A battery capacity estimation method and device, and a computer readable storage medium
By segmenting and analyzing the discharge voltage-time curve of lithium batteries, and using the boundary voltage to cut off charging, discharging is only performed on irregular segments. This solves the problem of long battery capacity testing time in existing technologies and achieves efficient capacity prediction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- EVE POWER CO LTD
- Filing Date
- 2023-12-28
- Publication Date
- 2026-07-21
AI Technical Summary
Existing technologies for lithium battery capacity testing are time-consuming, involve long charging and discharging times, require significant equipment investment, occupy a large area, and make it difficult to efficiently classify capacity levels.
By identifying the regular and irregular segments of the discharge voltage-time curve during a battery charge-discharge cycle, a curve function is fitted, and charging is cut off using the boundary voltage. Discharge is only performed on the irregular segments, and the capacity is estimated by combining the regular segments, thereby reducing the charge-discharge time.
It shortens the battery capacity prediction cycle, improves the battery capacity prediction efficiency, and reduces charging and discharging time and equipment investment.
Smart Images
Figure CN117805625B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and in particular to a method and apparatus for estimating battery capacity, and a computer-readable storage medium. Background Technology
[0002] During the battery production process, after the batteries are sealed, capacity tests are conducted and the batteries are categorized according to their capacity to ensure that the capacity of the matched batteries is consistent.
[0003] Taking lithium batteries as an example, related technologies typically involve a full charge and discharge cycle to determine the battery capacity, which takes more than 6 hours. This process results in long charging and discharging times, large investments in capacity assessment equipment, and requires a lot of space. Summary of the Invention
[0004] To address the aforementioned issues, this application provides a method and apparatus for estimating battery capacity, as well as a computer-readable storage medium, which can improve the efficiency of battery capacity estimation.
[0005] One technical solution adopted in this application is: providing a method for estimating battery capacity, the method comprising: determining regular and irregular segments of the discharge voltage-time curve corresponding to a battery charge-discharge cycle; determining the boundary voltage corresponding to the boundary point of the regular and irregular segments, and determining the first capacity corresponding to the regular segment; charging the battery under test with the boundary voltage as the charging cutoff voltage; discharging the battery under test charged to the charging cutoff voltage and determining the corresponding second capacity; and determining the estimated capacity of the battery under test based on the first capacity and the second capacity.
[0006] In one embodiment, determining the regular and irregular segments of the discharge voltage-time curve corresponding to a battery charge-discharge cycle includes: performing full charge and discharge on multiple batteries; obtaining the discharge voltage-time curves corresponding to the full charge and discharge process of the multiple batteries; determining the overlapping portions of the multiple discharge voltage-time curves as regular segments, and determining the differing portions of the multiple discharge voltage-time curves as irregular segments.
[0007] In one embodiment, fully charging and discharging multiple batteries includes fully charging and discharging multiple batteries of different capacities.
[0008] In one embodiment, determining the first capacity corresponding to a regular segment includes: fitting a curve function to a regular segment of multiple discharge voltage-time curves; determining the first discharge time corresponding to the regular segment based on the curve function and the boundary voltage; and determining the first capacity corresponding to the regular segment based on the discharge current and the first discharge time corresponding to the regular segment.
[0009] In one embodiment, fitting a curve function based on regular segments of multiple discharge voltage-time curves includes: fitting multiple initial functions based on the regular segments of the multiple discharge voltage-time curves respectively; and averaging the coefficients of the multiple initial functions to obtain the curve function.
[0010] In one embodiment, fitting multiple initial functions to regular segments of multiple discharge voltage-time curves includes: fitting multiple initial functions to regular segments of multiple discharge voltage-time curves using the following preset function: V(t) = t 2 +bt+c; where V(t) represents a preset function with time t as the independent variable and discharge voltage as the function value, and a, b, and c are coefficients respectively.
[0011] In one embodiment, discharging a battery under test charged to a charging cutoff voltage and determining the corresponding second capacity includes: discharging the battery under test charged to a charging cutoff voltage and determining the corresponding second discharge time; and determining the corresponding second capacity based on the corresponding discharge current and the second discharge time.
[0012] In one embodiment, the method further includes: if the difference between the estimated capacity and the actual capacity of the battery under test is greater than a set threshold, adjusting the boundary voltage, and performing the step of determining the boundary voltage corresponding to the boundary point of the regular segment and the irregular segment again.
[0013] One technical solution adopted in this application is to provide a battery capacity estimation device, which includes a processor and a memory. The memory is used to store program data, and the processor is used to execute the program data to implement the battery capacity estimation method as described above.
[0014] One technical solution adopted in this application is to provide a computer-readable storage medium that stores program data, which, when executed by a processor, is used to implement the battery capacity estimation method described above.
[0015] The battery capacity estimation method provided in this application includes: determining the regular and irregular segments of the discharge voltage-time curve corresponding to the battery charge-discharge cycle; determining the boundary voltage corresponding to the boundary point between the regular and irregular segments, and determining the first capacity corresponding to the regular segment; charging the battery under test with the boundary voltage as the charging cutoff voltage; discharging the battery under test charged to the charging cutoff voltage and determining the corresponding second capacity; and determining the estimated capacity of the battery under test based on the first and second capacities. By dividing the discharge voltage-time curve into two segments and pre-calculating the first capacity of the regular segment, when actually estimating the capacity of the battery under test, it is not necessary to fully charge the battery under test; only the second capacity of the irregular segment needs to be calculated. Then, the estimated capacity is calculated based on the first and second capacities. This greatly saves charging and discharging time, thereby shortening the battery capacity estimation cycle and improving the efficiency of battery capacity estimation. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a flowchart illustrating an embodiment of the battery capacity estimation method provided in this application;
[0018] Figure 2 yes Figure 1 A flowchart illustrating an embodiment of step S11;
[0019] Figure 3 This is a schematic diagram of the discharge voltage-time curves corresponding to multiple batteries in one embodiment;
[0020] Figure 4 yes Figure 1 A flowchart illustrating an embodiment of step S12;
[0021] Figure 5 This is a schematic diagram comparing the estimated capacity with the measured capacity in one embodiment;
[0022] Figure 6 This is a schematic diagram of an embodiment of the battery capacity estimation device provided in this application;
[0023] Figure 7 This is a schematic diagram of an embodiment of the computer-readable storage medium provided in this application. Detailed Implementation
[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0025] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.
[0026] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.
[0027] The use of "applies to" or "configured to" in this application implies open and inclusive language, which does not exclude the applicability to or configuration to devices performing additional tasks or steps. Additionally, the use of "based on" implies openness and inclusivity, because processes, steps, calculations, or other actions "based on" one or more of the stated conditions or values may in practice be based on additional conditions or values beyond those stated.
[0028] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.
[0029] See Figure 1 , Figure 1 This is a flowchart illustrating an embodiment of the battery capacity estimation method provided in this application. The method includes:
[0030] Step S11: Determine the regular and irregular segments of the discharge voltage-time curve corresponding to the battery charge-discharge cycle.
[0031] Optionally, the battery is typically a lithium-ion battery.
[0032] The discharge voltage-time curve is formed by real-time monitoring of the battery's discharge voltage during the charge-discharge cycle and establishing the relationship between discharge voltage and time. Optionally, this charge-discharge cycle is generally a full charge and discharge cycle, that is, charging the battery to 100% capacity and then discharging it to 0%.
[0033] Among them, the regular segment refers to the part where the discharge voltage and time curves of different batteries overlap (or a highly similar segment), while the irregular segment refers to the part where the discharge voltage and time curves of different batteries differ.
[0034] Alternatively, in one embodiment, as Figure 2 As shown, Figure 2 yes Figure 1 A flowchart illustrating an embodiment of step S11, which may include:
[0035] Step S111: Fully charge and discharge multiple batteries.
[0036] Optionally, step S111 may include: fully charging and discharging multiple batteries with different capacities. Here, the capacity can be the rated capacity. Of course, in other embodiments, the capacity of the multiple batteries can be selected according to the actual situation. If the estimated battery capacity needs to be from the same batch or with the same capacity parameters, then multiple batteries with the same capacity can also be fully charged and discharged.
[0037] Step S112: Obtain the discharge voltage-time curves corresponding to the full charge and discharge processes of multiple batteries.
[0038] Optionally, in one embodiment, the discharge voltage-time curve is established using an XOY coordinate system, where time is the horizontal axis and discharge voltage is the vertical axis.
[0039] Step S113: Determine the overlapping portions of multiple discharge voltage-time curves as regular segments, and determine the differing portions of multiple discharge voltage-time curves as irregular segments.
[0040] Optionally, in one embodiment, the discharge voltage-time curves corresponding to multiple batteries can be plotted in the same XOY coordinate system to determine the overlapping and differing portions of the multiple discharge voltage-time curves.
[0041] like Figure 3 As shown, Figure 3 This is a schematic diagram of the discharge voltage-time curves corresponding to multiple batteries in one embodiment. This embodiment takes three discharge voltage-time curves as an example. In other embodiments, a certain number of batteries can be selected for the experiment according to the actual situation. For example, 10 batteries can be selected.
[0042] from Figure 3 As can be seen from the data, during the entire discharge process, the discharge voltage-time curves of the different discharge voltages from 4300mV to 3700mV basically overlap, while the 3700mV-2700mV range shows a significant difference. Therefore, the 4300mV-3700mV range can be identified as the regular segment, and the 3700mV-2700mV range can be identified as the irregular segment.
[0043] In one embodiment, multiple discharge voltage values corresponding to the same moment can be determined based on multiple discharge voltage-time curves, and the differences between the multiple discharge voltage values can be determined. If the difference between any two discharge voltage values is less than a set threshold, then the moment can be considered to correspond to a regular segment. If the difference between two discharge voltages is greater than the set threshold, then the moment can be considered to correspond to an irregular segment.
[0044] Step S12: Determine the boundary voltage corresponding to the boundary between regular and irregular segments, and determine the first capacity corresponding to the regular segment.
[0045] Alternatively, also in Figure 3 For example, the boundary voltage between the regular and irregular segments is 3700mV. Then, the first capacity is determined by the regular segment of the discharge voltage-time curve. This first capacity can be calculated based on the charging parameters collected from the regular segment. In one embodiment, the discharge process is a constant current discharge, so the corresponding first capacity can be calculated based on the discharge current and discharge time.
[0046] Optionally, such as Figure 4 As shown, Figure 4 yes Figure 1 A flowchart illustrating an embodiment of step S12, which may include:
[0047] Step S121: Fit a curve function based on the regular segments of multiple discharge voltage-time curves.
[0048] Understandably, based on a large amount of experimental data, it has been proven that the regular segment of the discharge voltage-time curve conforms to a quadratic curve, so the curve function of the quadratic curve can be used to fit the regular segment.
[0049] Optionally, in one embodiment, step S121 may include: fitting multiple initial functions according to regular segments of multiple discharge voltage-time curves; and averaging the coefficients of the multiple initial functions to obtain curve functions.
[0050] Specifically, first determine the curve function corresponding to the regular segment of each discharge voltage-time curve:
[0051] V(t)=t 2 +bt+c;
[0052] Where V(t) represents a preset function with time t as the independent variable and discharge voltage as the function value, and a, b, and c are coefficients respectively.
[0053] By substituting multiple sets of discharge voltage and time values for a regular segment of a curve into the above formula, a corresponding quadratic function is obtained through fitting. Taking three batteries as an example, the fitting yields several initial functions as follows:
[0054] V1=a1t 2 +b1t+c1;
[0055] V2=a2t 2 +b2t+c2;
[0056] V3=a3t 2 +b3t+c3;
[0057] Then, we determine that the mean of a1, a2, and a3 is a0, the mean of b1, b2, and b3 is b0, and the mean of c1, c2, and c3 is c0, resulting in the following curve function:
[0058] V=a0t 2 +b0t+c0.
[0059] Step S122: Determine the first discharge time corresponding to the regular segment based on the curve function and the boundary voltage.
[0060] Substituting the dividing point voltage V0 into the above formula V=a0t 2 In +b0t+c0, the corresponding first discharge time t1 can be calculated.
[0061] Step S123: Determine the first capacity corresponding to the rule segment based on the discharge current and the first discharge time corresponding to the rule segment.
[0062] Since the above-described full charge and discharge process uses constant current charging and constant current discharging, the first capacity C1 can be calculated using the following formula:
[0063] C1 = I1 * t1;
[0064] Where I1 is the discharge current.
[0065] In one embodiment, with Figure 2 For example, the critical voltage V0 is determined to be between 3600mV and 4000mV, for instance, it can be determined to be 3700mV, using the formula V = at. 2 The fitting yields the following coefficients: a = 0.0445, b = -10.322, c = 4118.6, therefore V = 0.0445t. 2 Given -10.322t + 4118.6, when V = 3.7, we find t = 1.13 (h). Therefore:
[0066] C1 = I1 * 1.13.
[0067] Optionally, in one embodiment, steps S11 and S12 described above can be performed using two batches of batteries, as detailed below:
[0068] The first batch of batteries were fully charged and discharged, and the discharge voltage-time curve of each battery was obtained. Based on the above multiple discharge voltage-time curves, the dividing point voltage V0 was initially selected.
[0069] The second batch of batteries was fully charged and discharged. Based on the aforementioned boundary voltage V0, a quadratic curve function was fitted to the regular segment of each boundary voltage V0 to obtain the aforementioned V = a0t. 2 +b0t+c0.
[0070] Finally, substituting the dividing point voltage V0 into V = a0t 2 +b0t+c0, calculate the corresponding first discharge time t1, and then calculate the corresponding first capacity C1.
[0071] Understandably, steps S11 and S12 above are performed during the experimental stage, meaning that the first capacity C1 can be determined in advance through testing. When estimating the capacity of each battery under test in the future, the first capacity C1 does not need to be measured again.
[0072] Step S13: Charge the battery under test using the boundary point voltage as the charging cutoff voltage.
[0073] The battery under test is charged to the aforementioned boundary voltage V0.
[0074] Understandably, in one application scenario, the battery under test is a brand new battery, meaning that this charge-discharge or capacity test is the first time for this battery.
[0075] Step S14: Discharge the battery under test that has been charged to the charging cutoff voltage and determine the corresponding second capacity.
[0076] Among them, step S14 corresponds to the process of full loading.
[0077] Optionally, in one embodiment, step S14 may include: discharging the battery under test charged to the charging cutoff voltage and determining the corresponding second discharge time t2; determining the corresponding second capacity C2 based on the corresponding discharge current I2 and the second discharge time t2, specifically:
[0078] C2 = I2 * t2.
[0079] Step S15: Determine the estimated capacity of the battery under test based on the first capacity and the second capacity.
[0080] Specifically, the estimated capacity is C0 = C1 + C2.
[0081] Understandably, according to the steps S13-S15 above, when estimating the capacity of the battery to be tested, it is not necessary to fully charge and discharge it. It is only necessary to charge it to the set dividing point voltage V0, and then fully discharge the battery to estimate its capacity.
[0082] Optionally, in one embodiment, if the difference between the estimated capacity and the actual capacity (measured capacity) of the battery under test is greater than a set threshold, the boundary voltage is adjusted, and the step of determining the boundary voltage corresponding to the boundary between the regular segment and the irregular segment is performed again. Specifically, the above steps S11-S12 can be repeated until the determined boundary voltage meets the subsequent prediction requirements.
[0083] Further reading Figure 5 , Figure 5 This is a schematic diagram comparing the estimated capacity and the measured capacity in one embodiment. Figure 5 It can be seen that the error between the estimated capacity and the measured capacity is within ±0.5%, which meets the requirements for capacity estimation.
[0084] The battery capacity estimation method provided in this embodiment includes: determining the regular and irregular segments of the discharge voltage-time curve corresponding to the battery charge-discharge cycle; determining the boundary voltage corresponding to the boundary point of the regular and irregular segments, and determining the first capacity corresponding to the regular segment; charging the battery under test with the boundary voltage as the charging cutoff voltage; discharging the battery under test charged to the charging cutoff voltage and determining the corresponding second capacity; and determining the estimated capacity of the battery under test based on the first and second capacities. By dividing the discharge voltage-time curve into two segments and pre-calculating the first capacity of the regular segment, when actually estimating the capacity of the battery under test, it is not necessary to fully charge the battery under test; only the second capacity of the irregular segment needs to be calculated. Then, the estimated capacity is calculated based on the first and second capacities. This greatly saves charging and discharging time, thereby shortening the battery capacity estimation cycle and improving the efficiency of battery capacity estimation.
[0085] See Figure 6 , Figure 6 This is a schematic diagram of an embodiment of the battery capacity estimation device provided in this application. The estimation device 600 includes a processor 601 and a memory 602. The memory 602 is used to store program data, and the processor 601 is used to execute the program data to implement the following battery capacity estimation method:
[0086] Determine the regular and irregular segments of the discharge voltage-time curve corresponding to the battery charge-discharge cycle; determine the boundary voltage corresponding to the boundary point between the regular and irregular segments, and determine the first capacity corresponding to the regular segment; charge the battery under test with the boundary voltage as the charging cutoff voltage; discharge the battery under test charged to the charging cutoff voltage and determine the corresponding second capacity; determine the estimated capacity of the battery under test based on the first capacity and the second capacity.
[0087] In one embodiment, the processor 601 is configured to perform: determining regular and irregular segments of the discharge voltage-time curve corresponding to a battery charge-discharge cycle, including: performing full charge and discharge on multiple batteries; acquiring discharge voltage-time curves corresponding to the full charge and discharge processes of multiple batteries; determining the overlapping portions of the multiple discharge voltage-time curves as regular segments, and determining the differing portions of the multiple discharge voltage-time curves as irregular segments.
[0088] In one embodiment, the processor 601 is configured to perform: fully charging and discharging multiple batteries of different capacities.
[0089] In one embodiment, the processor 601 is configured to perform: fitting a curve function to a regular segment of a plurality of discharge voltage-time curves; determining a first discharge time corresponding to the regular segment based on the curve function and the boundary voltage; and determining a first capacity corresponding to the regular segment based on the discharge current corresponding to the regular segment and the first discharge time.
[0090] In one embodiment, the processor 601 is configured to perform: fitting multiple initial functions according to regular segments of multiple discharge voltage-time curves; and averaging the coefficients of the multiple initial functions to obtain curve functions.
[0091] In one embodiment, the processor 601 is configured to perform the following: fitting multiple initial functions to regular segments of multiple discharge voltage-time curves using the following preset function: V(t) = t 2 +bt+c; where V(t) represents a preset function with time t as the independent variable and discharge voltage as the function value, and a, b, and c are coefficients respectively.
[0092] In one embodiment, the processor 601 is configured to: discharge the battery under test charged to the charging cutoff voltage and determine the corresponding second discharge time; and determine the corresponding second capacity based on the corresponding discharge current and the second discharge time.
[0093] In one embodiment, the processor 601 is configured to perform the following steps: if the difference between the estimated capacity and the actual capacity of the battery under test is greater than a set threshold, adjust the boundary voltage, and then perform the step of determining the boundary voltage corresponding to the boundary between the regular segment and the irregular segment again.
[0094] See Figure 7 , Figure 7 This is a schematic diagram of an embodiment of the computer-readable storage medium provided in this application. The computer-readable storage medium 700 stores program data 701, which, when executed by a processor, is used to implement a battery capacity estimation method as follows:
[0095] Determine the regular and irregular segments of the discharge voltage-time curve corresponding to the battery charge-discharge cycle; determine the boundary voltage corresponding to the boundary point between the regular and irregular segments, and determine the first capacity corresponding to the regular segment; charge the battery under test with the boundary voltage as the charging cutoff voltage; discharge the battery under test charged to the charging cutoff voltage and determine the corresponding second capacity; determine the estimated capacity of the battery under test based on the first capacity and the second capacity.
[0096] In one embodiment, when the program data 701 is executed by the processor, it is used to: determine the regular and irregular segments of the discharge voltage-time curve corresponding to the battery charge-discharge cycle, including: performing full charge and discharge on multiple batteries; obtaining the discharge voltage-time curves corresponding to the full charge and discharge process of multiple batteries; determining the overlapping parts of the multiple discharge voltage-time curves as regular segments, and determining the different parts of the multiple discharge voltage-time curves as irregular segments.
[0097] In one embodiment, when the program data 701 is executed by the processor, it is used to perform full charging and discharging of multiple batteries with different capacities.
[0098] In one embodiment, when the program data 701 is executed by the processor, it is used to: fit a curve function to a regular segment of a plurality of discharge voltage-time curves; determine the first discharge time corresponding to the regular segment based on the curve function and the boundary voltage; and determine the first capacity corresponding to the regular segment based on the discharge current corresponding to the regular segment and the first discharge time.
[0099] In one embodiment, when the program data 701 is executed by the processor, it is used to: fit multiple initial functions according to regular segments of multiple discharge voltage-time curves; and average the coefficients of the multiple initial functions to obtain curve functions.
[0100] In one embodiment, when the program data 701 is executed by the processor, it is used to: fit multiple initial functions to regular segments of multiple discharge voltage-time curves using the following preset function: V(t) = t 2 +bt+c; where V(t) represents a preset function with time t as the independent variable and discharge voltage as the function value, and a, b, and c are coefficients.
[0101] In one embodiment, when the program data 701 is executed by the processor, it is used to: discharge the battery under test that has been charged to the charging cutoff voltage and determine the corresponding second discharge time; and determine the corresponding second capacity based on the corresponding discharge current and the second discharge time.
[0102] In one embodiment, when the program data 701 is executed by the processor, it is used to: if the difference between the estimated capacity and the actual capacity of the battery under test is greater than a set threshold, adjust the boundary voltage, and execute the step of determining the boundary voltage corresponding to the boundary point of the regular segment and the irregular segment again.
[0103] The display screen provided in the embodiments of this application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A method for estimating battery capacity, characterized in that, The method for estimating battery capacity includes: Identify the regular and irregular segments of the discharge voltage-time curve corresponding to the battery charge-discharge cycle; Determine the boundary voltage corresponding to the boundary point between the regular segment and the irregular segment, and determine the first capacity corresponding to the regular segment; The battery under test is charged using the aforementioned dividing point voltage as the charging cutoff voltage; The battery under test, charged to the charging cutoff voltage, is discharged, and the corresponding second capacity is determined. The estimated capacity of the battery under test is determined based on the first capacity and the second capacity; The determination of the regular and irregular segments of the discharge voltage-time curve corresponding to the battery charge-discharge cycle includes: Fully charge and discharge multiple batteries; Obtain the discharge voltage-time curves corresponding to the full charge and discharge processes of multiple batteries; The overlapping portions of the multiple discharge voltage-time curves are identified as regular segments, and the differing portions of the multiple discharge voltage-time curves are identified as irregular segments.
2. The method for estimating battery capacity according to claim 1, characterized in that, The process of fully charging and discharging multiple batteries includes: Fully charge and discharge multiple batteries of different capacities.
3. The method for estimating battery capacity according to claim 1, characterized in that, Determining the first capacity corresponding to the rule segment includes: A curve function is fitted based on regular segments of the multiple discharge voltage-time curves; The first discharge time corresponding to the regular segment is determined based on the curve function and the boundary voltage. The first capacity corresponding to the rule segment is determined based on the discharge current corresponding to the rule segment and the first discharge time.
4. The method for estimating battery capacity according to claim 3, characterized in that, The curve fitting function based on the regular segments of the multiple discharge voltage-time curves includes: Multiple initial functions are fitted according to the regular segments of the multiple discharge voltage-time curves; The coefficients of the multiple initial functions are averaged to obtain the curve function.
5. The method for estimating battery capacity according to claim 4, characterized in that, The process of fitting multiple initial functions based on regular segments of the multiple discharge voltage-time curves includes: The following preset functions are used to fit multiple initial functions to the regular segments of the multiple discharge voltage-time curves respectively: ； in, This represents a preset function with time t as the independent variable and discharge voltage as the function value, where a, b, and c are coefficients.
6. The method for estimating battery capacity according to any one of claims 1-5, characterized in that, The step of discharging the battery under test, which has been charged to the charging cutoff voltage, and determining the corresponding second capacity includes: The battery under test, which has been charged to the charging cutoff voltage, is discharged, and the corresponding second discharge time is determined. The corresponding second capacity is determined based on the corresponding discharge current and the second discharge time.
7. The method for estimating battery capacity according to any one of claims 1-5, characterized in that, The method further includes: If the difference between the estimated capacity and the actual capacity of the battery under test is greater than a set threshold, the boundary voltage is adjusted, and the step of determining the boundary voltage corresponding to the boundary between the regular segment and the irregular segment is performed again.
8. A battery capacity estimation device, characterized in that, The battery capacity estimation device includes a processor and a memory, the memory being used to store program data, and the processor being used to execute the program data to implement the battery capacity estimation method as described in any one of claims 1-7.
9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores program data, which, when executed by a processor, is used to implement the battery capacity estimation method as described in any one of claims 1-7.