrected charging current parameter value.

[0085] After the charging current parameter value is lowered for the first time, when the battery completes full charge based on the reduced charging current parameter value, the full charge capacity will increase, that is, the full charge capacity Q1 after the parameter update is greater than the full charge capacity Q2 before the parameter update. If the full charge capacity Q1 is less than the second capacity threshold QN, the charging current parameter value continues to be lowered, and the charging current parameter value is subtracted by (2×the first step length) to charge the battery pack. The above operation is repeated until the full charge capacity Q1 is greater than the second capacity threshold QN, and the correction of the charging current parameter value is completed. In some embodiments, the corrected parameter value is stored in a non-volatile storage medium. It can be understood that when charging the battery pack for the Nth time, the charging current parameter value is the first charging current parameter value-(N×the first step length).

[0086] In some embodiments, in step 1023a, if the full charge capacity Q1 after the parameter update is less than or equal to the full charge capacity Q2 before the parameter update, the charging current parameter value is not further reduced and the correction is terminated.

[0087] In other embodiments, the charging current parameter value is modified based on the change in the full discharge capacity of the battery. Figure 5 , correct the charging current parameter values, including:

[0088] 1021b: Subtract the first step length from the charging current parameter value.

[0089] The first step length can be set according to the battery type and battery performance, etc. For example, when the charging current parameter value is the charging current value, the first step length is 1A.

[0090] 1022b: After the battery is charged to a fully charged state based on the updated charging current parameter value, it is discharged to a fully discharged state, and the full discharge capacity Q3 of the battery is calculated.

[0091] The battery is discharged to a fully discharged state, including: the battery is discharged from a fully charged state to a fully discharged state once, that is, the battery is fully discharged after one discharge. Alternatively, the battery is discharged from a fully charged state to a fully discharged state cumulatively, that is, the battery is fully discharged after multiple discharges. In some embodiments, there is no charging behavior during the cumulative discharge of the battery.

[0092] 1023b: Compare the full capacity Q3 and the full capacity Q4, where the full capacity Q4 is the full capacity of the battery after the battery is charged to a fully charged state based on the charging current parameter value before the update and then discharged to a fully discharged state, and compare the full capacity Q3 and the second capacity threshold QN. When the full capacity Q3 is greater than the full capacity Q4 and the full capacity Q3 is less than or equal to the second capacity threshold QN, jump to step 1021b and execute 1021b and 1022b until the full capacity Q3 is greater than the full capacity Q4 and the full capacity Q3 is greater than the second capacity threshold QN, and then execute step 1024b.

[0093] 1024b: Complete the correction of the charging current parameter value, and store and output the corrected charging current parameter value.

[0094] After the charging current parameter value is reduced for the first time, when the battery is fully charged and discharged to a fully discharged state based on the reduced charging current parameter value, the full discharge capacity will increase, that is, the full discharge capacity Q3 after the parameter update is greater than the full discharge capacity Q4 before the parameter update. If the full discharge capacity Q3 is less than the second capacity threshold QN, the charging current parameter value is continued to be reduced, and the charging current parameter value is subtracted by (2×the first step length) to charge the battery pack, and the above operation is performed repeatedly until the full discharge capacity Q3 is greater than the second capacity threshold QN, and the correction of the charging current parameter value is completed. In some embodiments, the corrected parameter value is stored in a non-volatile storage medium.

[0095] In some embodiments, in step 1023b, if the full discharge capacity Q3 after the parameter update is less than or equal to the full discharge capacity Q4 before the parameter update, the charging current parameter value is not further reduced and the current correction is terminated.

[0096] If the correction process of the charging current parameter value is triggered frequently, the resources of BMS1 will be occupied, affecting other functions of BMS1 (such as charging and discharging management, safety management, etc.). Therefore, in some embodiments, a limiting condition is added to trigger the correction process of the charging current parameter value after the battery has been used for a certain period of time or years.

[0097] In some embodiments, when the battery usage time is greater than or equal to the first time threshold, the battery capacity is obtained, triggering the process of modifying the charging current parameter value. In other embodiments, when the number of battery cycles is greater than or equal to the first number threshold, the battery capacity is obtained, triggering the process of modifying the charging current parameter value.

[0098] In some embodiments, the charging current parameter value is corrected at intervals, and the first time threshold includes N*the second time threshold, or the first time threshold includes M*the second time threshold, where M and N are positive integers greater than or equal to 1. The second time threshold is the usage time interval, for example, when the second time threshold is 1 year, the first time threshold is 1 year, 2 years, ..., N years, and the charging current parameter value is corrected every year. The second number threshold is the cycle number interval, for example, when the second number threshold is 200 cycles, the first number threshold is 200 times, 400 times, ..., M*200 times, and the charging current parameter value is corrected every 200 cycles of the battery.

[0099] Exemplarily, the charging current parameter value is corrected once every year that the battery is operated, or once every 200 cycles of the battery.

[0100] The battery will age more rapidly with the use time. In some embodiments, in order to improve the speed of correcting the charging current parameter value, the first step length increases with the increase of time to speed up the search for a suitable charging current parameter value. In some embodiments, the first step length is at least partially in a first positive correlation functional relationship with N, or the first step length is at least partially in a second positive correlation functional relationship with M.

[0101] Among them, the first positive correlation function relationship includes one or more of a monotonically increasing relationship, a linearly increasing relationship, and a step-increasing relationship, and the second positive correlation function relationship includes one or more of a monotonically increasing relationship, a linearly increasing relationship, and a step-increasing relationship.

[0102] As the battery ages, the expectation of the battery capacity should be lowered. In order to find a better charging current parameter value suitable for the current battery state, the first capacity threshold and the second capacity threshold decrease as the battery usage time or cycle number increases. In some embodiments, the first capacity threshold is negatively correlated with M or N, and the second capacity threshold is negatively correlated with M or N. For the negative correlation function relationship, please refer to the above explanation of the first negative correlation function relationship and the second negative correlation function relationship, which will not be repeated here.

[0103] The following takes one of the embodiments as an example to illustrate the correction process of the charging current parameter value.

[0104] S1: When the battery usage meets the first condition, obtain the battery capacity.

[0105] Among them, the first condition includes that the battery is used for 1 year, 2 years, ..., N-1 years or N years, or the battery cycle times reach 100 times, 200 times, ..., M-1 hundred times or M hundred times.

[0106] S2: When the battery full charge capacity is less than or equal to 90% Qe (rated capacity), record the full charge capacity Q0 at this time, reduce the maximum charging current value by one step △I (△I=1A), and calculate the full charge capacity Q1 when the battery is fully discharged and fully charged according to the updated maximum charging current value.

[0107] S3: If Q1>Q0 ， If Q1 is less than or equal to 98% Qe, the maximum charging current value is further reduced by one step, that is, reduced by 2 on the basis of the original maximum charging current value. × △I. When the battery is fully discharged and fully charged according to the updated maximum charging current value, the full charge capacity Q2 is calculated.

[0108] S4: If Q2>Q1 ， If Q2 is less than or equal to 98% Qe, the maximum charging current value is further reduced by one step, that is, 3 steps are reduced based on the original maximum charging current value. × △I. When the battery is fully discharged and fully charged according to the updated maximum charging current value, the full charge capacity Q3 is calculated.

[0109] …

[0110] Sn+1: if Qn>Qn-1 ， And Qn is greater than 98% Qe, the maximum charging current value is corrected, and the corrected maximum charging current value is: the original maximum charging current value minus n × △I. The corrected maximum charging current value is stored in a non-volatile readable storage medium, and when charging is subsequently performed by a charging device, the corrected maximum charging current value is fed back to the charging device, and the charging device charges the battery pack 20 according to the corrected maximum charging current value.

[0111] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

[0112] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them. Under the idea of ​​the present application, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. It should be understood by ordinary technicians in this field that they can still modify the technical solutions recorded in the above embodiments, or replace some of the technical features by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery management method, characterized in that: include: Obtaining battery capacity, where the battery capacity includes battery full charge capacity or battery full discharge capacity; In response to the battery capacity being less than or equal to a first capacity threshold, modifying the charging current parameter value to reduce the charging current parameter value to a first charging current parameter value; In response to the battery being charged to a fully charged state according to the first charging current parameter value, the battery capacity is greater than a second capacity threshold, and the second capacity threshold is greater than the first capacity threshold.

2. The method according to claim 1, characterized in that Get the battery full charge capacity, including: In response to a single charge of the battery from a fully discharged state to a fully charged state, calculating the capacity of the battery charge; or, responsive to the battery being cumulatively charged from a fully discharged state to a fully charged state, calculating a capacity of the battery charge; Get the battery full-discharge capacity, including: In response to a single discharge of the battery from a fully charged state to a fully discharged state, calculating the discharged capacity of the battery; or, In response to the battery cumulatively being discharged from a fully charged state to a fully discharged state, a discharged capacity of the battery is calculated.

3. The method according to claim 2, characterized in that The modified charging current parameter value includes: S1: Subtract the first step length from the charging current parameter value to update the charging current parameter value; S2: in response to the battery being charged to a fully charged state based on the updated charging current parameter value, calculating the full charge capacity Q1 of the battery; The battery is charged to a fully charged state based on the updated charging current parameter value, including: the battery is charged from a fully discharged state to a fully charged state once, or the battery is cumulatively charged from a fully discharged state to a fully charged state; S3: S3.1 In response to the full charge capacity Q1 being greater than the full charge capacity Q2 when the battery is charged to a fully charged state, and the full charge capacity Q1 being less than or equal to a second capacity threshold, jump to S1 and execute steps S1 and S2; S3.2 In response to the full charge capacity Q1 being greater than the full charge capacity Q2 when the battery is charged to a fully charged state, and the full charge capacity Q1 being greater than the second capacity threshold, completing the correction of the charging current parameter value; The full charge capacity Q2 is defined as the full charge capacity of the battery when the battery is charged to a fully charged state based on the charging current parameter value before the update; The charging current parameter value includes a maximum allowable charging current or a maximum allowable charging rate.

4. The method according to claim 2, characterized in that: The modified charging current parameter value includes: A1: Subtract the first step length from the charging current parameter value to update the charging current parameter value; A2: in response to the battery being charged to a fully charged state and discharged to a fully discharged state based on the updated charging current parameter value, calculating the full discharge capacity Q3 of the battery; The battery discharges from a fully charged state to a fully discharged state, including: the battery discharges from a fully charged state to a fully discharged state once, or the battery discharges from a fully charged state to a fully discharged state cumulatively; A3: A3.1 In response to the full discharge capacity Q3 being greater than the full discharge capacity Q4 when the battery is discharged from a fully charged state to a fully discharged state, and the full discharge capacity Q3 being less than or equal to a second capacity threshold, jump to A1 and execute steps A1 and A2; A3.2 In response to the full discharge capacity Q3 being greater than the full discharge capacity Q4 when the battery is discharged from a fully charged state to a fully discharged state, and the full discharge capacity Q3 being greater than the second capacity threshold, completing the correction of the charging current parameter value; The full discharge capacity Q4 is defined as the full discharge capacity of the battery when the battery is charged to a fully charged state and discharged to a fully discharged state based on the charging current parameter value before the update; The charging current parameter value includes a maximum allowable charging current or a maximum allowable charging rate.

5. The method according to claim 3 or 4, characterized in that: In response to the battery satisfying at least one of the following conditions, obtaining the capacity of the battery: The number of cycles of the battery is greater than or equal to a first number threshold; The battery usage time is greater than or equal to a first time threshold; The first number threshold includes N*the second number threshold, the first time threshold includes M*the second time threshold, and M and N are positive integers greater than or equal to 1.

6. The method according to claim 5, characterized in that The first step length is at least partially in a first positive correlation functional relationship with N; or, the first step length is at least partially in a second positive correlation functional relationship with M.

7. The method according to any one of claims 1 to 6, characterized in that: The modified charging current parameter value includes: In response to the charging current parameter value being greater than or equal to a first current parameter threshold, the charging current parameter value is modified.

8. A battery management system, characterized in that: It comprises a processor and a memory, wherein the memory is used to store instructions, and the processor is used to execute the instructions to implement the battery management method according to any one of claims 1 to 7.

9. A battery device, characterized in that: It comprises a battery pack and a battery management system as claimed in claim 8.

10. An electrical device, characterized in that: It comprises a battery pack and a battery management system as claimed in claim 8.

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