Methods, apparatus, equipment and media for determining the degradation state of battery packs

Abstract

This application provides a method, apparatus, device, and medium for determining the degradation state of a battery pack, relating to the field of battery pack technology. The method includes: acquiring the rated capacity of a reference battery pack and a first voltage of the reference battery pack during charge-discharge cycles under target operating conditions; wherein the historical charge-discharge count of the reference battery pack is less than a preset number; acquiring a second voltage and actual capacity of a battery pack under test during charge-discharge cycles under target operating conditions; wherein the reference battery pack and the battery pack under test are of the same model; determining the voltage plateau degradation rate of the battery pack under test based on the first and second voltages; determining the capacity degradation rate of the battery pack under test based on the rated capacity and actual capacity; and determining the degradation state of the battery pack under test based on the voltage plateau degradation rate and capacity degradation rate. The method, apparatus, device, and medium for determining the degradation state of a battery pack provided in this application can achieve high-precision assessment of the battery pack degradation state.

Description

Technical Field

[0001] This application relates to the field of battery pack technology, and in particular to a method, apparatus, device and medium for determining the degradation state of a battery pack. Background Technology

[0002] In actual use, battery packs inevitably age and degrade due to complex internal electrochemical reactions and varying external environmental and operating conditions. Accurately assessing the degradation state of battery packs is crucial for the Battery Management System (BMS) to achieve effective charge and discharge control, thermal management, and range prediction. At the same time, accurate estimation of battery pack degradation state is also a key basis for realizing the cascade utilization and recycling of battery packs, which helps to improve the economic value and resource utilization rate of batteries throughout their entire life cycle. Currently, the assessment technology for battery pack degradation state mainly faces the following challenges: (1) The aging mechanism of battery packs is complex and difficult to measure directly; (2) Existing assessment methods have limited accuracy and insufficient applicability.

[0003] Therefore, how to develop a method that can overcome the above difficulties and achieve high-precision battery pack degradation status assessment is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] This application provides a method, apparatus, device, and medium for determining the degradation state of a battery pack, thereby addressing the shortcomings of existing technologies in accurately assessing the degradation state of a battery pack and achieving high-precision battery pack degradation state assessment.

[0005] In a first aspect, this application provides a method for determining the degradation state of a battery pack, comprising: Obtain the rated capacity of the reference battery pack and the first voltage of the reference battery pack during charge-discharge cycles under target operating conditions; wherein the historical charge-discharge count of the reference battery pack is less than a preset number; The second voltage and actual capacity of the battery pack under test are obtained when it undergoes charge-discharge cycles under the target operating conditions; wherein the reference battery pack and the battery pack under test are of the same model. Based on the first voltage and the second voltage, determine the voltage plateau attenuation rate of the battery pack under test; Based on the rated capacity and the actual capacity, determine the capacity decay rate of the battery pack under test; The degradation state of the battery pack under test is determined based on the voltage plateau degradation rate and the capacity degradation rate.

[0006] Optionally, the target operating condition includes a target temperature; Determining the degradation state of the battery pack under test based on the voltage plateau degradation rate and the capacity degradation rate includes: From a plurality of preset temperature adjustment coefficients, a first temperature adjustment coefficient and a second temperature adjustment coefficient corresponding to the target temperature are determined; The degradation state of the battery pack under test is determined based on the voltage plateau attenuation rate, the capacity attenuation rate, the first temperature adjustment coefficient, and the second temperature adjustment coefficient.

[0007] Optionally, determining the degradation state of the battery pack under test based on the voltage plateau degradation rate, the capacity degradation rate, the first temperature adjustment coefficient, and the second temperature adjustment coefficient includes: The product of the voltage plateau attenuation rate and the first temperature adjustment coefficient is used as the first attenuation parameter; The product of the capacity decay rate and the second temperature adjustment coefficient is used as the second decay parameter; The sum of the first attenuation parameter and the second attenuation parameter is taken as the target sum; The difference between the preset first constant and the target sum is taken as the certified energy state of the battery pack under test; wherein the certified energy state is used to reflect the degradation state of the battery pack under test.

[0008] Optionally, determining the voltage plateau attenuation rate of the battery pack under test based on the first voltage and the second voltage includes: The difference between the first voltage and the second voltage is taken as the target difference; The quotient of the target difference divided by the first voltage is taken as the voltage plateau attenuation rate.

[0009] Optionally, determining the capacity degradation rate of the battery pack under test based on the rated capacity and the actual capacity includes: The quotient of the actual capacity divided by the rated capacity is taken as the target quotient; The difference between the preset second constant and the target quotient is taken as the capacity decay rate.

[0010] Optionally, obtaining the first voltage of the reference battery pack during charge-discharge cycles under target operating conditions includes: When the reference battery pack undergoes at least one charge-discharge cycle under the target operating condition, the first real-time charge-discharge voltage of the reference battery pack is collected at each charge-discharge cycle. The first voltage is determined based on the first real-time charge / discharge voltage during each charge / discharge cycle.

[0011] Optionally, determining the first voltage based on the first real-time charge / discharge voltage during each charge / discharge cycle includes: The first real-time charge / discharge voltage during each charge / discharge cycle is integrated over time to obtain the first integrated voltage for each charge / discharge cycle. The first average voltage of each charge-discharge cycle is obtained by dividing the first integral voltage at each charge-discharge cycle by the duration of each charge-discharge cycle. The average value of the first average voltage during each charge-discharge cycle is taken as the first voltage.

[0012] Optionally, obtaining the second voltage of the battery pack under test during charge-discharge cycles under the target operating conditions includes: When the battery pack under test undergoes at least one charge-discharge cycle under the target operating condition, the second real-time charge-discharge voltage of the battery pack under test is collected at each charge-discharge cycle. The second voltage is determined based on the second real-time charge / discharge voltage during each charge / discharge cycle.

[0013] Optionally, determining the second voltage based on the second real-time charge / discharge voltage during each charge / discharge cycle includes: The second real-time charge / discharge voltage at each charge / discharge cycle is integrated over time to obtain the second integrated voltage at each charge / discharge cycle; The second integrated voltage at each charge-discharge cycle is divided by the duration of each charge-discharge cycle to obtain the second average voltage at each charge-discharge cycle. The average value of the second average voltage during each charge-discharge cycle is taken as the second voltage.

[0014] Optionally, obtaining the actual capacity of the battery pack under test during charge-discharge cycles under the target operating conditions includes: When the battery pack under test undergoes at least one charge-discharge cycle under the target operating condition, the real-time charge-discharge current of the battery pack under test is collected during each charge-discharge cycle. The target capacity for each charge-discharge cycle is obtained by integrating the real-time charge-discharge current during each charge-discharge cycle over time. The average value of the target capacity during each charge-discharge cycle is taken as the actual capacity.

[0015] Optionally, the charging cutoff condition for the charge-discharge cycle includes the measured voltage of the battery pack reaching the upper limit voltage of the battery pack charging, and the discharging cutoff condition includes the measured voltage of the battery pack reaching the lower limit voltage of the battery pack discharging; a constant current mode is used during the charge-discharge cycle.

[0016] Optionally, the method for determining the battery pack degradation state further includes: If the degradation status of the battery pack under test is worse than a preset state, an early warning message is issued; wherein, the early warning message is used to prompt the user to inspect or replace the battery pack under test.

[0017] Secondly, this application also provides a device for determining the degradation state of a battery pack, comprising: The first acquisition module is used to acquire the rated capacity of the reference battery pack and the first voltage of the reference battery pack during charge-discharge cycles under target operating conditions; wherein the historical charge-discharge count of the reference battery pack is less than a preset count; The second acquisition module is used to acquire the second voltage and actual capacity of the battery pack under test during charge-discharge cycles under the target operating conditions; wherein the reference battery pack and the battery pack under test are of the same model. The first determining module is used to determine the voltage plateau attenuation rate of the battery pack under test based on the first voltage and the second voltage. The second determining module is used to determine the capacity decay rate of the battery pack under test based on the rated capacity and the actual capacity. The third determining module is used to determine the degradation state of the battery pack under test based on the voltage plateau degradation rate and the capacity degradation rate.

[0018] Optionally, the target operating condition includes a target temperature; The third determining module is used for: From a plurality of preset temperature adjustment coefficients, a first temperature adjustment coefficient and a second temperature adjustment coefficient corresponding to the target temperature are determined; The degradation state of the battery pack under test is determined based on the voltage plateau attenuation rate, the capacity attenuation rate, the first temperature adjustment coefficient, and the second temperature adjustment coefficient.

[0019] Optionally, the third determining module is used to: The product of the voltage plateau attenuation rate and the first temperature adjustment coefficient is used as the first attenuation parameter; The product of the capacity decay rate and the second temperature adjustment coefficient is used as the second decay parameter; The sum of the first attenuation parameter and the second attenuation parameter is taken as the target sum; The difference between the preset first constant and the target sum is taken as the certified energy state of the battery pack under test; wherein the certified energy state is used to reflect the degradation state of the battery pack under test.

[0020] Optionally, the first determining module is used to: The difference between the first voltage and the second voltage is taken as the target difference; The quotient of the target difference divided by the first voltage is taken as the voltage plateau attenuation rate.

[0021] Optionally, the second determining module is used to: The quotient of the actual capacity divided by the rated capacity is taken as the target quotient; The difference between the preset second constant and the target quotient is taken as the capacity decay rate.

[0022] Optionally, the first acquisition module is used for: When the reference battery pack undergoes at least one charge-discharge cycle under the target operating condition, the first real-time charge-discharge voltage of the reference battery pack is collected at each charge-discharge cycle. The first voltage is determined based on the first real-time charge / discharge voltage during each charge / discharge cycle.

[0023] Optionally, the first acquisition module is used for: The first real-time charge / discharge voltage during each charge / discharge cycle is integrated over time to obtain the first integrated voltage for each charge / discharge cycle. The first average voltage of each charge-discharge cycle is obtained by dividing the first integral voltage at each charge-discharge cycle by the duration of each charge-discharge cycle. The average value of the first average voltage during each charge-discharge cycle is taken as the first voltage.

[0024] Optionally, the second acquisition module is used for: When the battery pack under test undergoes at least one charge-discharge cycle under the target operating condition, the second real-time charge-discharge voltage of the battery pack under test is collected at each charge-discharge cycle. The second voltage is determined based on the second real-time charge / discharge voltage during each charge / discharge cycle.

[0025] Optionally, the second acquisition module is used for: The second real-time charge / discharge voltage at each charge / discharge cycle is integrated over time to obtain the second integrated voltage at each charge / discharge cycle; The second integrated voltage at each charge-discharge cycle is divided by the duration of each charge-discharge cycle to obtain the second average voltage at each charge-discharge cycle. The average value of the second average voltage during each charge-discharge cycle is taken as the second voltage.

[0026] Optionally, the second acquisition module is used for: When the battery pack under test undergoes at least one charge-discharge cycle under the target operating condition, the real-time charge-discharge current of the battery pack under test is collected during each charge-discharge cycle. The target capacity for each charge-discharge cycle is obtained by integrating the real-time charge-discharge current during each charge-discharge cycle over time. The average value of the target capacity during each charge-discharge cycle is taken as the actual capacity.

[0027] Optionally, the charging cutoff condition for the charge-discharge cycle includes the measured voltage of the battery pack reaching the upper limit voltage of the battery pack charging, and the discharging cutoff condition includes the measured voltage of the battery pack reaching the lower limit voltage of the battery pack discharging; a constant current mode is used during the charge-discharge cycle.

[0028] Optionally, the third determining module is further configured to: If the degradation status of the battery pack under test is worse than a preset state, an early warning message is issued; wherein, the early warning message is used to prompt the user to inspect or replace the battery pack under test.

[0029] Thirdly, this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method described in the first aspect.

[0030] Fourthly, this application also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in the first aspect.

[0031] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the method described in the first aspect.

[0032] The method, apparatus, equipment, and medium for determining the battery pack degradation state provided in this application determine the voltage plateau degradation rate by comparing a first voltage during charge-discharge cycles of a reference battery pack with a second voltage during charge-discharge cycles of the battery pack under test. Based on the rated capacity of the reference battery pack and the actual capacity of the battery pack under test during charge-discharge cycles, the capacity degradation rate is determined. The degradation state of the battery pack is then determined using both the voltage plateau degradation rate and the capacity degradation rate. Notably, the historical charge-discharge cycles of the reference battery are less than a preset number, meaning the reference battery can be a new battery. This allows for the prediction of the battery pack degradation state using a new battery pack as a reference, and enables the evaluation of the battery pack's degradation state from both voltage and capacity dimensions based on actual charge-discharge data, thus improving the accuracy of battery pack degradation state assessment. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a flowchart illustrating the method for determining the degradation state of a battery pack provided in an embodiment of this application. Figure 2 This is a schematic diagram of the structure of the battery pack degradation state determination device provided in the embodiments of this application; Figure 3 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions 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, 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.

[0036] This application provides a method for determining the degradation state of a battery pack. This method can be applied to a terminal or server for determining the degradation state of a battery pack. Taking the terminal for determining the degradation state of a battery pack as an example, it can be a control terminal that communicates with the battery management system via a network. The following description uses the control terminal as the subject of this method.

[0037] The aforementioned servers can be independent physical servers, server clusters or distributed systems composed of multiple physical servers, or cloud servers or server clusters providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDNs), and big data and artificial intelligence platforms. Terminals can be smartphones (such as Android phones, iOS phones, etc.), tablets, laptops, digital radio receivers, mobile internet devices (MIDs), handheld computers (PDAs), desktop computers, in-vehicle terminals (such as in-vehicle navigation terminals, in-vehicle computers, etc.), smart speakers, smartwatches, etc., without specific limitations. Terminals and battery management systems can be directly or indirectly connected to the network via wired or wireless communication, but are not limited to these methods. Specific details can also be determined based on the actual application scenario requirements, without further limitations.

[0038] The aforementioned networks may include, but are not limited to, wired networks and wireless networks. The wired networks include local area networks (LANs), metropolitan area networks (MANs), and wide area networks (WANs). The wireless networks include Bluetooth, Wi-Fi, and other networks that enable wireless communication.

[0039] Figure 1 This is a flowchart illustrating the method for determining the battery pack degradation state provided in an embodiment of this application. (Refer to...) Figure 1 The method may include: Step 110: Obtain the rated capacity of the reference battery pack and the first voltage of the reference battery pack during charge-discharge cycles under the target operating conditions; wherein, the historical charge-discharge count of the reference battery pack is less than the preset count; Step 120: Obtain the second voltage and actual capacity of the battery pack under test during charge-discharge cycles under target operating conditions; wherein, the reference battery pack and the battery pack under test are of the same model; Step 130: Determine the voltage plateau attenuation rate of the battery pack under test based on the first voltage and the second voltage; Step 140: Determine the capacity decay rate of the battery pack under test based on the rated capacity and the actual capacity; Step 150: Determine the degradation state of the battery pack under test based on the voltage plateau degradation rate and capacity degradation rate.

[0040] In step 110, the historical charge-discharge cycles of the reference battery pack are less than a preset number, which can be three. That is, a new battery pack can be selected as the reference battery pack. The control terminal can record the rated capacity of the reference battery pack and control it to perform charge-discharge cycles under target operating conditions to obtain the first voltage at that time. The target operating condition can be a standard charge-discharge condition.

[0041] In step 120, the control terminal can control the battery pack under test to undergo charge-discharge cycles under the same target operating conditions as the reference battery pack, and obtain the second voltage at this time, as well as the actual capacity of the battery pack under test through the real-time charge-discharge current during the charge-discharge cycle. The reference battery pack and the battery pack under test are of the same model, and the degradation state of the battery pack under test is accurately evaluated through the reference battery pack as a control variable.

[0042] In step 130, the control terminal can calculate the voltage plateau decay rate of the battery pack under test using the first voltage and the second voltage. The voltage plateau decay rate is an indicator of the stability of the voltage characteristics of the battery pack during charging and discharging. It describes the degree to which the relatively flat voltage range (i.e., the "voltage plateau") during constant current charging or discharging gradually shortens, decreases in voltage value, or increases in slope as the battery pack is used.

[0043] In step 140, the control terminal can determine the capacity degradation rate of the battery pack under test by comparing the rated capacity with the actual capacity. The capacity degradation rate is the most crucial and intuitive indicator for measuring the aging degree of the battery pack. It directly reflects the degree of degradation of the actual storable and releaseable electrical capacity relative to the initial nominal capacity after charge-discharge cycles or long-term storage.

[0044] In step 150, the control terminal can determine the state of certified energy (SOCE) of the battery pack under test by using the voltage plateau decay rate and the capacity decay rate. The SOCE reflects the degradation state of the battery pack under test.

[0045] The battery pack degradation state determination method provided in this application embodiment determines the voltage plateau degradation rate by comparing the first voltage of a reference battery pack during charge-discharge cycles with the second voltage of the battery pack under test during charge-discharge cycles. It then determines the capacity degradation rate based on the rated capacity of the reference battery pack and the actual capacity of the battery pack under test during charge-discharge cycles. Finally, it determines the battery pack degradation state by combining the voltage plateau degradation rate and the capacity degradation rate. The reference battery has fewer historical charge-discharge cycles than a preset number, meaning it can be a new battery. This method enables the prediction of battery pack degradation state using a new battery pack as a reference, and allows for the evaluation of battery pack degradation state from both voltage and capacity dimensions based on actual charge-discharge data, thus improving the accuracy of battery pack degradation state assessment.

[0046] In some embodiments, the target operating condition includes a target temperature; determining the degradation state of the battery pack under test based on the voltage plateau degradation rate and the capacity degradation rate includes: determining a first temperature adjustment coefficient and a second temperature adjustment coefficient corresponding to the target temperature from a plurality of preset temperature adjustment coefficients; and determining the degradation state of the battery pack under test based on the voltage plateau degradation rate, the capacity degradation rate, the first temperature adjustment coefficient, and the second temperature adjustment coefficient.

[0047] The target operating condition can include a target temperature T and a target charge / discharge rate. The target temperature is the ambient temperature, which can be measured by a temperature sensor. The target temperature generally needs to be greater than or equal to 0℃. When the target operating condition is a standard charge / discharge condition, the target temperature is 25℃±2℃, and the target charge / discharge rate is 0.3 times the rated capacity. When evaluating the degradation state of the battery pack under test, the influence of ambient temperature must also be considered. Therefore, the control terminal can determine the first temperature adjustment coefficient k1 and the second temperature adjustment coefficient k2 corresponding to the target temperature from multiple preset temperature adjustment coefficients, and then determine the degradation state of the battery pack under test based on three dimensions: voltage plateau degradation rate, capacity degradation rate, and the first and second temperature adjustment coefficients.

[0048] The correspondence between the target temperature T and the first temperature adjustment coefficient k1 and the second temperature adjustment coefficient k2 is shown in Table 1 below:

[0049] Table 1 Preset Temperature Adjustment Coefficient Table Table 1 was obtained from discharge test data under different ambient temperatures. Specifically, an ambient temperature of 25°C was used as a baseline, where both the first temperature adjustment coefficient k1 and the second temperature adjustment coefficient k2 were 1, and the first certified energy state (constant) was measured at this temperature. Then, multiple second certified energy states (including algebraic expressions of k1 and k2) were measured when the ambient temperature was not 25°C. By controlling the first and second certified energy states to be approximately equal, k1 and k2 were adjusted to obtain the above table. When the ambient temperature is not recorded in Table 1, the corresponding first and second temperature adjustment coefficients can be obtained through interpolation.

[0050] The method for determining the battery pack degradation state provided in this application embodiment determines the voltage plateau degradation rate by comparing the first voltage of a reference battery pack during charge-discharge cycles with the second voltage of the battery pack under test during charge-discharge cycles. It then determines the capacity degradation rate based on the rated capacity of the reference battery pack and the actual capacity of the battery pack under test during charge-discharge cycles. Finally, it determines a first temperature adjustment coefficient and a second temperature adjustment coefficient using the target temperature during charge-discharge cycles. The degradation state of the battery pack is then determined using the voltage plateau degradation rate, the capacity degradation rate, and the first and second temperature adjustment coefficients. The reference battery has fewer historical charge-discharge cycles than a preset number, meaning it can be a new battery. This method predicts the battery pack degradation state using a new battery pack as a reference. It not only assesses the battery pack degradation state from both voltage and capacity dimensions based on actual charge-discharge data, improving the accuracy of degradation state assessment, but also expands the assessment scenarios by introducing temperature adjustment coefficients to evaluate the battery pack degradation state under various temperature conditions.

[0051] In some embodiments, determining the degradation state of the battery pack under test based on the voltage plateau degradation rate, capacity degradation rate, first temperature adjustment coefficient, and second temperature adjustment coefficient includes: using the product of the voltage plateau degradation rate and the first temperature adjustment coefficient as a first degradation parameter; using the product of the capacity degradation rate and the second temperature adjustment coefficient as a second degradation parameter; using the sum of the first degradation parameter and the second degradation parameter as a target sum; and using the difference between a preset first constant and the target sum as the certified energy state of the battery pack under test; wherein the certified energy state is used to reflect the degradation state of the battery pack under test.

[0052] The certified state of energy of the battery pack under test can be calculated using the following formula: SOCE = 1 - (k1 × +k2× ) Where SOCE is the certified state of energy of the battery pack under test, 1 is a preset first constant, and k1 is the first temperature adjustment coefficient. k1 is the voltage plateau attenuation rate, and k2 is the second temperature regulation coefficient. It is the capacity decay rate.

[0053] As the battery pack is used, it will experience a certain degree of degradation. The certified energy status is the maximum usable energy of the battery pack in the current state divided by the factory-certified rated energy, which is a percentage. The certified energy status can more intuitively reflect the degradation status of the battery pack.

[0054] The battery pack degradation state determination method provided in this application embodiment determines the voltage plateau degradation rate by comparing the first voltage of a reference battery pack during charge-discharge cycles with the second voltage of the battery pack under test during charge-discharge cycles. It then determines the capacity degradation rate based on the rated capacity of the reference battery pack and the actual capacity of the battery pack under test during charge-discharge cycles. Finally, it determines a first temperature adjustment coefficient and a second temperature adjustment coefficient using the target temperature during charge-discharge cycles. Finally, it determines the battery pack degradation state using the voltage plateau degradation rate, capacity degradation rate, and the first and second temperature adjustment coefficients. This method achieves prediction of the battery pack degradation state with a reference battery pack. It not only assesses the battery pack degradation state from both voltage and capacity dimensions based on actual charge-discharge data, improving the accuracy of degradation state assessment, but also expands the assessment scenarios by introducing temperature adjustment coefficients to evaluate the battery pack degradation state under various temperature conditions.

[0055] In some embodiments, determining the voltage plateau attenuation rate of the battery pack under test based on the first voltage and the second voltage includes: taking the difference between the first voltage and the second voltage as a target difference; and taking the quotient of the target difference divided by the first voltage as the voltage plateau attenuation rate.

[0056] The voltage plateau decay rate is obtained by comparing the average voltage of the battery pack under test during charging and discharging with the reference voltage of a reference battery pack. The voltage plateau decay rate can be calculated using the following formula: =

[0057] in, It is the voltage plateau attenuation rate. It is the first voltage. It is the second voltage.

[0058] The voltage plateau attenuation rate ranges from 0 to 1, representing the degree of attenuation in the voltage plateau dimension.

[0059] The method for determining the degradation state of a battery pack provided in this application determines the voltage plateau degradation rate by comparing the first voltage of a reference battery pack during charge-discharge cycles with the second voltage of the battery pack under test during charge-discharge cycles. This method requires no complex electrochemical analysis or additional hardware deployment, has low computational complexity, and can be directly integrated into existing battery management systems, thus reducing implementation costs.

[0060] In some embodiments, determining the capacity decay rate of the battery pack under test based on the rated capacity and the actual capacity includes: using the quotient of the actual capacity divided by the rated capacity as the target quotient; and using the difference between a preset second constant and the target quotient as the capacity decay rate.

[0061] The capacity decay rate can be calculated using the following formula: =1-

[0062] in, It represents the capacity decay rate, and 1 is a preset second constant. This is the actual capacity. This is the rated capacity.

[0063] Capacity decay rate is a measure of the decline in State of Health (SOH). =1-SOH, where SOH= .

[0064] The method for determining the battery pack degradation state provided in this application determines the capacity degradation rate based on the rated capacity of a reference battery pack and the actual capacity of the battery pack under test during charge-discharge cycles. It has low computational complexity and is easy to implement.

[0065] In some embodiments, obtaining the first voltage of a reference battery pack during a charge-discharge cycle under target operating conditions includes: acquiring the first real-time charge-discharge voltage of the reference battery pack during each charge-discharge cycle when the reference battery pack undergoes at least one charge-discharge cycle under target operating conditions; and determining the first voltage based on the first real-time charge-discharge voltage during each charge-discharge cycle.

[0066] In some embodiments, determining a first voltage based on a first real-time charge / discharge voltage during each charge / discharge cycle includes: integrating the first real-time charge / discharge voltage during each charge / discharge cycle over time to obtain a first integrated voltage during each charge / discharge cycle; dividing the first integrated voltage during each charge / discharge cycle by the duration of each charge / discharge cycle to obtain a first average voltage during each charge / discharge cycle; and using the average value of the first average voltage during each charge / discharge cycle as the first voltage.

[0067] For example, when the reference battery pack completes three full charge-discharge cycles under standard charge-discharge conditions (target temperature 25℃±2℃, target charge-discharge rate 0.3 times rated capacity), the control terminal can use a voltage sensor to collect the real-time voltage of the first charge-discharge cycle of the reference battery pack during each charge-discharge cycle. Then, through the formula: =∫ (t)dt / First, the real-time voltage of the first charge / discharge cycle is determined. The first integral voltage is obtained by performing time integration, and then divided by the duration of each charge-discharge cycle. Obtain the first average voltage during each charge-discharge cycle. Then, the average value of the first average voltage during the three charge-discharge cycles is taken as the first voltage.

[0068] The method for determining the battery pack degradation state provided in this application calculates the first voltage by obtaining the first real-time charge-discharge voltage of the reference battery pack when it undergoes at least one charge-discharge cycle under the target operating conditions. This ensures the accuracy of the first voltage calculation, thereby enabling accurate calculation of the voltage plateau degradation rate and further improving the reliability of the battery pack degradation state assessment.

[0069] In some embodiments, obtaining the second voltage of the battery pack under test when it undergoes a charge-discharge cycle under target operating conditions includes: when the battery pack under test undergoes at least one charge-discharge cycle under target operating conditions, acquiring the second real-time charge-discharge voltage of the battery pack under test at each charge-discharge cycle; and determining the second voltage based on the second real-time charge-discharge voltage at each charge-discharge cycle.

[0070] In some embodiments, determining the second voltage based on the second real-time charge-discharge voltage during each charge-discharge cycle includes: integrating the second real-time charge-discharge voltage during each charge-discharge cycle over time to obtain the second integrated voltage during each charge-discharge cycle; dividing the second integrated voltage during each charge-discharge cycle by the duration of each charge-discharge cycle to obtain the second average voltage during each charge-discharge cycle; and using the average value of the second average voltage during each charge-discharge cycle as the second voltage.

[0071] For example, when the battery pack under test completes three full charge-discharge cycles under standard charge-discharge conditions (target temperature 25℃±2℃, target charge-discharge rate 0.3 times rated capacity), the control terminal can use a voltage sensor to collect the second real-time charge-discharge voltage of the battery pack under test during each charge-discharge cycle. Then, through the formula: =∫ (t)dt / First, the second charge / discharge real-time voltage during each charge / discharge cycle is... The second integral voltage is obtained by performing time integration, and then divided by the duration of each charge-discharge cycle. The second average voltage was obtained during each charge-discharge cycle. Then, the average value of the second average voltage during 3 charge-discharge cycles is taken as the second voltage.

[0072] The method for determining the battery pack degradation state provided in this application calculates the second voltage by obtaining the second real-time charge-discharge voltage of the battery pack under test when it undergoes at least one charge-discharge cycle under target operating conditions. This ensures the accuracy of the second voltage calculation and enables accurate calculation of the voltage plateau degradation rate, thereby further improving the reliability of the battery pack degradation state assessment.

[0073] In some embodiments, obtaining the actual capacity of the battery pack under test during charge-discharge cycles under target operating conditions includes: when the battery pack under test undergoes at least one charge-discharge cycle under target operating conditions, collecting the real-time charge-discharge current of the battery pack under test during each charge-discharge cycle; integrating the real-time charge-discharge current during each charge-discharge cycle over time to obtain the target capacity during each charge-discharge cycle; and taking the average value of the target capacity during each charge-discharge cycle as the actual capacity.

[0074] For example, when the battery pack under test completes 3 full charge-discharge cycles under standard charge-discharge conditions (target temperature of 25℃±2℃, target charge-discharge rate of 0.3 times rated capacity), the control terminal can collect the real-time charge-discharge current I of the battery pack under test during each charge-discharge cycle through the current sensor. Then, the target capacity C of each charge-discharge cycle is obtained by integrating the real-time charge-discharge current I during each charge-discharge cycle using the formula: C=∫I(t)dt. The average value of the target capacity C during the 3 charge-discharge cycles is then taken as the actual capacity.

[0075] The method for determining the battery pack degradation state provided in this application calculates the actual capacity by acquiring the real-time charge and discharge current of the battery pack under test during at least one charge and discharge cycle under target operating conditions. This ensures the accuracy of the actual capacity calculation and enables accurate calculation of the capacity degradation rate, thereby further improving the reliability of the battery pack degradation state assessment.

[0076] In some embodiments, the charging cutoff condition for the charge-discharge cycle includes the measured voltage of the battery pack reaching the upper limit voltage of the battery pack charging, and the discharging cutoff condition includes the measured voltage of the battery pack reaching the lower limit voltage of the battery pack discharging; a constant current mode is used during the charge-discharge cycle.

[0077] The charging and discharging cutoff conditions for the reference battery pack and the battery pack under test are as follows: the charging cutoff condition is when the measured voltage of the battery pack reaches the upper limit voltage of the battery pack charging, and the discharging cutoff condition is when the measured voltage of the battery pack reaches the lower limit voltage of the battery pack discharging. During the charging and discharging process, a constant current mode is used until the cutoff condition is reached, after which it switches to a constant voltage mode (charging stage) or stops discharging (discharging stage).

[0078] The method for determining the battery pack degradation state provided in this application embodiment, by limiting the use of constant current mode during charge-discharge cycles and the charge-discharge cutoff conditions of the charge-discharge cycles, can ensure the accurate acquisition of the first voltage, the second voltage, and the actual capacity of the battery pack under test, thereby enabling the calculation of accurate voltage plateau degradation rate and capacity degradation rate, and further improving the reliability of battery pack degradation state assessment.

[0079] In some embodiments, the method for determining the degradation state of a battery pack further includes: issuing a warning message if the degradation state of the battery pack under test is worse than a preset state; wherein the warning message is used to prompt the user to inspect or replace the battery pack under test.

[0080] The control terminal can monitor the degradation status of the battery pack in real time. If the degradation status of the battery pack under test is worse than the preset status, such as SOCE≤0.6, it indicates that the battery pack has malfunctioned or has been used for too long. At this time, the control terminal can issue an early warning message to prompt the user to inspect or replace the battery pack under test.

[0081] The method for determining the degradation state of a battery pack provided in this application provides a warning message when the degradation state of the battery pack under test is worse than a preset state, prompting the user to inspect or replace the battery pack under test. This can help avoid the risks caused by battery pack abnormalities and optimize the user experience.

[0082] Based on the descriptions of the above embodiments, the battery pack degradation state determination method provided in this application addresses the shortcomings of existing technologies that only focus on capacity degradation and ignore voltage plateau degradation, and whose voltage plateau degradation detection is complex. This method achieves a unified quantitative assessment of both battery pack capacity degradation and voltage plateau degradation, improving the comprehensiveness and accuracy of degradation assessment while reducing estimation costs and computational complexity. Compared with existing technologies, this application has the following beneficial effects: (1) Incorporating voltage plateau decay and capacity decay into a unified evaluation system makes up for the limitation of existing technologies that only evaluate capacity decay, and realizes a comprehensive quantitative evaluation of the overall decay status of the battery pack, providing a more accurate basis for battery maintenance strategy formulation; (2) The voltage plateau decay rate is calculated by simply comparing the average charge and discharge voltage of the battery pack under test with the reference voltage. No complex electrochemical analysis or additional hardware deployment is required. The calculation complexity is low and it can be directly integrated into the existing battery management system, which reduces the implementation cost. (3) The standard operating condition calibration reference parameters are adopted to ensure the comparability and accuracy of the estimation results. At the same time, it supports multi-operating condition adaptive calibration, which can be adapted to the battery degradation assessment needs under different usage scenarios. (4) The certified energy state value range is clear and the threshold determination is simple, which makes it easy for users to quickly judge the degree of battery pack degradation, trigger the warning mechanism, and improve the safety and reliability of battery use.

[0083] The following describes the apparatus for determining the battery pack degradation state provided in this application. The apparatus for determining the battery pack degradation state described below can be referred to in correspondence with the method for determining the battery pack degradation state described above.

[0084] Figure 2This is a schematic diagram of the structure of the battery pack degradation state determination device provided in an embodiment of this application. (Refer to...) Figure 2 The battery pack degradation state determination device provided in this application embodiment may include: The first acquisition module 210 is used to acquire the rated capacity of the reference battery pack and the first voltage of the reference battery pack when it is charged and discharged under the target operating conditions; wherein the historical charge and discharge count of the reference battery pack is less than a preset count; The second acquisition module 220 is used to acquire the second voltage and actual capacity of the battery pack under test when it undergoes charge-discharge cycles under the target operating conditions; wherein the reference battery pack and the battery pack under test are of the same model. The first determining module 230 is used to determine the voltage plateau attenuation rate of the battery pack under test based on the first voltage and the second voltage. The second determining module 240 is used to determine the capacity decay rate of the battery pack under test based on the rated capacity and the actual capacity. The third determining module 250 is used to determine the degradation state of the battery pack under test based on the voltage plateau degradation rate and the capacity degradation rate.

[0085] The battery pack degradation state determination device provided in this application determines the voltage plateau degradation rate by comparing the first voltage of a reference battery pack during charge-discharge cycles with the second voltage of the battery pack under test during charge-discharge cycles. It then determines the capacity degradation rate based on the rated capacity of the reference battery pack and the actual capacity of the battery pack under test during charge-discharge cycles. Finally, it determines the battery pack degradation state by combining the voltage plateau degradation rate and the capacity degradation rate. The reference battery has fewer historical charge-discharge cycles than a preset number, meaning it can be a new battery. This allows for the prediction of battery pack degradation state using a new battery pack as a reference. It can assess the battery pack degradation state from both voltage and capacity dimensions based on actual charge-discharge data, improving the accuracy of battery pack degradation state assessment.

[0086] In some embodiments, the target operating condition includes a target temperature; The third determining module is used for: From a plurality of preset temperature adjustment coefficients, a first temperature adjustment coefficient and a second temperature adjustment coefficient corresponding to the target temperature are determined; The degradation state of the battery pack under test is determined based on the voltage plateau attenuation rate, the capacity attenuation rate, the first temperature adjustment coefficient, and the second temperature adjustment coefficient.

[0087] In some embodiments, the third determining module is used to: The product of the voltage plateau attenuation rate and the first temperature adjustment coefficient is used as the first attenuation parameter; The product of the capacity decay rate and the second temperature adjustment coefficient is used as the second decay parameter; The sum of the first attenuation parameter and the second attenuation parameter is taken as the target sum; The difference between the preset first constant and the target sum is taken as the certified energy state of the battery pack under test; wherein the certified energy state is used to reflect the degradation state of the battery pack under test.

[0088] In some embodiments, the first determining module is configured to: The difference between the first voltage and the second voltage is taken as the target difference; The quotient of the target difference divided by the first voltage is taken as the voltage plateau attenuation rate.

[0089] In some embodiments, the second determining module is configured to: The quotient of the actual capacity divided by the rated capacity is taken as the target quotient; The difference between the preset second constant and the target quotient is taken as the capacity decay rate.

[0090] In some embodiments, the first acquisition module is used to: When the reference battery pack undergoes at least one charge-discharge cycle under the target operating condition, the first real-time charge-discharge voltage of the reference battery pack is collected at each charge-discharge cycle. The first voltage is determined based on the first real-time charge / discharge voltage during each charge / discharge cycle.

[0091] In some embodiments, the first acquisition module is used to: The first real-time charge / discharge voltage during each charge / discharge cycle is integrated over time to obtain the first integrated voltage for each charge / discharge cycle. The first average voltage of each charge-discharge cycle is obtained by dividing the first integral voltage at each charge-discharge cycle by the duration of each charge-discharge cycle. The average value of the first average voltage during each charge-discharge cycle is taken as the first voltage.

[0092] In some embodiments, the second acquisition module is used for: When the battery pack under test undergoes at least one charge-discharge cycle under the target operating condition, the second real-time charge-discharge voltage of the battery pack under test is collected at each charge-discharge cycle. The second voltage is determined based on the second real-time charge / discharge voltage during each charge / discharge cycle.

[0093] In some embodiments, the second acquisition module is used for: The second real-time charge / discharge voltage at each charge / discharge cycle is integrated over time to obtain the second integrated voltage at each charge / discharge cycle; The second integrated voltage at each charge-discharge cycle is divided by the duration of each charge-discharge cycle to obtain the second average voltage at each charge-discharge cycle. The average value of the second average voltage during each charge-discharge cycle is taken as the second voltage.

[0094] In some embodiments, the second acquisition module is used for: When the battery pack under test undergoes at least one charge-discharge cycle under the target operating condition, the real-time charge-discharge current of the battery pack under test is collected during each charge-discharge cycle. The target capacity for each charge-discharge cycle is obtained by integrating the real-time charge-discharge current during each charge-discharge cycle over time. The average value of the target capacity during each charge-discharge cycle is taken as the actual capacity.

[0095] In some embodiments, the charging cutoff condition for the charge-discharge cycle includes the measured voltage of the battery pack reaching the upper limit voltage of the battery pack charging, and the discharging cutoff condition includes the measured voltage of the battery pack reaching the lower limit voltage of the battery pack discharging; a constant current mode is used during the charge-discharge cycle.

[0096] In some embodiments, the third determining module is further configured to: If the degradation status of the battery pack under test is worse than a preset state, an early warning message is issued; wherein, the early warning message is used to prompt the user to inspect or replace the battery pack under test.

[0097] Specifically, the battery pack attenuation state determination device provided in this application embodiment can implement all the method steps implemented by the method embodiment with the execution subject being the control terminal, and can achieve the same technical effect. Here, the parts that are the same as those in the method embodiment and the beneficial effects will not be described in detail.

[0098] Figure 3 This is a schematic diagram of the structure of the electronic device provided in an embodiment of this application. For example... Figure 3 As shown, the electronic device may include: a processor 310, a communications interface 320, a memory 330, and a communication bus 340, wherein the processor 310, the communications interface 320, and the memory 330 communicate with each other via the communication bus 340. The processor 310 can call logical instructions in the memory 330 to execute a method for determining the battery pack's degradation state, such as including: Obtain the rated capacity of the reference battery pack and the first voltage of the reference battery pack during charge-discharge cycles under target operating conditions; wherein the historical charge-discharge count of the reference battery pack is less than a preset number; The second voltage and actual capacity of the battery pack under test are obtained when it undergoes charge-discharge cycles under the target operating conditions; wherein the reference battery pack and the battery pack under test are of the same model. Based on the first voltage and the second voltage, determine the voltage plateau attenuation rate of the battery pack under test; Based on the rated capacity and the actual capacity, determine the capacity decay rate of the battery pack under test; The degradation state of the battery pack under test is determined based on the voltage plateau degradation rate and the capacity degradation rate.

[0099] Furthermore, the logical instructions in the aforementioned memory 330 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0100] On the other hand, this application also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the method for determining the battery pack degradation state provided by the above methods, for example including: Obtain the rated capacity of the reference battery pack and the first voltage of the reference battery pack during charge-discharge cycles under target operating conditions; wherein the historical charge-discharge count of the reference battery pack is less than a preset number; The second voltage and actual capacity of the battery pack under test are obtained when it undergoes charge-discharge cycles under the target operating conditions; wherein the reference battery pack and the battery pack under test are of the same model. Based on the first voltage and the second voltage, determine the voltage plateau attenuation rate of the battery pack under test; Based on the rated capacity and the actual capacity, determine the capacity decay rate of the battery pack under test; The degradation state of the battery pack under test is determined based on the voltage plateau degradation rate and the capacity degradation rate.

[0101] Furthermore, this application also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to perform the steps of the battery pack degradation state determination method provided by the above methods, for example including: Obtain the rated capacity of the reference battery pack and the first voltage of the reference battery pack during charge-discharge cycles under target operating conditions; wherein the historical charge-discharge count of the reference battery pack is less than a preset number; The second voltage and actual capacity of the battery pack under test are obtained when it undergoes charge-discharge cycles under the target operating conditions; wherein the reference battery pack and the battery pack under test are of the same model. Based on the first voltage and the second voltage, determine the voltage plateau attenuation rate of the battery pack under test; Based on the rated capacity and the actual capacity, determine the capacity decay rate of the battery pack under test; The degradation state of the battery pack under test is determined based on the voltage plateau degradation rate and the capacity degradation rate.

[0102] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0103] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0104] It should also be noted that in the embodiments of this application, the terms "first," "second," etc., are used to distinguish similar objects, and not to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same class, and the number of objects is not limited. For example, the first object can be one or more.

[0105] In this application embodiment, the term "and / or" describes the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0106] In this application's embodiments, "determine B based on A" means that factor A must be considered when determining B. It is not limited to "B can be determined based solely on A," but should also include: "determine B based on A and C," "determine B based on A, C, and E," "determine C based on A, and further determine B based on C," etc. Additionally, it can include using A as a condition for determining B, for example, "when A meets the first condition, determine B using the first method"; another example, "when A meets the second condition, determine B," etc.; another example, "when A meets the third condition, determine B based on the first parameter," etc. Of course, it can also be a condition where A is a factor in determining B, for example, "when A meets the first condition, determine C using the first method, and further determine B based on C," etc.

[0107] In the embodiments of this application, the term "multiple" refers to two or more, and other quantifiers are similar.

[0108] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this application, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for determining the degradation state of a battery pack, characterized in that, include: Obtain the rated capacity of the reference battery pack and the first voltage of the reference battery pack during charge-discharge cycles under target operating conditions; wherein the historical charge-discharge count of the reference battery pack is less than a preset number; The second voltage and actual capacity of the battery pack under test are obtained when it undergoes charge-discharge cycles under the target operating conditions; wherein the reference battery pack and the battery pack under test are of the same model. Based on the first voltage and the second voltage, the voltage plateau attenuation rate of the battery pack under test is determined; Based on the rated capacity and the actual capacity, determine the capacity decay rate of the battery pack under test; The degradation state of the battery pack under test is determined based on the voltage plateau degradation rate and the capacity degradation rate.

2. The method for determining the battery pack degradation state according to claim 1, characterized in that, The target operating condition includes the target temperature; Determining the degradation state of the battery pack under test based on the voltage plateau degradation rate and the capacity degradation rate includes: From a plurality of preset temperature adjustment coefficients, a first temperature adjustment coefficient and a second temperature adjustment coefficient corresponding to the target temperature are determined; The degradation state of the battery pack under test is determined based on the voltage plateau attenuation rate, the capacity attenuation rate, the first temperature adjustment coefficient, and the second temperature adjustment coefficient.

3. The method for determining the battery pack degradation state according to claim 2, characterized in that, The determination of the degradation state of the battery pack under test based on the voltage plateau degradation rate, the capacity degradation rate, the first temperature adjustment coefficient, and the second temperature adjustment coefficient includes: The product of the voltage plateau attenuation rate and the first temperature adjustment coefficient is used as the first attenuation parameter; The product of the capacity decay rate and the second temperature adjustment coefficient is used as the second decay parameter; The sum of the first attenuation parameter and the second attenuation parameter is taken as the target sum; The difference between the preset first constant and the target sum is taken as the certified energy state of the battery pack under test; wherein the certified energy state is used to reflect the degradation state of the battery pack under test.

4. The method for determining the battery pack degradation state according to claim 1, characterized in that, The step of determining the voltage plateau attenuation rate of the battery pack under test based on the first voltage and the second voltage includes: The difference between the first voltage and the second voltage is taken as the target difference; The quotient of the target difference divided by the first voltage is taken as the voltage plateau attenuation rate.

5. The method for determining the battery pack degradation state according to claim 1, characterized in that, Determining the capacity decay rate of the battery pack under test based on the rated capacity and the actual capacity includes: The quotient of the actual capacity divided by the rated capacity is taken as the target quotient; The difference between the preset second constant and the target quotient is taken as the capacity decay rate.

6. The method for determining the battery pack degradation state according to claim 1, characterized in that, Obtaining the first voltage of the reference battery pack during charge-discharge cycles under target operating conditions includes: When the reference battery pack undergoes at least one charge-discharge cycle under the target operating condition, the first real-time charge-discharge voltage of the reference battery pack is collected at each charge-discharge cycle. The first voltage is determined based on the first real-time charge / discharge voltage during each charge / discharge cycle.

7. The method for determining the battery pack degradation state according to claim 6, characterized in that, Determining the first voltage based on the first real-time charge / discharge voltage during each charge / discharge cycle includes: The first real-time charge / discharge voltage during each charge / discharge cycle is integrated over time to obtain the first integrated voltage for each charge / discharge cycle. The first average voltage of each charge-discharge cycle is obtained by dividing the first integral voltage at each charge-discharge cycle by the duration of each charge-discharge cycle. The average value of the first average voltage during each charge-discharge cycle is taken as the first voltage.

8. The method for determining the battery pack degradation state according to claim 1, characterized in that, The step of obtaining the second voltage of the battery pack under test during charge-discharge cycles under the target operating conditions includes: When the battery pack under test undergoes at least one charge-discharge cycle under the target operating condition, the second real-time charge-discharge voltage of the battery pack under test is collected at each charge-discharge cycle. The second voltage is determined based on the second real-time charge / discharge voltage during each charge / discharge cycle.

9. The method for determining the battery pack degradation state according to claim 8, characterized in that, Determining the second voltage based on the second real-time charge / discharge voltage during each charge / discharge cycle includes: The second real-time charge / discharge voltage at each charge / discharge cycle is integrated over time to obtain the second integrated voltage at each charge / discharge cycle; The second integrated voltage at each charge-discharge cycle is divided by the duration of each charge-discharge cycle to obtain the second average voltage at each charge-discharge cycle. The average value of the second average voltage during each charge-discharge cycle is taken as the second voltage.

10. The method for determining the battery pack degradation state according to claim 1, characterized in that, Obtain the actual capacity of the battery pack under test during charge-discharge cycles under the target operating conditions, including: When the battery pack under test undergoes at least one charge-discharge cycle under the target operating condition, the real-time charge-discharge current of the battery pack under test is collected during each charge-discharge cycle. The target capacity for each charge-discharge cycle is obtained by integrating the real-time charge-discharge current during each charge-discharge cycle over time. The average value of the target capacity during each charge-discharge cycle is taken as the actual capacity.

11. The method for determining the battery pack degradation state according to claim 1, characterized in that, The charging cutoff condition for the charge-discharge cycle includes the measured voltage of the battery pack reaching the upper limit voltage of the battery pack charging, and the discharging cutoff condition includes the measured voltage of the battery pack reaching the lower limit voltage of the battery pack discharging; constant current mode is used during the charge-discharge cycle.

12. The method for determining the battery pack degradation state according to claim 1, characterized in that, Also includes: If the degradation status of the battery pack under test is worse than a preset state, an early warning message is issued; wherein, the early warning message is used to prompt the user to inspect or replace the battery pack under test.

13. A device for determining the degradation state of a battery pack, characterized in that, include: The first acquisition module is used to acquire the rated capacity of the reference battery pack and the first voltage of the reference battery pack during charge-discharge cycles under target operating conditions; wherein the historical charge-discharge count of the reference battery pack is less than a preset count; The second acquisition module is used to acquire the second voltage and actual capacity of the battery pack under test during charge-discharge cycles under the target operating conditions; wherein the reference battery pack and the battery pack under test are of the same model. The first determining module is used to determine the voltage plateau attenuation rate of the battery pack under test based on the first voltage and the second voltage. The second determining module is used to determine the capacity decay rate of the battery pack under test based on the rated capacity and the actual capacity. The third determining module is used to determine the degradation state of the battery pack under test based on the voltage plateau degradation rate and the capacity degradation rate.

14. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method for determining the battery pack degradation state as described in any one of claims 1 to 12.

15. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method for determining the battery pack degradation state as described in any one of claims 1 to 12.

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