Secondary battery capacity abnormality detection method, system, device, medium, and program product

Abstract

The invention relates to a secondary battery capacity anomaly detection method, a battery management system, electronic equipment, a computer readable storage medium and a computer program product, and belongs to the field of secondary batteries. The method for detecting the abnormal capacity of the secondary battery comprises the steps that in response to updating of the state of health (SOH) of the secondary battery, the capacity slope of the secondary battery is determined, and the capacity slope represents the change rate of the capacity of the secondary battery relative to the standard capacity of the secondary battery; determining whether the capacity of the secondary battery is abnormal or not according to the capacity slope and a preset capacity critical slope; wherein the preset capacity critical slope represents the capacity slope when the capacity of the secondary battery is abnormal. When judging whether the capacity of the secondary battery is abnormal or not, whether the capacity of the secondary battery is abnormal or not is judged by introducing the capacity slope (representing the change rate of the capacity of the secondary battery relative to the standard capacity of the secondary battery), so that whether the capacity of the secondary battery is abnormal or not can be detected earlier and more timely.

Description

Technical Field

[0001] This application belongs to the field of secondary batteries, specifically relating to a method for detecting abnormal capacity of a secondary battery, a battery management system, an electronic device, a computer-readable storage medium, and a computer program product. Background Technology

[0002] With the increasing power consumption of electronic devices and users' growing concern about battery life, the market demand for rechargeable batteries is growing. However, in practical applications, improper use can accelerate battery aging, leading to a significant drop in actual capacity compared to the original design capacity—a phenomenon known as "capacity drain." This capacity drain reduces battery life, requiring frequent charging and failing to meet long-term battery life needs. Users also cannot accurately assess remaining battery power, resulting in a poor user experience. More importantly, it increases safety risks. Capacity drain can be caused by battery damage, short circuits, insufficient electrolyte, or other issues. Therefore, timely identification of capacity drain or its trends is crucial for early warning of battery malfunctions and prompting users to take appropriate measures. Summary of the Invention

[0003] Therefore, the purpose of this application is to provide a method for detecting abnormal capacity of a secondary battery, a battery management system, an electronic device, a computer-readable storage medium, and a computer program product, so as to detect in a timely manner whether the capacity of a secondary battery is abnormal.

[0004] The embodiments of this application are implemented as follows:

[0005] In a first aspect, embodiments of this application provide a method for detecting abnormal capacity of a secondary battery, comprising: in response to updating the health status of the secondary battery, determining the capacity slope of the secondary battery, wherein the capacity slope characterizes the rate of change of the secondary battery capacity relative to the capacity of a reference secondary battery; determining whether the capacity of the secondary battery is abnormal based on the capacity slope and a preset capacity critical slope; wherein the preset capacity critical slope characterizes the capacity slope when the secondary battery capacity is abnormal.

[0006] In the above embodiments, when determining whether the secondary battery capacity is abnormal, it is no longer considered abnormal when the secondary battery capacity decays to a certain value. Instead, a capacity slope (determined based on the historical capacity data of the secondary battery, representing the rate of change of the secondary battery capacity relative to the baseline secondary battery capacity) is introduced to determine whether the secondary battery capacity is abnormal. This allows for earlier and more timely detection of whether the secondary battery capacity is abnormal.

[0007] In one possible implementation of the first aspect embodiment, in response to updating the health status of the secondary battery, determining the capacity slope of the secondary battery includes: in response to updating the health status of the secondary battery, obtaining the total number of charging or discharging cycles of the current secondary battery, wherein if the proportion of the secondary battery capacity in a single charging or discharging cycle to the total capacity is greater than or equal to a first preset value, then updating the total number of cycles; and in response to the total number of cycles being greater than or equal to the preset number of cycles, determining the capacity slope of the secondary battery.

[0008] In the above embodiments, in response to updating the health status of the secondary battery, the total number of charging or discharging cycles of the current secondary battery is obtained. Only when the total number of cycles is greater than or equal to the preset number of cycles (e.g., the secondary battery capacity does not decrease within the preset number of cycles, or the secondary battery capacity decreases within the allowable error range), the capacity slope of the secondary battery is determined. This can save the detection time for capacity abnormalities in the early stage of secondary battery use.

[0009] In one possible implementation of the first aspect embodiment, in response to updating the health status of the secondary battery, determining the capacity slope of the secondary battery includes: if the total number of charging or discharging cycles of the secondary battery is greater than or equal to a preset number of cycles, in response to each update of the health status of the secondary battery, determining the capacity slope of the secondary battery.

[0010] In the above embodiments, when the total number of charging or discharging cycles of the secondary battery is greater than or equal to the preset number of cycles, the capacity slope of the secondary battery is determined in response to each update of the secondary battery's health status, which is beneficial for timely detection of whether the secondary battery capacity is abnormal.

[0011] In one possible implementation of the first aspect embodiment, determining the capacity slope of the secondary battery includes: obtaining the total number of charging or discharging cycles and the current secondary battery capacity; obtaining a reference secondary battery capacity for a specified number of cycles within a preset reference cycle number interval, wherein the secondary battery capacity within the preset reference cycle number interval has no capacity decay, or the secondary battery capacity decay is less than a second preset value; and determining the capacity slope of the secondary battery based on the total number of cycles, the current secondary battery capacity, the specified cycle number, and the reference secondary battery capacity.

[0012] In the above embodiments, a reference secondary battery capacity with a specified number of cycles within a preset reference cycle number range is selected as the reference, and the capacity slope is calculated based on this. This can truly reflect the rate of change of the secondary battery capacity relative to the reference secondary battery capacity, thereby improving the accuracy of the judgment.

[0013] In one possible implementation of the first aspect embodiment, obtaining the reference secondary battery capacity for a specified number of cycles within a preset reference cycle number interval includes: obtaining the reference secondary battery capacity for each of a plurality of specified cycle numbers within the preset reference cycle number interval; wherein the cycle number interval between the plurality of specified cycle numbers is not less than a third preset value; correspondingly, determining the capacity slope of the secondary battery based on the total cycle number, the current secondary battery capacity, the specified cycle number, and the reference secondary battery capacity includes: obtaining a plurality of capacity slopes of the secondary battery based on the total cycle number, the current secondary battery capacity, each specified cycle number and its corresponding reference secondary battery capacity; wherein one specified cycle number corresponds to one capacity slope; and determining the capacity slope of the secondary battery based on the plurality of capacity slopes.

[0014] In the above embodiments, by obtaining the reference secondary battery capacity of each of the multiple specified cycle numbers located within the preset reference cycle number range, multiple capacity slopes are calculated, and the final capacity slope (such as the average of multiple capacity slopes) is determined based on the multiple capacity slopes to improve accuracy.

[0015] In one possible implementation of the first aspect embodiment, determining whether the secondary battery capacity is abnormal based on the capacity slope and the preset capacity critical slope includes: determining that the secondary battery capacity is abnormal if the difference between the capacity slope and the preset capacity critical slope is greater than a preset range; or determining that the secondary battery capacity is abnormal if the difference between the capacity slope determined multiple times consecutively and the preset capacity critical slope is greater than a preset range.

[0016] In the above embodiments, on the one hand, the fault tolerance rate is enhanced by setting a preset range. On the other hand, the secondary battery capacity is determined to be abnormal only when the difference between the capacity slope determined in multiple consecutive calculations and the preset capacity critical slope is greater than the preset range. This reduces the impact of single calculation errors and thus improves accuracy.

[0017] In one possible implementation of the first aspect embodiment, the method further includes: in response to a secondary battery capacity abnormality, indicating a secondary battery capacity abnormality and activating limiting measures; wherein the limiting measures include at least one of limiting the charging capacity of the secondary battery, limiting the number of times the secondary battery is charged, and limiting the maximum allowable current during secondary battery charging.

[0018] In the above embodiments, when the secondary battery capacity is abnormal, in addition to indicating that the secondary battery capacity is abnormal, restrictive measures are also activated to enhance the safety of the secondary battery.

[0019] In one possible implementation of the first aspect embodiment, the method further includes: in response to each update of the secondary battery's health status, acquiring and storing the number of charging or discharging cycles of the secondary battery and the secondary battery capacity.

[0020] In the above embodiments, in response to each update of the secondary battery's health status, the number of charging or discharging cycles and the secondary battery capacity are acquired and saved, so that when calculating the capacity slope of the secondary battery, it can be determined based on the previously saved number of cycles and the secondary battery capacity.

[0021] Secondly, embodiments of this application also provide a battery management system, including: an information acquisition module and a processing module; the information acquisition module is used to determine the capacity slope of the secondary battery in response to updating the health status of the secondary battery, wherein the capacity slope characterizes the rate of change of the secondary battery capacity relative to the capacity of a reference secondary battery; the processing module is used to determine whether the capacity of the secondary battery is abnormal based on the capacity slope and a preset capacity critical slope; wherein the preset capacity critical slope characterizes the capacity slope when the secondary battery capacity is abnormal.

[0022] Thirdly, embodiments of this application also provide an electronic device, including: a memory and a processor, the processor being connected to the memory; the memory being used to store a program; the processor being used to invoke the program stored in the memory to execute the method provided by any possible implementation of the first aspect embodiment and / or in combination with the first aspect embodiment.

[0023] Fourthly, embodiments of this application also provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, performs the method provided by any possible implementation of the first aspect embodiments and / or in combination with the first aspect embodiments.

[0024] Fifthly, embodiments of this application also provide a computer program product, the computer program product including a computer program, which, when run by a processor, performs the method provided by any possible implementation of the first aspect embodiment and / or in combination with the first aspect embodiment.

[0025] The effective effects of the second to fifth aspects of the above embodiments are the same as those of the aforementioned method embodiments, and will not be repeated here for the sake of brevity.

[0026] Other features and advantages of this application will be set forth in the following description. The objectives and other advantages of this application can be realized and obtained through the structures specifically pointed out in the written description and the accompanying drawings. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The above and other objects, features, and advantages of this application will become clearer through the drawings. The same reference numerals indicate the same parts in all the drawings. The drawings are not intentionally drawn to scale to actual size; the focus is on illustrating the main points of this application.

[0028] Figure 1 The diagram shows a flowchart of a method for detecting abnormal capacity of a secondary battery according to an embodiment of this application.

[0029] Figure 2 The diagram illustrates the principle of a secondary battery capacity anomaly detection method provided in an embodiment of this application.

[0030] Figure 3 This diagram illustrates the relationship between SOH and cycle number of a secondary battery according to an embodiment of this application.

[0031] Figure 4 This diagram illustrates the relationship between the capacity slope and the number of cycles of another secondary battery provided in this application embodiment.

[0032] Figure 5 This diagram illustrates the relationship between SOH and cycle number for another type of secondary battery provided in this application.

[0033] Figure 6 This diagram illustrates the relationship between the capacity slope and the number of cycles of a secondary battery according to an embodiment of this application.

[0034] Figure 7 A schematic diagram of a battery management system provided in an embodiment of this application is shown.

[0035] Figure 8 A schematic diagram of the structure of an electronic device provided in an embodiment of this application is shown. Detailed Implementation

[0036] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0037] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, relational terms such as "first," "second," etc., in the description of this application are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0038] Furthermore, the term "and / or" in this application is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0039] To promptly detect abnormalities and declining capacity trends in secondary batteries, this application provides a novel method for detecting abnormal secondary battery capacity, departing from existing methods in related technologies. These methods typically rely on the battery's State of Health (SOH). For example, the secondary battery capacity is calculated as: maximum capacity (nominal capacity) * SOH. When the capacity decays to a certain value, the battery's lifespan is considered over, prompting the user to replace it. Here, SOH represents a percentage of the battery's current health condition relative to its original, healthy state.

[0040] Since electronic devices (such as mobile phones, tablets, laptops, drones, etc.) rarely operate under full charge and discharge conditions, the state of harmonics (SOH) of a secondary battery is not obtained with every charge or discharge cycle, meaning the current capacity of the secondary battery is not guaranteed with each charge or discharge cycle. Given that the SOH update of a secondary battery is discontinuous in real-world electronic device applications, and considering that secondary batteries experiencing a significant capacity drop often exhibit substantial capacity decay within a small number (e.g., 10) of charge or discharge cycles, failure to detect abnormal battery capacity in a timely manner can easily lead to safety malfunctions.

[0041] The secondary battery in this application is in contrast to the primary battery (such as a dry cell battery or an alkaline battery). The secondary battery can also be called a rechargeable battery, which is a battery that can restore electrical energy through the charging process. Unlike the primary battery, the secondary battery can be recharged by an external power source after being discharged, and thus reused.

[0042] Based on this, this application provides a method for quickly detecting whether the capacity of a secondary battery is abnormal based on historical capacity data. Instead of considering a secondary battery abnormal simply because its capacity has decayed to a certain value, this method introduces a capacity slope (which can be determined based on historical capacity data) to determine whether the secondary battery capacity is abnormal. The following is a combination of... Figure 1 This application provides an example of a method for detecting abnormal capacity in secondary batteries.

[0043] S1: In response to updating the health status of the secondary battery, determine the capacity slope of the secondary battery.

[0044] In response to updating the State of Health (SOH) of the secondary battery, the capacity slope of the secondary battery is determined. In one possible implementation, the Battery Management System (BMS) determines the capacity slope of the secondary battery each time the SOH of the secondary battery is updated.

[0045] Given that the capacity of a secondary battery rarely decreases or remains within acceptable limits during the early stages of use, to save time on capacity detection during this period, in some possible implementations, S1 can be implemented as follows: if the total number of charging or discharging cycles of the secondary battery is greater than or equal to a preset number of cycles (configurable, such as 150 cycles), the capacity slope of the secondary battery is determined each time the State of Health (SOH) of the secondary battery is updated. In this implementation, the battery management system only determines the capacity slope of the secondary battery each time the SOH of the secondary battery is updated after the total number of charging or discharging cycles is greater than or equal to the preset number of cycles. If the total number of charging or discharging cycles of the secondary battery is less than the preset number of cycles, the battery management system may not determine the capacity slope of the secondary battery each time the SOH of the secondary battery is updated.

[0046] The preset cycle count can be used to characterize the frequency of charging or discharging of the secondary battery. When the usage frequency of the secondary battery is less than a certain value, it can be considered that its capacity decays very little, or that the capacity decay is within an acceptable range. For example, when the preset cycle count is less than 150, it can be considered that its capacity decays very little, or that the capacity decay is within an acceptable range.

[0047] In some possible implementations, the above-described S1 process can also be as follows: in response to updating the State of Health (SOH) of the secondary battery, the total number of charging or discharging cycles of the secondary battery is obtained; in response to the total number of cycles being greater than or equal to a preset number of cycles, the capacity slope of the secondary battery is determined, wherein the proportion of the secondary battery capacity in a single charge or discharge cycle to the total capacity is greater than or equal to a first preset value, and then the total number of cycles is updated. In this implementation, the battery management system may obtain the total number of charging or discharging cycles of the secondary battery each time the SOH of the secondary battery is updated, and only determine the capacity slope of the secondary battery when the total number of cycles is greater than or equal to the preset number of cycles.

[0048] The State of Health (SOH) update of a secondary battery depends on the SOH update strategy. It can be that the battery management system monitors parameters such as voltage, current, and temperature of the secondary battery during charging or discharging and updates the SOH based on these parameters; or, when the secondary battery is idle, the battery management system will update the SOH periodically even if the secondary battery is not charging or discharging; or, the SOH can be updated according to a fixed update cycle.

[0049] The total cycle count in this application refers to the current number of charge or discharge cycles of the secondary battery. As the number of charge or discharge cycles of the secondary battery increases, the total cycle count will increase. Given that the secondary batteries of electronic devices are often not fully charged or fully discharged during use, for example, the secondary battery may start charging from 20% SOC (State of Charge, which represents the ratio of the current remaining capacity of the secondary battery to the maximum capacity (i.e., total capacity) of a fully charged state, and then the cycle count for this charge or discharge cycle is recorded as 0.8; or, for example, the secondary battery may start charging from 10% SOC and then charge to 90% SOC, and then the cycle count for this charge or discharge cycle is recorded as 0.8; or, if a cycle is discharged from 100% SOC to 20% SOC, then the cycle count for this charge or discharge cycle is recorded as 0.8. Assuming that the cumulative number of charge or discharge cycles of the secondary battery before this cycle count is 200, then the updated cycle count is 200.8.

[0050] In some possible implementations, besides determining the cycle count based on the actual SOC of charging or discharging as described above, another approach is to count a cycle as follows: when the ratio of the capacity of a single discharge to the total capacity is greater than a first preset threshold (configurable), such as 80%, it is counted as one cycle. For example, discharging a secondary battery from 90% SOC to 5% SOC counts as one cycle, and the cycle count is incremented by 1. If the ratio of the capacity of a single discharge to the total capacity is less than 20%, the cycle is not counted. Similarly, when the ratio of the capacity of a single charge to the total capacity is greater than the first preset threshold, such as 80%, it is counted as one cycle. For example, charging from 5% SOC to 85% SOC counts as one cycle, and the cycle count is incremented by 1. If the ratio of the capacity of a single charge to the total capacity is less than 20%, the cycle is not counted. In this implementation, the total cycle count is only updated when the ratio of the secondary battery capacity during a single charge or discharge to the total capacity is greater than or equal to the first preset value. Here, SOC represents the ratio of the current remaining capacity of the secondary battery to its maximum capacity in a fully charged state.

[0051] Total capacity refers to the maximum capacity that a secondary battery can store. When the capacity of a secondary battery does not decrease, the total capacity can be the nominal capacity. As charge and discharge cycles proceed, the total capacity of a secondary battery will gradually decrease, which is usually referred to as battery aging or capacity decay.

[0052] The capacity slope characterizes the rate of change of the secondary battery capacity relative to the reference secondary battery capacity. It can be determined based on the total number of charging or discharging cycles of the current secondary battery, the current secondary battery capacity, and the reference secondary battery capacity at a specified number of cycles. In this implementation, the process of determining the capacity slope of the secondary battery can be as follows: obtain the total number of charging or discharging cycles and the current secondary battery capacity; obtain the reference secondary battery capacity at a specified number of cycles within a preset reference cycle number interval; and determine the capacity slope of the secondary battery based on the total number of cycles, the current secondary battery capacity, the specified number of cycles, and the reference secondary battery capacity. The preset reference cycle number interval is a pre-set or pre-defined interval serving as a reference, within which the secondary battery capacity does not decrease, or the secondary battery capacity decreases by less than a second preset value (configurable, such as a decrease rate of less than 5%).

[0053] The reference secondary battery capacity refers to the secondary battery capacity when the number of charging or discharging cycles is within a preset reference cycle range. If the secondary battery capacity does not decrease within the preset reference cycle range, the reference secondary battery capacity can be the nominal capacity.

[0054] When obtaining the total number of charging or discharging cycles of the current secondary battery, the total number of charging or discharging cycles can be obtained based on the above-mentioned total cycle counting rules. The total cycle count is updated every time the secondary battery is charged or discharged.

[0055] When obtaining the capacity of a secondary battery, it can be determined by obtaining the current state of equilibrium (SOH) of the secondary battery. For example, the secondary battery capacity = maximum secondary battery capacity (nominal capacity) * SOH.

[0056] In one possible implementation, the process of determining the capacity slope of the secondary battery based on the total number of cycles, the current secondary battery capacity, the specified number of cycles, and the reference secondary battery capacity can be: Capacity slope = (Reference secondary battery capacity - Current secondary battery capacity) / (Total number of cycles - Specified number of cycles). As the secondary battery is used, its capacity will gradually decrease, while the total number of charging or discharging cycles will increase. That is, the current secondary battery capacity will be less than the reference secondary battery capacity, while the total number of cycles will be greater than the specified number of cycles.

[0057] Within a preset baseline cycle number range, the secondary battery capacity exhibits no degradation, or the degradation is less than a second preset value. For example, the baseline cycle number range could be the interval [0, 200]. The specified cycle number can be any specified cycle number within this interval; for example, the specified cycle number could be 100 cycles. In some possible implementations, it may be impossible to obtain the capacitance of the secondary battery at exactly 100 cycles of charging or discharging. In such cases, the secondary battery capacity near 100 cycles can be selected. For example, assuming the secondary battery capacities at 97.5 cycles and 105 cycles are recorded, since 97.5 cycles is closer to 100 cycles, when it is impossible to obtain the capacitance of the secondary battery at exactly 100 cycles of charging or discharging, the capacitance at 97.5 cycles can be used as the capacitance at 100 cycles.

[0058] Among them, the baseline secondary battery capacity of a specified number of cycles within the preset baseline cycle number range is historical data. During the use of the secondary battery, the cycle number can be counted according to the above cycle number counting rules. For example, when the counted cycle number is within the preset baseline cycle number range, the corresponding baseline secondary battery capacity is obtained and saved each time the cycle number is updated. In this way, the baseline secondary battery capacity of a specified number of cycles within the preset baseline cycle number range can be obtained.

[0059] In some possible implementations, the current cycle number and the corresponding secondary battery capacity can be recorded each time the State of Health (SOH) is updated. Alternatively, a baseline secondary battery capacity of a specified cycle number within a preset baseline cycle number range can be obtained. In this implementation, the above-described secondary battery capacity anomaly detection method further includes: in response to each update of the secondary battery's SOH, acquiring and saving the secondary battery charging or discharging cycle number and the secondary battery capacity.

[0060] In one possible implementation, when obtaining the reference secondary battery capacity for a specified number of cycles within a preset reference cycle number range, it may be possible to obtain only the reference secondary battery capacity for a specified number of cycles within the preset reference cycle number range.

[0061] In some other possible implementations, obtaining the reference secondary battery capacity for a specified number of cycles within a preset reference cycle number range can be achieved by obtaining the reference secondary battery capacity for each of multiple specified cycle numbers within the preset reference cycle number range; wherein the cycle number interval between the multiple specified cycle numbers is not less than a third preset value (configurable, such as 10 cycles). In this implementation, the process of determining the capacity slope of the secondary battery based on the total number of cycles, the current secondary battery capacity, the specified cycle number, and the reference secondary battery capacity can be as follows: multiple capacity slopes of the secondary battery are obtained based on the total number of cycles, the current secondary battery capacity, each specified cycle number, and its corresponding reference secondary battery capacity; and the capacity slope of the secondary battery is determined based on these multiple capacity slopes. Each specified cycle number corresponds to one capacity slope. In this implementation, multiple capacity slopes are obtained, and then the capacity slope of the secondary battery is determined based on these multiple capacity slopes; for example, the capacity slope of the secondary battery is the average of the multiple capacity slopes.

[0062] For example, obtain the baseline secondary battery capacity for 50 cycles (or nearby), 100 cycles (or nearby), and 150 cycles (or nearby) within a preset baseline cycle number range. This allows you to calculate three capacity slopes. Then, based on these three capacity slopes, determine the final capacity slope. Each capacity slope can be calculated as follows: Capacity slope = (Baseline secondary battery capacity - Current secondary battery capacity) / (Total number of cycles - Specified number of cycles).

[0063] S2: Determine whether the capacity of the secondary battery is abnormal based on the capacity slope and the preset capacity critical slope.

[0064] After determining the capacity slope of the secondary battery (which can be represented by k), it is possible to determine whether the capacity of the secondary battery is abnormal based on the capacity slope and the preset capacity critical slope (which can be represented by k0).

[0065] The preset capacity critical slope represents the capacity slope when the secondary battery capacity is abnormal. The preset capacity critical slope can be set according to the secondary battery's product manual or based on historical experience. For example, when setting it according to the product manual, assuming the secondary battery capacity is 2600mAh and the manual specifies that the secondary battery should retain more than 80% of its capacity after 800 cycles, then the preset capacity critical slope k0 = 2600*(1-80%) / 800 = 0.65.

[0066] In some possible implementations, the process of determining whether the secondary battery capacity is abnormal based on the capacity slope and a preset critical capacity slope can be as follows: if the capacity slope is greater than the preset critical capacity slope, the secondary battery capacity is determined to be abnormal. In some possible implementations, if the difference between the capacity slope and the preset critical capacity slope is greater than a preset range (e.g., ±0.05), the secondary battery capacity is determined to be abnormal. To improve accuracy, the aforementioned capacity slope can be the average of multiple capacity slopes. Alternatively, when determining whether the secondary battery capacity is abnormal, the difference between the capacity slope determined multiple times consecutively and the preset critical capacity slope can all be greater than a preset range to determine that the secondary battery capacity is abnormal. This reduces the impact of single calculation errors, thereby improving accuracy.

[0067] In one possible implementation, the above-described secondary battery capacity anomaly detection method further includes: responding to a secondary battery capacity anomaly by indicating an anomaly and activating limiting measures; wherein the limiting measures include at least one of limiting the charging capacity of the secondary battery, limiting the number of charging cycles of the secondary battery, and limiting the maximum allowable current during charging of the secondary battery. In this implementation, when the secondary battery capacity is abnormal, in addition to indicating an anomaly, limiting measures are also activated to improve the safety of secondary battery use. For example, when limiting the charging capacity of the secondary battery, its maximum capacity should be lower than the current remaining capacity of the secondary battery (assuming 80%), so the maximum capacity should be lower than 80%. When limiting the number of charging cycles of the secondary battery, a maximum number of times the secondary battery can be charged can be set; exceeding this maximum number of times, the secondary battery will not be able to be charged, or charging will only be able to reach a set SOC. When limiting the maximum allowable current during charging of the secondary battery, a maximum allowable current during charging of the secondary battery can be set, for example, limiting the maximum current to 1A (amperes).

[0068] In one possible implementation, the schematic diagram of the above-described secondary battery capacity anomaly detection method can be as follows: Figure 2 As shown. Figure 2 The schematic diagram shown is only one of many embodiments of the above example.

[0069] To verify the secondary battery capacity anomaly detection method shown in this application, a certain secondary battery was selected for cycle aging test to verify the method. Some of the secondary batteries were artificially modified to create defects that would worsen their cycle performance. During the test phase, the secondary battery was judged in real time based on the test data to determine whether a capacity anomaly had occurred. The verification process is as follows.

[0070] Example 1:

[0071] Assuming the secondary battery has a capacity of 2600mAh, and the product specification states that it retains more than 80% of its capacity after 800 cycles, then k0 = 2600 * (1 - 80%) / 800 = 0.65. This experiment was conducted under laboratory conditions, testing four secondary batteries (denoted as #1, #2, #3, and #4). Batteries #3 and #4 were intentionally modified (e.g., overcharging or discharging, or use in extreme environments (high or low temperatures)) to degrade their cycle performance. Each charge-discharge cycle was a complete charge-discharge cycle, allowing for the timely calculation of the State of Harmony (SOH). The relationship between the calculated SOH and the cycle number for each secondary battery is as follows: Figure 3 As shown. After the secondary battery cycle count exceeds 150 cycles, the capacity slope k of the secondary battery is calculated in real time. The secondary battery slope k is as follows: Figure 4 As shown in the figure. Based on the slope, it can be seen that k of the secondary batteries #3 and #4 has exceeded the critical capacity slope k0, at which point it can be considered that the capacity of the secondary batteries is abnormal.

[0072] Example 2:

[0073] Assuming the secondary battery has a capacity of 2600mAh, and the product specification states that it retains more than 80% of its capacity after 800 cycles, then k0 = 2600 * (1 - 80%) / 800 = 0.65. This experiment simulates the application scenarios of electronic devices. Two secondary batteries were tested, one of which was intentionally defective (e.g., overcharging or discharging, or using it in extreme environments (high or low temperatures)) to degrade its cycle performance. The initial capacity of each battery was measured during testing. The test employed alternating full-discharge and non-full-discharge cycles. Non-full-discharge included discharge scenarios to 90% SOC, 80% SOC, 60% SOC, 40% SOC, and 10% SOC. That is, the secondary battery discharged from 100% SOC to 90% SOC, then after a period of time, discharged to 80% SOC, then after a period of time, discharged to 60% SOC, then after a period of time, discharged to 40% SOC, and finally after a period of time, discharged to 10% SOC. During the full-discharge test cycle, intermittent discharge is performed, with the discharge gaps meeting the SOH (State of Health) renewal conditions required for electronic device applications. This allows the secondary battery to renew its SOH after a certain number of cycles. The calculated relationship between the SOH of each secondary battery and the number of cycles (where the number of cycles is determined based on the actual SOC during charging or discharging) is as follows: Figure 5As shown. Due to non-full-charge cycling conditions, the State of Health (SOH) at 100 cycles cannot be accurately calculated for either of the two secondary batteries. SOH data close to 100 cycles were selected for each battery. Secondary battery 1 had 98 cycles and an SOH of 98.6; secondary battery 2 had 101 cycles and an SOH of 99.1. After the secondary batteries exceeded 150 cycles, the capacity slope k was calculated for each SOH update. The calculation results are shown below. Figure 6 .pass Figure 6 It is known that after 232.3 cycles (as known from experimental testing), the slope k of secondary battery 2 begins to exceed the pre-stored slope k0. At this point, the secondary battery capacity is determined to be abnormal. However, in actual operation, the electrolyte in this secondary battery is insufficient, and after a certain number of cycles, the electrolyte dries up, lithium plating occurs, and the secondary battery becomes excessively thick. Using the method in related technologies that determines the capacity of a secondary battery to be abnormal when its capacity is below a certain value (i.e., below 80% of the initial capacity), the secondary battery requires 363.6 cycles (as known from experimental testing) to detect the abnormality. However, the detection method shown in this application can detect the abnormality of the secondary battery 130 cycles earlier, avoiding the impact of the abnormal secondary battery on electronic devices.

[0074] This application also provides a battery management system connected to a secondary battery for managing the secondary battery. For example, the battery management system receives information from the secondary battery and various external interfaces, analyzes and processes the information, and then issues execution commands to complete functions such as charging, discharging, protection, equalization, fault detection, and fault warning for the secondary battery. Figure 7 As shown, the battery management system includes an information acquisition module and a processing module.

[0075] The information acquisition module is used to determine the capacity slope of the secondary battery in response to updating the SOH of the secondary battery, wherein the capacity slope characterizes the rate of change of the secondary battery capacity relative to the capacity of the reference secondary battery.

[0076] The processing module is used to determine whether the secondary battery capacity is abnormal based on the capacity slope and the preset capacity critical slope; wherein, the preset capacity critical slope represents the capacity slope when the secondary battery capacity is abnormal.

[0077] In one optional implementation, the information acquisition module is used to acquire the total number of charging or discharging cycles of the secondary battery in response to updating the SOH of the secondary battery, wherein if the proportion of the secondary battery capacity in a single charging or discharging cycle to the total capacity is greater than or equal to a first preset value, the total number of cycles is updated; and in response to the total number of cycles being greater than or equal to the preset number of cycles, the capacity slope of the secondary battery is determined.

[0078] In one optional implementation, the information acquisition module is used to determine the capacity slope of the secondary battery in response to each update of the SOH of the secondary battery if the total number of charging or discharging cycles of the secondary battery is greater than or equal to a preset number of cycles.

[0079] In one optional implementation, the information acquisition module is used to acquire the total number of charging or discharging cycles and the current capacity of the secondary battery; acquire a reference secondary battery capacity for a specified number of cycles within a preset reference cycle range, wherein the secondary battery capacity within the preset reference cycle range has no capacity decay, or the secondary battery capacity decay is less than a second preset value; and determine the capacity slope of the secondary battery based on the total number of cycles, the current secondary battery capacity, the specified cycle range, and the reference secondary battery capacity.

[0080] In one optional implementation, the information acquisition module is used to acquire the reference secondary battery capacity of each of multiple specified cycle numbers located within the preset reference cycle number range; wherein the cycle number interval between the multiple specified cycle numbers is not less than a third preset value; correspondingly, when determining the capacity slope of the secondary battery, the information acquisition module is used to obtain multiple capacity slopes of the secondary battery based on the total cycle number, the current secondary battery capacity, each specified cycle number and its corresponding reference secondary battery capacity; wherein one specified cycle number corresponds to one capacity slope; and the capacity slope of the secondary battery is determined based on the multiple capacity slopes.

[0081] In one optional implementation, the information acquisition module is used to acquire and save the number of charging or discharging cycles and the capacity of the secondary battery in response to each update of the SOH of the secondary battery.

[0082] The processing module is used to determine that the secondary battery capacity is abnormal if the difference between the capacity slope and the preset capacity critical slope is greater than a preset range; or if the difference between the capacity slope determined multiple times consecutively and the preset capacity critical slope is greater than a preset range, the secondary battery capacity is determined to be abnormal.

[0083] The processing module is configured to respond to an abnormal secondary battery capacity by indicating an abnormal secondary battery capacity and activating limiting measures; wherein the limiting measures include at least one of limiting the charging capacity of the secondary battery, limiting the number of times the secondary battery is charged, and limiting the maximum allowable current during secondary battery charging.

[0084] The principle and technical effect of abnormal secondary battery capacity detection provided by the battery management system embodiment are the same as those of the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in the battery management system embodiment can be referred to the corresponding content in the aforementioned method embodiment.

[0085] Based on the same inventive concept, this application also provides an electronic device, which includes a main body, a battery management system, and a secondary battery connected to the battery management system. The secondary battery includes at least one battery cell. The secondary battery is used to power the main body; the battery management system is used to execute the above-described secondary battery capacity anomaly detection method to achieve online monitoring of the secondary battery capacity.

[0086] The electronic device can be a laptop, tablet, smartphone, game console, drone, etc. It is understood that the electronic device is not limited to these; it can also be an electric device equipped with a secondary battery, such as an electric vehicle, electric bicycle, electric motorcycle, or electric car.

[0087] The principle and technical effects of abnormal secondary battery capacity detection provided in the electronic device embodiment are the same as those in the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in the electronic device embodiment can be referred to the corresponding content in the aforementioned method embodiment. This application embodiment also provides an electronic device, such as... Figure 8 As shown, the electronic device 200 includes: a transceiver 210, a memory 220, a communication bus 230, and a processor 240.

[0088] The transceiver 210, memory 220, and processor 240 are electrically connected directly or indirectly to achieve data transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses 230 or signal lines. The transceiver 210 is used to send and receive data. The memory 220 is used to store computer programs, which include at least one software function module that can be stored in the memory 220 in the form of software or firmware or embedded in the operating system (OS) of the electronic device 200. The processor 240 is used to execute the software function module or computer program stored in the memory 220. For example, the processor 240 can call the program stored in the memory 220 to execute the secondary battery capacity anomaly detection method described above.

[0089] The memory 220 may be, but is not limited to, random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.

[0090] Processor 240 may be an integrated circuit chip with signal processing capabilities. The aforementioned processor can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor, or processor 240 can be any conventional processor.

[0091] This application embodiment also provides a non-volatile computer-readable storage medium (hereinafter referred to as the storage medium) storing a computer program. When the computer program is run by a computer such as the electronic device 200 described above, it executes the above-described method for detecting abnormal secondary battery capacity.

[0092] This application also provides a computer program product, which includes a computer program. When the computer program is run by a processor, it executes the above-described method for detecting abnormal secondary battery capacity.

[0093] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0094] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0095] In addition, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0096] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they 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 computer-readable storage medium and includes several instructions to cause a computer device (which may be a personal computer, laptop, server, or electronic device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned computer-readable 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.

[0097] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for detecting abnormal capacity in secondary batteries, characterized in that, include: In response to updating the health status of the secondary battery, the capacity slope of the secondary battery is determined, wherein the capacity slope characterizes the rate of change of the capacity of the secondary battery relative to the capacity of a reference secondary battery; Based on the capacity slope and the preset capacity critical slope, determine whether the capacity of the secondary battery is abnormal; The preset capacity critical slope represents the capacity slope when the secondary battery capacity is abnormal.

2. The method according to claim 1, characterized in that, In response to updating the health status of the secondary battery, determining the capacity slope of the secondary battery includes: In response to updating the health status of the secondary battery, the total number of charging or discharging cycles of the secondary battery is obtained, wherein the proportion of the capacity of the secondary battery in a single charging or discharging cycle to the total capacity is greater than or equal to a first preset value, and then the total number of cycles is updated. In response to the total number of cycles being greater than or equal to a preset number of cycles, the capacity slope of the secondary battery is determined.

3. The method according to claim 1, characterized in that, In response to updating the health status of the secondary battery, determining the capacity slope of the secondary battery includes: If the total number of charging or discharging cycles of the secondary battery is greater than or equal to the preset number of cycles, the capacity slope of the secondary battery is determined in response to each update of the health status of the secondary battery.

4. The method according to any one of claims 1-3, characterized in that, Determining the capacity slope of the secondary battery includes: Get the total number of charging or discharging cycles of the current secondary battery and the current capacity of the secondary battery; Obtain the reference secondary battery capacity for a specified number of cycles within a preset reference cycle number range, wherein the secondary battery capacity within the preset reference cycle number range has no degradation, or the secondary battery capacity degradation is less than a second preset value; The capacity slope of the secondary battery is determined based on the total number of cycles, the current secondary battery capacity, the specified number of cycles, and the baseline secondary battery capacity.

5. The method according to claim 4, characterized in that, Obtaining the reference secondary battery capacity for a specified number of cycles within a preset reference cycle number range includes: Obtain the reference secondary battery capacity for each of multiple specified cycle numbers located within the preset reference cycle number range; wherein the cycle number interval between the multiple specified cycle numbers is not less than a third preset value; accordingly The capacity slope of the secondary battery is determined based on the total number of cycles, the current secondary battery capacity, the specified number of cycles, and the baseline secondary battery capacity, including: Based on the total number of cycles, the current secondary battery capacity, each specified number of cycles and its corresponding baseline secondary battery capacity, multiple capacity slopes of the secondary battery are obtained; wherein, each specified number of cycles corresponds to one capacity slope. The capacity slope of the secondary battery is determined based on the multiple capacity slopes.

6. The method according to claim 1, characterized in that, Determining whether the secondary battery capacity is abnormal based on the capacity slope and the preset capacity critical slope includes: If the difference between the capacity slope and the preset capacity critical slope is greater than a preset range, the secondary battery capacity is determined to be abnormal; or If the difference between the determined capacity slope and the preset capacity critical slope is greater than a preset range in multiple consecutive determinations, the secondary battery capacity is determined to be abnormal.

7. The method according to claim 1, characterized in that, The method further includes: In response to the abnormal capacity of the secondary battery, a notification of the abnormal capacity of the secondary battery is issued, and limiting measures are activated; The limiting measures include at least one of the following: limiting the charging capacity of the secondary battery, limiting the number of times the secondary battery is charged, or limiting the maximum allowable current when the secondary battery is charged.

8. The method according to claim 1, characterized in that, The method further includes: In response to each update of the secondary battery's health status, the number of charging or discharging cycles of the secondary battery and the secondary battery's capacity are acquired and saved.

9. A battery management system, characterized in that, include: An information acquisition module is used to determine the capacity slope of the secondary battery in response to updating the health status of the secondary battery, wherein the capacity slope characterizes the rate of change of the capacity of the secondary battery relative to the capacity of a reference secondary battery. The processing module is used to determine whether the capacity of the secondary battery is abnormal based on the capacity slope and the preset capacity critical slope. The preset capacity critical slope represents the capacity slope when the secondary battery capacity is abnormal.

10. An electronic device, characterized in that, include: A memory and a processor, wherein the processor is connected to the memory; The memory is used to store programs; The processor is configured to invoke a program stored in the memory to execute the method as described in any one of claims 1-8.

11. A computer-readable storage medium, characterized in that, It stores a computer program, which, when executed by a processor, performs the method as described in any one of claims 1-8.

12. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, performs the method as described in any one of claims 1-8.

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