CN117647743B

CN117647743B - Battery capacity determining method, device, equipment and storage medium

Info

Publication number: CN117647743B
Application number: CN202410123282.8A
Authority: CN
Inventors: 段潘婷; 林文煜
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2024-01-30
Filing date: 2024-01-30
Publication date: 2024-06-07
Anticipated expiration: 2044-01-30
Also published as: CN117647743A

Abstract

The embodiment of the application discloses a method, a device, equipment and a storage medium for determining the battery capacity, wherein the method for determining the battery capacity comprises the following steps: acquiring historical charge and discharge data of a battery of electric equipment; determining at least two standing opportunity points from charge and discharge moments corresponding to historical charge and discharge data; screening the standing opportunity points in the at least two standing opportunity points based on a preset first screening condition to obtain at least one target standing opportunity point; determining a first accumulation sum of the accumulated ampere-hour integral capacity value of the battery cell at the target standing opportunity point and the accumulated ampere-hour integral capacity value in a period of time before and after the target standing opportunity point, and a second accumulation sum of the charge-discharge depth of the battery cell at the target standing opportunity point and the charge-discharge depth in a period of time before and after the target standing opportunity point; and determining the ratio between the first accumulation sum of the battery cells and the second accumulation sum of the corresponding battery cells as the health state value of the battery cells at the target standing opportunity point.

Description

Battery capacity determining method, device, equipment and storage medium

Technical Field

The present application relates to, but not limited to, the field of battery technologies, and in particular, to a method, an apparatus, a device, and a storage medium for determining a battery capacity.

Background

With the transition of the human energy consumption structure, renewable clean energy is attracting attention. Among them, some batteries (e.g., lithium batteries) have been widely used in the fields of pure electric vehicles and large-scale energy storage, etc., because of their advantages of high energy density, long cycle life, safe use, low self-discharge rate, etc. The prior art uses a Battery management system (Battery MANAGEMENT SYSTEM, BMS) to determine the operating state (remaining capacity) and service life of the Battery, and this may lead to inaccurate estimation of the Battery capacity because the quality of the BMS performance directly affects the operation quality of the power device.

Disclosure of Invention

In view of this, the embodiments of the present application provide a method, an apparatus, a device, and a storage medium for determining a battery capacity.

The technical scheme of the application is realized as follows:

in a first aspect, an embodiment of the present application provides a method for determining a battery capacity, where the method for determining a battery capacity includes:

acquiring historical charge and discharge data of a battery of electric equipment, wherein the battery comprises at least two battery cores, and the historical charge and discharge data comprises: the capacity information of the battery cell at least at two charge and discharge moments;

Determining at least two standing opportunity points from charge and discharge moments corresponding to the historical charge and discharge data;

Screening the standing opportunity points in the at least two standing opportunity points based on a preset first screening condition to obtain at least one target standing opportunity point; wherein the first screening condition relates to the charge capacity and discharge capacity of the battery cell;

Determining a first accumulation sum of an accumulated ampere-hour integral capacity value of the battery cell at the target standing opportunity point and an accumulated ampere-hour integral capacity value in a previous and subsequent period of time and a second accumulation sum of a charge-discharge depth of the battery cell at the target standing opportunity point and a charge-discharge depth in the previous and subsequent period of time aiming at the target standing opportunity point; and determining the ratio between the first accumulation sum of the electric core and the second accumulation sum of the corresponding electric core as the health state value of the electric core at the target standing opportunity point.

In the embodiment of the application, on one hand, the charge capacity and the discharge capacity of the battery core are utilized to screen the standing opportunity point in the at least two standing opportunity points to obtain at least one target standing opportunity point, so that the effectiveness of the target standing opportunity point can be ensured; on the other hand, in the process of determining the health state value of the battery cell at the target standing opportunity point, the accumulated sum of the accumulated ampere-hour integral capacity values and the accumulated sum of the charge and discharge depths of the battery cell in a period of time (for example, 30 days) before and after the moment of the target standing opportunity point are determined, so that the accuracy of the subsequent determination of the health state value of the battery cell at the target standing opportunity point can be improved.

In some embodiments, the screening the standing opportunity point of the at least two standing opportunity points based on the preset first screening condition to obtain at least one target standing opportunity point includes: according to historical charge and discharge data between two standing opportunity points in the at least two standing opportunity points, determining the charge capacity and discharge capacity of each battery cell between the two standing opportunity points; and reserving or deleting the two standing opportunity points based on the charge capacity and the discharge capacity of each cell.

According to the embodiment of the application, on one hand, according to the historical charge and discharge data between any two of at least two standing opportunity points, the charge capacity and discharge capacity of each battery cell between the two standing opportunity points are determined, so that the determination opportunity of each standing opportunity point is improved, and the number of determinable standing opportunity points is increased; on the other hand, based on the charge capacity and the discharge capacity of each battery cell, two standing opportunity points are reserved or deleted, so that the effectiveness of the standing opportunity points is ensured, and the accuracy of the subsequent determination of the health state value of the battery cell at the target standing opportunity point is improved.

In some embodiments, the reserving or deleting the two standing opportunity points based on the charge capacity and the discharge capacity of each cell includes: for each electric core, when the charging capacity of the electric core is larger than the battery capacity of a preset first target weight and the discharging capacity of the electric core is smaller than the battery capacity of a preset second target weight, reserving the two standing opportunity points, otherwise deleting the two standing opportunity points; wherein the first target weight is related to a charge capacity error and a vehicle coverage rate, and the second target weight is related to a discharge capacity error and a vehicle coverage rate.

In the embodiment of the application, if the battery capacity of the preset first target weight and the battery capacity of the preset second target weight are bothThe charging capacity of the battery core is larger than/>And the discharge capacity of the battery cell is smaller than/>And when the battery cell is in a target standing state, the two standing opportunity points are reserved, and otherwise, the two standing opportunity points are deleted, so that the effectiveness of the standing opportunity points is ensured, and the accuracy of the subsequent determination of the health state value of the battery cell at the target standing opportunity point is improved.

In some embodiments, the method for determining battery capacity further comprises: determining a first influence effect graph of different first weight coefficients on the charging capacity error and the vehicle coverage rate, wherein an abscissa is the first weight coefficient, and two ordinate are the charging capacity error and the vehicle coverage rate respectively; determining at least one charging capacity error under a preset first target vehicle coverage rate in the first influence effect graph; determining a first weight coefficient corresponding to the lowest charging capacity error among the at least one charging capacity error as a first target weight; or in the first influence effect graph, determining at least one vehicle coverage under a preset first target charging capacity error; and determining a first weight coefficient corresponding to the vehicle coverage rate with the highest at least one vehicle coverage rate as a first target weight.

In the embodiment of the present application, the first target weight is determined according to any one of the following two embodiments, and in one embodiment, if the preset first target vehicle coverage rate is 100%, the first weight coefficient corresponding to the lowest charge capacity error under the condition that the vehicle coverage rate is 100% is determined as the first target weight, so that the minimum charge capacity error corresponding to the first target weight can be ensured; in another embodiment, if the preset first target charging capacity error is less than 5%, the first weight coefficient corresponding to the highest vehicle coverage rate with the charging capacity error being less than 5% is determined as the first target weight, so that the highest vehicle coverage rate corresponding to the first target weight can be ensured.

In some embodiments, the method for determining battery capacity further comprises: determining a second influence effect graph of different second weight coefficients on the discharge capacity error and the vehicle coverage rate, wherein an abscissa is the second weight coefficient, and two ordinate are the discharge capacity error and the vehicle coverage rate respectively; determining at least one discharge capacity error under a preset second target vehicle coverage rate in the second influence effect graph; determining a second weight coefficient corresponding to the lowest discharge capacity error in the at least one discharge capacity error as a second target weight; or in the second influence effect graph, determining at least one vehicle coverage under a preset discharge capacity error; and determining a second weight coefficient corresponding to the highest vehicle coverage rate in the at least one vehicle coverage rate as a second target weight.

In the embodiment of the present application, the second target weight is determined according to any one of the following two embodiments, and in one embodiment, if the preset second target vehicle coverage rate is 100%, the second weight coefficient corresponding to the lowest discharge capacity error under the condition that the vehicle coverage rate is 100% is determined as the second target weight, so that the minimum discharge capacity error corresponding to the second target weight can be ensured; in another embodiment, if the preset discharge capacity error is less than 5%, the second weight coefficient corresponding to the highest vehicle coverage rate with the preset discharge capacity error being less than 5% is determined as the second target weight, so that the highest vehicle coverage rate corresponding to the second target weight can be ensured.

In some embodiments, determining a depth of charge and discharge of a cell at the target point of opportunity for rest for the target point of opportunity comprises: determining the starting time and the ending time of the historical discharge data corresponding to the target standing opportunity point; for each electric core, based on the voltage of the electric core at the starting moment, inquiring a State of Charge (SOC) -open circuit voltage (Open Circuit Voltage, OCV) mapping relation table, and determining the SOC value of the electric core at the starting moment; for each battery cell, inquiring a state of charge (SOC) -Open Circuit Voltage (OCV) mapping relation table based on the voltage of the battery cell at the end time, and determining the SOC value of the battery cell at the end time; and for each battery cell, determining the difference between the SOC value of the battery cell at the starting moment and the SOC value of the corresponding battery cell at the ending moment as the charge and discharge depth of the corresponding battery cell at the target standing opportunity point.

According to the embodiment of the application, the difference between the SOC value of the battery cell at the starting time and the SOC value of the corresponding battery cell at the ending time is determined as the charge and discharge depth of the corresponding battery cell at the target standing opportunity point, so that the accuracy of the charge and discharge depth of the battery cell at the target standing opportunity point is improved, and the accuracy of the subsequent determination of the health state value of the battery cell at the target standing opportunity point is improved.

In some embodiments, the determining at least two standing opportunity points from the charge-discharge moments corresponding to the historical charge-discharge data includes: and determining at least two standing opportunity points from charging and discharging moments corresponding to the historical charging and discharging data based on a preset second screening condition, wherein the second screening condition is set for the discharging current of the battery cell and the continuous discharging duration under the discharging current.

In the embodiment of the application, at least two standing opportunity points are determined from the charging and discharging moments corresponding to the historical charging and discharging data based on the preset second screening conditions, so that the effectiveness of the standing opportunity points is ensured, and the accuracy of the subsequent determination of the health state value of the battery cell at the target standing opportunity point is improved.

In a second aspect, an embodiment of the present application provides a device for determining a battery capacity, including:

the device comprises an acquisition module, a storage module and a control module, wherein the acquisition module is used for acquiring historical charge and discharge data of a battery of electric equipment, the battery comprises at least two battery cores, and the historical charge and discharge data comprises: the capacity information of the battery cell at least at two charge and discharge moments;

The first determining module is used for determining at least two standing opportunity points from the charging and discharging moments corresponding to the historical charging and discharging data;

The screening module is used for screening the standing opportunity points in the at least two standing opportunity points based on a preset first screening condition to obtain at least one target standing opportunity point; wherein the first screening condition relates to the charge capacity and discharge capacity of the battery cell;

The second determining module is used for determining a first accumulation sum of the accumulated ampere-hour integral capacity value of the battery cell at the target standing opportunity point and the accumulated ampere-hour integral capacity value in a previous and subsequent period and a second accumulation sum of the charge and discharge depth of the battery cell at the target standing opportunity point and the charge and discharge depth in the previous and subsequent period aiming at the target standing opportunity point;

and the third determining module is used for determining the ratio between the first accumulation sum of the battery cells and the second accumulation sum of the corresponding battery cells as the health state value of the battery cells at the target standing opportunity point.

In a third aspect, an embodiment of the present application provides a computer device, including a memory, a processor, and a computer program stored in the memory, where the processor implements some or all of the steps in the above method for determining a battery capacity when executing the computer program.

In a fourth aspect, embodiments of the present application provide a computer-readable storage medium having stored thereon a computer program or instructions which, when executed by a processor, implement some or all of the steps in the above-described method of determining battery capacity.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application.

Fig. 1 is a schematic implementation flow chart of a method for determining battery capacity according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a first weight coefficient versus charge capacity error and versus vehicle coverage for a vehicle according to an embodiment of the present application;

FIG. 3 is a schematic diagram showing a second weight coefficient versus discharge capacity error and vehicle coverage ratio according to an embodiment of the present application;

Fig. 4 is a schematic implementation flow chart of another method for determining battery capacity according to an embodiment of the present application;

fig. 5 is a schematic diagram of a composition structure of a battery capacity determining device according to an embodiment of the present application;

Fig. 6 is a schematic diagram of a hardware entity of a computer device according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application more apparent, the specific technical solutions of the present application will be described in further detail below with reference to the accompanying drawings in the embodiments of the present application. The following examples are illustrative of the application and are not intended to limit the scope of the application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of the application only and is not intended to be limiting of the application.

In the following description reference is made to "some embodiments," "this embodiment," "an embodiment of the application," and examples, etc., which describe a subset of all possible embodiments, but it is to be understood that "some embodiments" may be the same subset or different subsets of all possible embodiments and may be combined with one another without conflict.

If a similar description of "first/second" appears in the application document, the following description is added, in which the terms "first/second/third" are merely distinguishing between similar objects and not representing a particular ordering of the objects, it being understood that the "first/second/third" may be interchanged with a particular order or precedence, if allowed, so that embodiments of the application described herein may be practiced otherwise than as illustrated or described herein.

In order to facilitate understanding of the embodiments of the present application, a technical solution related to the embodiments of the present application and drawbacks of the technical solution will be briefly described below.

The battery state mainly includes two most important aspects: the State of charge of the power cell and the State of Health (SOH) of the power cell.

The state of charge of the power cell refers to: the available state of the residual charge in the battery can reflect the current residual quantity of the power battery, is an important precondition for realizing the energy balance technology of the ternary lithium battery pack, and is one of the most important parameters in BMS monitoring.

The state of charge of a power cell is often defined by the following equation: soc= (Q _{Residual of}/Q_{Rated for}) ×100%, where Q _{Rated for} represents the rated charge capacity of the power battery; q _{Residual of} represents the remaining charge balance in the power cell.

The state of health of the power cell refers to: the percentage of the full charge capacity of the power battery relative to the rated capacity can reflect the current service life of the power battery, which is also called the aging degree of the power battery, and the size of the health state value of the power battery generally directly determines whether the electric equipment needs to be subjected to the operation of ternary lithium battery replacement. Generally, the state of health of a power cell of a new power cell is 100%.

In the prior art, when estimating the state of charge and the state of health of a battery, a method of a Dai Weining (Thevenin) equivalent circuit model is generally adopted, and a state space equation of the improved Thevenin equivalent circuit model is obtained according to a circuit relation; and further obtains the mapping relation between the open circuit voltage and the state of charge of the power battery. A battery with forgetting factor recursive least square method (Forgetting Factor Recursive Least Square, FFRLS) is utilized to acquire external voltage current values, and specific values of polarization resistance, polarization capacitance and internal resistance at each sampling point are obtained through real-time identification; and updating the parameter value of the Thevenin equivalent circuit model in real time according to the running state of the battery management system at the moment before calculating the state of charge of the battery and the state of health of the battery each time, so that the prediction of the BMS on the state of charge of the battery and the state of health of the battery is ensured.

Although, the method is relatively complex in calculation and requires high calculation force aiming at the equivalent circuit model adopted when the ternary lithium battery SOC and SOH are estimated, and for background large-batch project application, the number of the electric cores of each project is hundreds, so that the method is difficult to be practically applied.

Based on this, the embodiment of the present application provides a method for determining a battery capacity, as shown in fig. 1, the method for determining a battery capacity may include the following steps S101 to S105, where:

step S101, historical charge and discharge data of a battery of electric equipment is obtained, the battery comprises at least two battery cores, and the historical charge and discharge data comprises: the capacity information of the battery cell at least at two charge and discharge moments;

Here, the electric device may be a device for converting electric energy into other forms of energy, for example, an electronic device having a power battery, such as an electric automobile, an aircraft, a ship, an electric bicycle, etc., and the embodiment of the present application does not limit the type of the electric device. The capacity information of the battery cell comprises a current value of the battery cell, a maximum voltage value of the battery cell, a minimum voltage value of the battery cell, a maximum voltage battery cell position, a minimum voltage battery cell position, electric quantity of the battery cell, a voltage value of the battery cell, mileage of the battery cell, a charge/discharge zone bit (1 is discharge, 0 is charge) of the battery cell and the like.

In some embodiments, the capacity information of at least two battery cores of the electric equipment at least two charging and discharging moments is obtained, so that the time consumed for determining the standing opportunity point from the charging and discharging moments is saved.

Step S102, determining at least two standing opportunity points from charge and discharge moments corresponding to the historical charge and discharge data;

Here, the standing opportunity point means: and when the discharge current in the historical charge and discharge data of the battery core is a first preset value and the discharge time lasts for more than the first preset duration, the historical charge and discharge data of the last charge and discharge time are obtained. For example, for an electric vehicle with a ternary lithium battery, the first preset value may be ±5a, and the first preset period of time may be 10 minutes; here, 5A and 10 minutes are set according to empirical data, mainly related to depolarization, for example, the discharge current at the cell is 5A and polarization can be guaranteed to be dropped for 10 minutes.

The depolarization process of the cell refers to: after the battery is discharged to a certain stage according to the current with a certain multiplying power, the discharging is stopped, and after the battery is placed for a certain period of time, for example, 30 minutes, the cell of the battery is depolarized in the period of time, that is, the terminal voltage of the target battery slowly changes in the period of 30 minutes until the battery reaches a stable state, and the terminal voltage value of the battery in the depolarization can change along with the time to form a voltage change curve.

Thus, the first preset duration in the embodiment of the present application refers to: the turning point of the voltage value at the end of the battery in 30 minutes of depolarization tends to be gentle is defined as T1, and it is understood that the value of T1 varies with the performance of the battery, and if the electric core of the battery is of a type with fast depolarization, for example, lithium carbonate, potassium manganate, ternary material lithium ion battery and the like, the T1 can be taken as 10 minutes, that is, after 10 minutes of depolarization of the battery, the end voltage value can reach a stable state.

The discharging current range of the battery cell is related to the battery cell capacity, the architecture of the battery pack (single-branch or double-branch), and the charging speed type (fast charge or full charge). Under the condition that the battery cells are connected in series, the discharge current range of the battery cells is +/-100A, namely, the discharge current range of each battery cell is +/-100A. In addition, the first preset value and the first preset duration may be different for different powered devices.

Step S103, screening the standing opportunity points in the at least two standing opportunity points based on a preset first screening condition to obtain at least one target standing opportunity point; wherein the first screening condition relates to the charge capacity and discharge capacity of the battery cell;

here, the preset first screening condition refers to: charging capacity of battery cell And the discharge capacity of the battery cell. Wherein C0 represents the nominal capacity of the cell, which refers to: the nominal capacity of the battery cell can be checked by a label or a product specification of the battery cell, which is a standard value set by a battery manufacturer when manufacturing the battery.

In some embodiments, the target resting opportunity point refers to: the charging capacity of the battery core is larger thanAnd the discharge capacity of the battery cell is greater than/>Is a stationary opportunity point of the (c).

The charge capacity of the battery cell can be calculated by the following formula (1):

（1）；

Wherein, charge_cap represents the charge capacity of the battery cell; the subscript S1 represents the start time of the historical charging data; the upper corner mark E1 indicates the end time of the history charge data; the time interval represents the time interval between two adjacent historical charging data, in units of: second(s).

The discharge capacity of the cell can be calculated by the following formula (2):

（2）；

Wherein, discharge_cap represents the discharge capacity of the cell; the subscript S2 denotes the start time of the history discharge data; the upper corner mark E2 indicates the end time of the history discharge data; the time interval represents a time interval between adjacent two of the history discharge data.

Step S104, aiming at the target standing opportunity point, determining a first accumulation sum of accumulated ampere-hour integral capacity values of the battery cells at the target standing opportunity point and accumulated ampere-hour integral capacity values in a previous and later period and a second accumulation sum of charge and discharge depths of the battery cells at the target standing opportunity point and charge and discharge depths in the previous and later period;

Here, the charge-discharge depth (Depth of discharge, DOD) of the cell refers to: the extent to which a battery is discharged in a fully charged state is generally expressed in terms of a percentage of the remaining charge.

In some embodiments, if the time at which the target rest opportunity point of the cell is located is the i-th time, the period of time before and after refers to: the first 14 days and the last 14 days of the ith moment. The front and back 14 days are artificially and subjectively set thresholds, which mainly consider that the cell capacity remains substantially unchanged within one month.

Step S105, determining a ratio between the first accumulated sum of the battery cells and the second accumulated sum of the corresponding battery cells as a health status value of the battery cells at the target standing opportunity point.

Here, the SOH value of the cell at the target rest opportunity point means: the SOH value of the newly shipped battery is 100% as a percentage of the full charge capacity of the battery to the rated capacity.

The health state value of the battery cell at the target standing opportunity point can be calculated by the following formula (3):

（3）；

SOH _i represents the health state value of the battery cell at the target standing opportunity point; Representing a first accumulated sum of the accumulated ampere-hour integral capacity value of the battery cell at the target standing opportunity point and the accumulated ampere-hour integral capacity value in the previous and subsequent 14 days; /(I) And a second summation of the charge and discharge depth of the battery cell at the target standing opportunity point and the charge and discharge depth within 14 days before and after the battery cell.

The cumulative ampere-hour integral capacity value of the cell can be calculated by the following formula (4):

cap=charge_cap+discharge_cap （4）；

Wherein cap represents the cumulative ampere-hour integral capacity value of the battery cell.

The charge and discharge depth of the battery cell can be calculated by the following formula (5):

Dod=electric quantity value at the end time of the history discharge data-electric quantity value at the start time of the history discharge data (5);

wherein DOD represents the charge and discharge depth of the battery cell.

In some embodiments, the step S103 "screening the standing opportunity points of the at least two standing opportunity points based on the preset first screening condition, and obtaining the at least one target standing opportunity point" may include the following steps S1031 and S1032, where:

step S1031, determining the charge capacity and the discharge capacity of each battery cell between two rest opportunity points according to historical charge and discharge data between the two rest opportunity points in the at least two rest opportunity points;

In some embodiments, two standing opportunity points are arbitrarily combined, the charge capacity of each cell between the two standing opportunity points is determined by the above formula (1) according to the historical charge-discharge data between any two standing opportunity points, and the discharge capacity of each cell between the two standing opportunity points is determined by the above formula (2).

The charge capacity and discharge capacity of the cells were all calculated using ampere-hour integration, and the current flowing through all the cells was the same, so that the charge capacity and discharge capacity of all the cells were the same.

Step S1032, based on the charge capacity and discharge capacity of each of the battery cells, the two standing opportunity points are reserved or deleted.

Here, the standing opportunity corresponding to the charging capacity of the battery cell by using the preset battery capacity of the first target weight, and the standing opportunity point corresponding to the discharging capacity of the battery cell by using the preset battery capacity of the second target weight are reserved or deleted. It should be noted that, the battery capacity of the preset first target weight may be the same as or different from the battery capacity of the preset second target weight.

In some embodiments, if the battery capacity of the preset first target weight and the battery capacity of the preset second target weight are bothThe charging capacity of the battery core is larger than/>And the discharge capacity of the battery cell is smaller than/>Reserving corresponding standing opportunity points; correspondingly, the rest opportunity point corresponding to any one of the following three conditions is deleted: case 1, cell charge capacity greater than/>And the discharge capacity of the battery cell is greater than/>; Case 2, the charge capacity of the cell is less than/>And the discharge capacity of the battery cell is smaller than/>; Case 3, the charge capacity of the cell is less than/>And the discharge capacity of the battery cell is greater than/>。

In some embodiments, the implementation of step S1032 "to reserve or delete the two opportunity points for rest based on the charge capacity and the discharge capacity of each of the battery cells" may include the following step S10321, wherein:

Step S10321, for each of the electric cores, when the charging capacity of the electric core is greater than the battery capacity of the preset first target weight and the discharging capacity of the electric core is less than the battery capacity of the preset second target weight, reserving the two standing opportunity points, otherwise, deleting the two standing opportunity points;

Here, the first target weight is related to the charge capacity error and the coverage of the vehicle, and the second target weight is related to the discharge capacity error and the coverage of the vehicle.

In some embodiments, if the first target weight is set to 0.3, the battery capacity of the preset first target weight is. Thus, the charge capacity at the cell is greater than/>And the discharge capacity of the battery cell is smaller than/>And reserving the two rest opportunity points, and deleting the two rest opportunity points if not.

In some embodiments, the method for determining a battery capacity further includes the following steps S111a and S112a, wherein:

step S111a, determining a first influence effect graph of different first weight coefficients on the charging capacity error and the vehicle coverage rate, wherein an abscissa is the first weight coefficient, and two ordinate are the charging capacity error and the vehicle coverage rate respectively;

Here, as shown in fig. 2, the first influence diagram is shown in fig. 2, and it can be seen that the abscissa (0 to 0.7) is the first weight coefficient, the ordinate (0 to 120) on the left side of fig. 2 is the vehicle coverage, and the ordinate (0 to 30) on the right side of fig. 2 is the charge capacity error.

When the first weight coefficient is 0.1 or 0.2 or 0.3, the vehicle coverage rate is highest and is 100%, and the charging capacity error is reduced from 25% to within 5%; when the first weight coefficient is greater than 0.3 and less than or equal to 0.6, although the charge capacity error is maintained within 5%, the vehicle coverage rate is reduced from 100% to 10%, severely affecting the vehicle coverage rate.

Step S112a, in the first influence effect diagram, determining at least one charge capacity error under a preset first target vehicle coverage rate; and determining a first weight coefficient corresponding to the lowest charging capacity error among the at least one charging capacity error as a first target weight.

As can be seen from fig. 2, if the preset first target vehicle coverage is 100%, the charge capacity error may be 25%, 10% and 4%; the first weight coefficient corresponding to the vehicle coverage rate of 100% and the charge capacity error of 4% is determined as the first target weight of 0.3.

In some embodiments, the method for determining a battery capacity further includes the following step S111b and step S112b, wherein:

Step S111b, determining a first influence effect graph of different first weight coefficients on the charging capacity error and the vehicle coverage rate, wherein an abscissa is the first weight coefficient, and two ordinate are the charging capacity error and the vehicle coverage rate respectively;

Step S112b, in the first influence effect diagram, determining at least one vehicle coverage under a preset first target charging capacity error; and determining a first weight coefficient corresponding to the vehicle coverage rate with the highest at least one vehicle coverage rate as a first target weight.

As can be seen from fig. 2, if the preset first target charge capacity error is 5% or less, the vehicle coverage rate may be 100%, 80%, 50% and 40%; therefore, the first weight coefficient corresponding to the charging capacity error of 5% or less and the vehicle coverage of 100% is determined as the first target weight.

In some embodiments, the method for determining a battery capacity further includes the following steps S121a and S122a, wherein:

Step S121a, determining a second influence effect graph of different second weight coefficients on the discharge capacity error and the vehicle coverage rate, wherein an abscissa is the second weight coefficient, and two ordinate are the discharge capacity error and the vehicle coverage rate respectively;

here, as shown in fig. 3, as can be seen from fig. 3, the abscissa (0 to 1) is the second weight coefficient, the ordinate (0 to 120) on the left of fig. 3 is the vehicle coverage, and the ordinate (0 to 40) on the right of fig. 3 is the discharge capacity error.

When the second weight coefficient is 0.1 to 0.3, the vehicle coverage rate is increased from 60% to 80%, and the discharge capacity error is maintained within 5%; when the second weight coefficient is 0.3 or more and 0.9 or less, although the vehicle coverage rate is first increased from 80% to 100%, the discharge capacity error is increased from 5% or less to 37%, severely affecting the discharge capacity error.

Step S122a, in the second effect graph, determining at least one discharge capacity error under a preset second target vehicle coverage; and determining a second weight coefficient corresponding to the lowest discharge capacity error in the at least one discharge capacity error as a second target weight.

As can be seen from fig. 3, if the preset second target vehicle coverage is 100%, the discharge capacity errors may be 17%, 22%, 24%, 27% and 37%; the second weight coefficient corresponding to the vehicle coverage of 100% and the discharge capacity error of 17% was determined as the second target weight of 0.5.

In some embodiments, the method for determining a battery capacity further includes the following steps S121b and S122b, wherein:

Step S121b, determining a second influence effect graph of different second weight coefficients on the discharge capacity error and the vehicle coverage rate, wherein an abscissa is the second weight coefficient, and two ordinate are the discharge capacity error and the vehicle coverage rate respectively;

Step S122b, in the second effect graph, determining at least one vehicle coverage under a preset discharge capacity error; and determining a second weight coefficient corresponding to the highest vehicle coverage rate in the at least one vehicle coverage rate as a second target weight.

As can be seen from fig. 3, if the preset discharge capacity error is 5% or less, the vehicle coverage may be 60%, 78% and 80%; therefore, the second weight coefficient corresponding to the discharge capacity error of 5% or less and the vehicle coverage of 80% is determined as the second target weight of 0.3.

In some embodiments, the implementation of "determining the charge-discharge depth of the battery cell at the target rest opportunity point for the target rest opportunity point" in step S104 may include the following steps S131 to S134, wherein:

Step S131, determining the starting time and the ending time of the historical discharge data corresponding to the target standing opportunity point;

Step S132, for each electric core, based on the voltage of the electric core at the starting time, inquiring a state of charge (SOC) -Open Circuit Voltage (OCV) mapping relation table, and determining the SOC value of the electric core at the starting time;

here, the SOC-open circuit voltage OCV mapping tables of the battery cells may be different for the battery cells of different electric devices, and thus, in determining the SOC value of the battery cell, the SOC-open circuit voltage OCV mapping table of the battery cell should be selected.

Step S133, for each electric core, based on the voltage of the electric core at the end time, inquiring a state of charge (SOC) -Open Circuit Voltage (OCV) mapping relation table, and determining the SOC value of the electric core at the end time;

Step S134, for each of the electric cells, determining a difference between the SOC value of the electric cell at the start time and the SOC value of the corresponding electric cell at the end time as a charge/discharge depth of the corresponding electric cell at the target standing opportunity point.

Here, the SOC value of the battery cell at the start time refers to: the electric quantity value at the beginning of the historical discharge data in the above formula (5); the SOC value of the cell at the end time is: the electric quantity value at the end time of the history discharge data in the above formula (5).

In some embodiments, the implementation of step S102 "determining at least two opportunity points for rest from the charge-discharge moments corresponding to the historical charge-discharge data" may include the following step S1021, where:

step S1021, determining at least two standing opportunity points from the charge-discharge time corresponding to the historical charge-discharge data based on a preset second screening condition, where the second screening condition is set for the discharge current of the battery cell and the duration of discharge under the discharge current.

Here, the preset second screening condition may be that the discharge current of the battery cell is ±5a, and the discharge time of the battery cell lasts for more than 10 minutes.

In some embodiments, if 1000 rows of data from 2023/11/10:30:20 to 2023/11/10:11:00:00 in the historical charge-discharge data satisfy the discharge current of the cell to + -5A, the discharge time of the cell lasts for 10 minutes, the 1000 th row of data is determined as a rest opportunity point.

In the embodiment of the application, at least two standing opportunity points are determined from the charging and discharging moments corresponding to the historical charging and discharging data based on the preset second screening conditions, so that the effectiveness of the standing opportunity points is ensured, and the accuracy of the health state value of the battery cell at the target standing opportunity point is improved.

The embodiment of the application provides another method for determining the battery capacity, which can solve the following two technical problems: technical problem 1: aiming at the actual running data working conditions of the real vehicles corresponding to the ternary batteries, the static working conditions are few, so that the coverage rate of the vehicles is low when SOH is calculated, and the computer points of each vehicle are few. Technical problem 2: aiming at the actual running data working condition of the real vehicle corresponding to the ternary battery, the data acquisition frequency is low, so that the computer opportunity point fluctuation is larger.

The battery generally has a standing condition, a discharging condition and a charging condition, wherein the charging condition refers to a process of charging the battery to a charging cut-off voltage, the discharging condition refers to a process of discharging the battery to the discharging cut-off voltage, and the standing condition refers to a process of neither discharging nor charging the battery.

The embodiment of the application provides another method for determining the capacity of a battery, which comprises the steps of firstly, introducing a small number of discharging sections of the battery to obtain more standing opportunity points from charging and discharging moments corresponding to historical charging and discharging data of the battery, and secondly, randomly combining any two standing opportunity points in a plurality of standing opportunity points and determining the charging capacity, the discharging capacity and the discharging depth between the any two standing opportunity points, so that the determination opportunity of each standing opportunity point is improved, and the number of determinable standing opportunity points is further improved; in yet another aspect, by determining the health status values of two opportunity points of rest in any random combination, the accuracy of the health status values of the cells at the target opportunity point of rest can be improved.

The embodiment of the application provides another method for determining the battery capacity, as shown in fig. 4, which includes the following steps:

Step S401, historical charge and discharge data of a ternary lithium battery vehicle are obtained;

step S402, preprocessing historical charge and discharge data to obtain preprocessed historical charge and discharge data;

Step S403, extracting a standing opportunity point of the battery from the preprocessed historical charge and discharge data;

step S404, obtaining an SOC value corresponding to a standing opportunity point of the battery;

Step S405, dynamically searching standing opportunity points of each battery;

in step S406, SOH value at each opportunity point of standing is calculated.

In step S401, historical charge and discharge data of the ternary lithium battery vehicle and basic parameter information (a battery cell nominal capacity C0 and a battery cell soc_ocv map) of a battery cell of the ternary lithium battery are obtained.

The historical charge and discharge data of the ternary lithium battery vehicle are shown in tables 1-1 and 1-2, and the historical charge and discharge data comprises field name time, current, maximum voltage, minimum voltage, maximum voltage cell position, minimum voltage cell position, electric quantity, detailed cell voltage (cell voltage is mV) mileage and charge and discharge zone bit (1 is discharge and 0 is charge).

TABLE 1-1

TABLE 1-2

The soc_ocv map table is shown in table 2, and the SOC value and OCV value in the soc_ocv map table may be different for different cell systems.

TABLE 2

In step S402, the null value in the historical charge-discharge data is deleted, the row is repeated, and the abnormal value data is obtained, thereby obtaining the preprocessed historical charge-discharge data.

In step S403, at least two standing opportunity points are screened from the charge-discharge time corresponding to the preprocessed historical charge-discharge data according to a preset second screening condition. Wherein, the second screening condition is: the discharge current of the battery core is + -5A, and the duration of discharge under the discharge current is more than 10 minutes. The 5A and 10 minutes are empirically determined, mainly in relation to depolarization, and a 5A current lasting 10 minutes ensures depolarization.

For example, if there are 1000 lines of historical charge and discharge data between the time ranges 2023/11/10:30:20 to 2023/11/10:00:00, the 1000 lines of historical charge and discharge data are referred to as fragments, and the historical charge and discharge data at the last time point in the time range are regarded as standing opportunity points.

The discharging current range of the battery cell is related to the battery cell capacity, the architecture of the battery pack (single-branch or double-branch), and the charging speed type (fast charge or full charge). Under the condition that the battery cells are connected in series, the discharge current range of the battery cells is +/-100A, namely the discharge current of each battery cell is the same.

In step S404, according to the detailed cell voltage of the standing opportunity point of the cell, the soc_ocv mapping relation table of the cell is checked, so as to obtain a real SOC value corresponding to each cell voltage.

In step S405, two standing opportunity points are arbitrarily combined, and charging data and discharging data can be obtained according to the historical charging and discharging data and the charging flag bit between the two standing opportunity points.

（1）；

（2）；

Wherein, discharge_cap represents the discharge capacity of the cell; the subscript S2 denotes the start time of the history discharge data; the upper corner mark E2 indicates the end time of the history discharge data; the time interval represents the time interval between two adjacent historic discharge data in units of: second(s).

cap=charge_cap+discharge_cap （4）；

wherein DOD represents the charge and discharge depth of the battery cell.

If the charging capacity of the battery cell and the discharging capacity of the battery cell meet a preset first screening condition, reserving a standing opportunity point of the computer;

The preset first screening conditions are as follows: charging capacity of battery cell Discharge capacity of battery cell. The first target weight 0.3 is determined according to the influence of different first weight coefficients on SOH precision (the difference between the SOH error and the actual SOH represented by the calculated SOH) and the result of vehicle coverage rate, and the vehicle calculation coverage rate is highest under the condition that the charge capacity error or the discharge capacity error rate is ensured to be small as much as possible.

The first effect graphs of different first weight coefficients on the charging capacity error and the vehicle coverage rate are shown in fig. 2, and as can be seen from fig. 2, when the first weight coefficient is 0.1 or 0.2 or 0.3, the vehicle coverage rate is highest and is 100%, and the charging capacity error is reduced from 25% to within 5%; when the first weight coefficient is greater than 0.3 and less than or equal to 0.6, although the charge capacity error is maintained within 5%, the vehicle coverage rate is reduced from 100% to 10%, severely affecting the vehicle coverage rate. Thus, when the first weight coefficient is 0.3, the charging capacity error is low and the vehicle coverage is highest, and therefore, 0.3 is determined as the first target weight.

The second effect of the different second weight coefficients on the discharge capacity error and the vehicle coverage rate is shown in fig. 3, and it can be seen from fig. 3 that when the second weight coefficient is 0.1 to 0.3, the vehicle coverage rate is increased from 60% to 80%, and the discharge capacity error is maintained within 5%; when the second weight coefficient is 0.3 or more and 0.9 or less, although the vehicle coverage rate is first increased from 80% to 100%, the discharge capacity error is increased from 5% or less to 37%, severely affecting the discharge capacity error. Thus, when the second weight coefficient is 0.3, the charge capacity error is the lowest, and the vehicle coverage is high, and therefore, 0.3 is determined as the second target weight.

In step S406, the sum of the cumulative ampere-hour integral capacity value of the current time i at each standing opportunity point and the cumulative ampere-hour integral capacity value of 14 days before and after the current time i at each standing opportunity point is calculated and divided by the sum of the DOD of the current time i at each standing opportunity point and the DOD of 14 days before and after the current time i at each standing opportunity point to obtain the SOH value of the current time i at each standing opportunity point. The front and back 14 days are artificially and subjectively set thresholds, which mainly consider that the cell capacity remains substantially unchanged within one month.

（3）；

SOH _i represents the health state value of the battery cell at the target standing opportunity point; representing a first accumulated sum of the accumulated ampere-hour integral capacity value of the battery cell at the target standing opportunity point and the accumulated ampere-hour integral capacity value in the previous and subsequent 14 days; and a second summation of the charge and discharge depth of the battery cell at the target standing opportunity point and the charge and discharge depth within 14 days before and after the battery cell.

The experimental verification results of another method for determining the battery capacity according to the embodiment of the present application are shown in table 3, and it can be seen from table 3 that the accuracy of the SOH value calculated by the method is ±3%.

TABLE 3 Table 3

Compared with the prior art, the embodiment of the application has the following advantages:

1) The SOH value calculation method adopted by the embodiment of the application is simple, and complex decoupling and more calculation force resources are not needed;

2) The SOH value calculation method adopted by the embodiment of the application has higher vehicle coverage rate;

3) The SOH value calculation method adopted by the embodiment of the application has higher calculation precision;

4) According to the embodiment of the application, the calculation accuracy of the SOH value can be effectively improved, so that the purpose of evaluating the health state of the battery is achieved.

An embodiment of the present application provides a device for determining a battery capacity, as shown in fig. 5, a device 500 for determining a battery capacity includes: the obtaining module 510 is configured to obtain historical charge and discharge data of a battery of an electric device, where the battery includes at least two electric cells, and the historical charge and discharge data includes: the capacity information of the battery cell at least at two charge and discharge moments; a first determining module 520, configured to determine at least two standing opportunity points from charging and discharging moments corresponding to the historical charging and discharging data; a screening module 530, configured to screen the standing opportunity points of the at least two standing opportunity points based on a preset first screening condition, so as to obtain at least one target standing opportunity point; wherein the first screening condition relates to the charge capacity and discharge capacity of the battery cell; a second determining module 540, configured to determine, for the target standing opportunity point, a first cumulative sum of a cumulative ampere-hour integral capacity value of the battery cell at the target standing opportunity point and a cumulative ampere-hour integral capacity value in a previous and subsequent period, and a second cumulative sum of a charge-discharge depth of the battery cell at the target standing opportunity point and a charge-discharge depth in the previous and subsequent period; a third determining module 550, configured to determine a ratio between the first accumulated sum of the battery cells and the second accumulated sum of the corresponding battery cells as a health status value of the battery cells at the target standing opportunity point.

In some embodiments, the screening module 530 includes: the first determining submodule is used for determining the charge capacity and the discharge capacity of each battery cell between two rest opportunity points according to historical charge and discharge data between the two rest opportunity points in the at least two rest opportunity points; and the retaining or deleting sub-module is used for retaining or deleting the two standing opportunity points based on the charging capacity and the discharging capacity of each battery cell.

In some embodiments, the reserving or deleting sub-module is further configured to reserve, for each of the electrical cores, the two standing opportunity points if the charging capacity of the electrical core is greater than the battery capacity of the preset first target weight and the discharging capacity of the electrical core is less than the battery capacity of the preset second target weight, and otherwise delete the two standing opportunity points; wherein the first target weight is related to a charge capacity error and a coverage rate of the vehicle, and the second target weight is related to a discharge capacity error and a coverage rate of the vehicle.

In some embodiments, the battery capacity determining apparatus 500 further includes: a fourth determining module, configured to determine a first effect graph of different first weight coefficients on the charge capacity error and on the vehicle coverage rate, where an abscissa is the first weight coefficient, and two abscissas are the charge capacity error and the vehicle coverage rate respectively; a fifth determining module, configured to determine, in the first impact effect map, at least one charging capacity error under a preset first target vehicle coverage rate; determining a first weight coefficient corresponding to the lowest charging capacity error among the at least one charging capacity error as a first target weight; or a sixth determining module, configured to determine, in the first impact effect map, at least one vehicle coverage under a preset first target charging capacity error; and determining a first weight coefficient corresponding to the vehicle coverage rate with the highest at least one vehicle coverage rate as a first target weight.

In some embodiments, the battery capacity determining apparatus 500 further includes: a seventh determining module, configured to determine a second effect graph of different second weight coefficients on the discharge capacity error and on the vehicle coverage, where an abscissa is the second weight coefficient, and two ordinate are the discharge capacity error and the vehicle coverage respectively; an eighth determining module, configured to determine, in the second impact effect map, at least one discharge capacity error under a preset second target vehicle coverage rate; determining a second weight coefficient corresponding to the lowest discharge capacity error in the at least one discharge capacity error as a second target weight; or a ninth determining module, configured to determine, in the second impact effect graph, at least one vehicle coverage under a preset discharge capacity error; and determining a second weight coefficient corresponding to the highest vehicle coverage rate in the at least one vehicle coverage rate as a second target weight.

In some embodiments, the second determining module 540 includes: the second determining submodule is used for determining the starting time and the ending time of the historical discharge data corresponding to the target standing opportunity point; a third determining submodule, configured to query a SOC-open circuit voltage OCV mapping table for each of the electrical cores based on a voltage of the electrical core at the start time, and determine an SOC value of the electrical core at the start time; a fourth determining submodule, configured to query a SOC-open circuit voltage OCV mapping table for each of the electrical cores based on a voltage of the electrical core at the end time, and determine an SOC value of the electrical core at the end time; and a fifth determining submodule, configured to determine, for each of the electric cells, a difference between an SOC value of the electric cell at the start time and an SOC value of the corresponding electric cell at the end time, as a charge-discharge depth of the corresponding electric cell at the target standing opportunity point.

In some embodiments, the first determining module 520 is further configured to determine at least two opportunity points for standing from the charge-discharge time corresponding to the historical charge-discharge data based on a preset second screening condition, where the second screening condition is set for a discharge current of the battery cell and a duration of discharge under the discharge current.

In the embodiment of the present application, if the method for determining the battery capacity is implemented in the form of a software functional module and sold or used as a separate product, the method may also be stored in a computer readable storage medium. Based on such understanding, the technical solution of the embodiments of the present application may be essentially or some of contributing to the related art may be embodied in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read Only Memory (ROM), a magnetic disk, an optical disk, or other various media capable of storing program codes. Thus, embodiments of the application are not limited to any specific hardware, software, or firmware, or any combination of hardware, software, and firmware.

The embodiment of the application also provides a computer device which comprises a memory, a processor and a computer program stored on the memory, wherein when the processor executes the computer program, part or all of the steps in the method for determining the battery capacity are realized.

Embodiments of the present application also provide a computer-readable storage medium having stored thereon a computer program or instructions which, when executed by a processor, implement some or all of the steps in the above-described method of determining battery capacity. The computer readable storage medium may be transitory or non-transitory.

The embodiment of the application also provides a computer program, which comprises computer readable codes, wherein when the computer readable codes run in a computing device, a processor in the computing device executes part or all of the steps in the method for determining the capacity of the battery.

It should be noted here that: the above description of various embodiments is intended to emphasize the differences between the various embodiments, the same or similar features being referred to each other. The above description of the apparatus, the storage medium, and the computer program embodiments is similar to the description of the method embodiments for determining battery capacity described above, with similar advantageous effects as the method embodiments. For technical details not disclosed in the apparatus, the storage medium and the computer program embodiments of the present application, reference should be made to the description of the method embodiments of the present application.

The application embodiment provides a hardware entity of a computer device, as shown in fig. 6, where the hardware entity of the computer device 600 includes: the processor 601 generally controls the overall operation of the computer device 600. The communication interface 602 may enable a computer device to communicate with other terminals or servers over a network. The memory 603 is configured to store instructions and applications executable by the processor 601, and may also cache data (e.g., image data, audio data, voice communication data, and video communication data) to be processed or processed by various modules in the processor 601 and the computer device 600, which may be implemented by a FLASH memory (FLASH) or a random access memory (Random Access Memory, RAM). Data transfer may be performed between the processor 601, the communication interface 602, and the memory 603 via the bus 604.

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in various embodiments of the present application, the sequence number of each step/process described above does not mean that the execution sequence of each step/process should be determined by its functions and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present disclosure. The foregoing embodiment numbers of the present disclosure are merely for description and do not represent advantages or disadvantages of the embodiments.

It should be noted that, in the application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. The above described device embodiments are only illustrative, e.g. the division of the units is only one logical function division, and there may be other divisions in practice, such as: multiple units or components may be combined or may be integrated into another system, or some features may be omitted, or not performed. In addition, the various components shown or discussed may be coupled or directly coupled or communicatively coupled to each other via some interface, whether indirectly coupled or communicatively coupled to devices or units, whether electrically, mechanically, or otherwise.

The units described above as separate components may or may not be physically separate, and components shown as units may or may not be physical units; can be located in one place or distributed to a plurality of network units; some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment. In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may be separately used as one unit, or two or more units may be integrated in one unit; the integrated units may be implemented in hardware or in hardware plus software functional units.

The foregoing is merely an embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the technical scope of the present application should be included in the scope of the present application.

Claims

1. A method for determining a battery capacity, the method comprising:

Determining at least two standing opportunity points from charge and discharge moments corresponding to the historical charge and discharge data; the standing opportunity point represents historical charge-discharge data of the last charge-discharge moment determined when the discharge current in the historical charge-discharge data meets a first preset value and the discharge duration meets the first preset duration;

Determining a first accumulation sum of an accumulated ampere-hour integral capacity value of the battery cell at the target standing opportunity point and an accumulated ampere-hour integral capacity value in a previous and subsequent period of time and a second accumulation sum of a charge-discharge depth of the battery cell at the target standing opportunity point and a charge-discharge depth in the previous and subsequent period of time aiming at the target standing opportunity point;

And determining the ratio between the first accumulation sum of the electric core and the second accumulation sum of the corresponding electric core as the health state value of the electric core at the target standing opportunity point.

2. The method of claim 1, wherein screening the at least one target point of opportunity for resting based on the preset first screening condition comprises:

According to historical charge and discharge data between two standing opportunity points in the at least two standing opportunity points, determining the charge capacity and discharge capacity of each battery cell between the two standing opportunity points;

and reserving or deleting the two standing opportunity points based on the charge capacity and the discharge capacity of each cell.

3. The method of claim 2, wherein the reserving or deleting the two standing opportunity points based on the charge capacity and the discharge capacity of each cell comprises:

For each electric core, when the charging capacity of the electric core is larger than the battery capacity of a preset first target weight and the discharging capacity of the electric core is smaller than the battery capacity of a preset second target weight, reserving the two standing opportunity points, otherwise deleting the two standing opportunity points;

wherein the first target weight is related to a charge capacity error and a vehicle coverage rate, and the second target weight is related to a discharge capacity error and a vehicle coverage rate.

4. The method of claim 3, wherein the method of determining battery capacity further comprises:

Determining a first influence effect graph of different first weight coefficients on the charging capacity error and the vehicle coverage rate, wherein an abscissa is the first weight coefficient, and two ordinate are the charging capacity error and the vehicle coverage rate respectively;

Determining at least one charging capacity error under a preset first target vehicle coverage rate in the first influence effect graph; determining a first weight coefficient corresponding to the lowest charging capacity error among the at least one charging capacity error as a first target weight;

Or alternatively

Determining at least one vehicle coverage under a preset first target charging capacity error in the first influence effect graph; and determining a first weight coefficient corresponding to the vehicle coverage rate with the highest at least one vehicle coverage rate as a first target weight.

5. The method of claim 3, wherein the method of determining battery capacity further comprises:

Determining a second influence effect graph of different second weight coefficients on the discharge capacity error and the vehicle coverage rate, wherein an abscissa is the second weight coefficient, and two ordinate are the discharge capacity error and the vehicle coverage rate respectively;

Determining at least one discharge capacity error under a preset second target vehicle coverage rate in the second influence effect graph; determining a second weight coefficient corresponding to the lowest discharge capacity error in the at least one discharge capacity error as a second target weight;

Or alternatively

Determining at least one vehicle coverage under a preset discharge capacity error in the second influence effect graph; and determining a second weight coefficient corresponding to the highest vehicle coverage rate in the at least one vehicle coverage rate as a second target weight.

6. The method of any one of claims 1 to 5, wherein determining a depth of charge and discharge of a cell at the target point of opportunity for rest for the target point of opportunity comprises:

determining the starting time and the ending time of the historical discharge data corresponding to the target standing opportunity point;

For each electric core, based on the voltage of the electric core at the starting moment, inquiring a state of charge (SOC) -Open Circuit Voltage (OCV) mapping relation table, and determining the SOC value of the electric core at the starting moment;

for each battery cell, inquiring a state of charge (SOC) -Open Circuit Voltage (OCV) mapping relation table based on the voltage of the battery cell at the end time, and determining the SOC value of the battery cell at the end time;

And for each battery cell, determining the difference between the SOC value of the battery cell at the starting moment and the SOC value of the corresponding battery cell at the ending moment as the charge and discharge depth of the corresponding battery cell at the target standing opportunity point.

7. The method according to any one of claims 1 to 5, wherein determining at least two opportunity points for standing from charge-discharge moments corresponding to the historical charge-discharge data includes:

And determining at least two standing opportunity points from charging and discharging moments corresponding to the historical charging and discharging data based on a preset second screening condition, wherein the second screening condition is set for the discharging current of the battery cell and the continuous discharging duration under the discharging current.

8. A battery capacity determining apparatus, characterized in that the battery capacity determining apparatus includes:

The first determining module is used for determining at least two standing opportunity points from the charging and discharging moments corresponding to the historical charging and discharging data; the standing opportunity point represents historical charge-discharge data of the last charge-discharge moment determined when the discharge current in the historical charge-discharge data meets a first preset value and the discharge duration meets the first preset duration;

9. A computer device comprising a memory, a processor and a computer program stored on the memory, characterized in that the processor, when executing the computer program, realizes the steps in the method of determining the capacity of a battery according to any one of claims 1 to 7.

10. A computer readable storage medium having stored thereon a computer program or instructions, which when executed by a processor, realizes the steps in the method of determining battery capacity of any one of claims 1 to 7.