Battery apparatus and battery pack test method

Abstract

A battery apparatus and a battery pack test method. The battery apparatus comprises a battery pack (10) and a battery management system (20). The battery pack (10) comprises a first battery set (100) having no platform area and a second battery set (101) having a platform area, and the first battery set (100) and the second battery set (101) are connected in series. The battery management system (20) is used for, on the basis of state of charge change data of the first battery set (100) in a current voltage interval, determining the current phase change capacity of the first battery set (100), so as to obtain the current battery state of health of the battery pack (10) on the basis of the battery state of health corresponding to a target phase change capacity matching the current phase change capacity among preset phase change capacities. The described battery apparatus and the battery pack test method can improve the accuracy of a battery pack test result.

Description

Battery device and battery pack testing methods Cross-reference to related applications

[0001] This application claims priority to Chinese patent application 202411822787.X, filed on December 11, 2024, entitled “Battery Device and Battery Pack Testing Method”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, specifically to a battery device and a battery pack testing method. Background Technology

[0003] To improve the stability of battery pack operation, it is usually necessary to test the battery pack, such as checking the battery health status or remaining capacity, in order to screen out abnormal battery packs.

[0004] In related technologies, battery pack testing is performed based on the SOC (state of charge) - OCV (open circuit voltage) curve. The SOC-OCV curve represents the relationship between the state of charge and the open circuit voltage. However, if the battery pack includes battery cells with plateau regions, the open circuit voltage of these battery cells varies very little in these regions, making it difficult to test the entire battery pack using the open circuit voltage of these individual battery cells. This affects the accuracy of the battery pack testing results. Summary of the Invention

[0005] In view of the above problems, this application provides a battery device and battery pack testing method, which can improve the accuracy of battery pack testing results.

[0006] In a first aspect, this application provides a battery device, including: a battery pack and a battery management system; the battery pack includes a first battery group without a plateau region and a second battery group with a plateau region, the first battery group and the second battery group being connected in series; the battery management system is used to determine the current phase change capacity of the first battery group based on the state of charge change data of the first battery group under a current voltage range, so as to obtain the current battery health state of the battery pack based on the battery health state corresponding to a target phase change capacity that matches the current phase change capacity among each preset phase change capacity; wherein, the current voltage range includes a charging voltage range or a discharging voltage range; the preset phase change capacity corresponding to any of the battery health states is determined based on the correspondence between the open circuit voltage and the state of charge measured by charging and discharging cycles of a battery sample in the battery health state, the battery sample being of the same battery type as the first battery group.

[0007] In the technical solution of this application embodiment, by introducing a first battery pack without a plateau region and connecting it in series with a second battery pack having a plateau region, the current phase change capacity of the first battery pack can be determined based on the state of charge change data of the first battery pack in the charging voltage range or the discharging voltage range. Then, based on the battery health state corresponding to the target phase change capacity that matches the current phase change capacity among each preset phase change capacity, the current battery health state of the battery pack can be obtained. Thus, the state of the battery pack can be estimated by the changes in the state of charge and open circuit voltage of the battery pack without a plateau region in a certain voltage range, without having to consider the open circuit voltage changes of the battery pack with a plateau region, thereby improving the accuracy of the battery pack detection results.

[0008] In some embodiments, the battery management system is specifically configured to: obtain the SOC-OCV curve of the first battery pack in the current voltage range based on the state-of-charge change data of the first battery pack in the current voltage range; and determine the current phase change capacity of the first battery pack based on the slope of the SOC-OCV curve. This makes the obtained current phase change capacity of the first battery pack more accurate, improves the reliability of the current battery health status of the battery pack determined using the current phase change capacity, and further improves the accuracy of battery pack detection.

[0009] In some embodiments, the battery management system is further configured to: obtain at least one candidate phase change capacity matching the current phase change capacity from each of the preset phase change capacities; and, based on the charge / discharge cycle counts corresponding to each candidate phase change capacity, obtain a target phase change capacity from each candidate phase change capacity whose charge / discharge cycle count has the smallest difference from the current charge / discharge cycle count of the battery pack. Since the charge / discharge cycle count corresponding to the target phase change capacity is closest to the current charge / discharge cycle count of the battery pack, the battery health state corresponding to the target phase change capacity is closer to the current battery health state of the battery pack, thereby improving the accuracy of the detected current battery health state of the battery pack.

[0010] In some embodiments, the battery management system is specifically configured to: determine the current battery health status of the first battery pack based on the battery health status corresponding to the target phase change capacity that matches the current phase change capacity among each preset phase change capacity; determine the current battery health status of the second battery pack based on the current battery health status of the first battery pack and the ratio of the battery health status of the first battery pack to that of the second battery pack; and obtain the current battery health status of the battery pack based on the current battery health status of the first battery pack and the current battery health status of the second battery pack, thereby enabling the determination of the current battery health status of the battery pack by combining the current battery health status of the first battery pack and the second battery pack, thus improving the reliability of battery pack detection.

[0011] In some embodiments, the battery management system is specifically configured to: obtain the current battery health state of the battery pack based on the minimum value between the current battery health state of the first battery pack and the current battery health state of the second battery pack. This reduces the likelihood that the detected battery health state of the battery pack is greater than the actual battery health state, and even if the detected battery health state is greater than the actual battery health state, it can reduce the error between the two, thereby further improving the reliability of battery pack detection.

[0012] In some embodiments, the battery management system is further configured to: if it is determined that the product information of the first battery pack is the same as that of the battery sample, then determine the current remaining capacity of the battery pack based on the state of charge of the battery sample in the battery health state corresponding to the target phase change capacity and the current open circuit voltage of the first battery pack, thereby eliminating the need to consider the open circuit voltage change of the battery pack with a plateau region and eliminating the need to perform deep charge and discharge on the battery pack to estimate the current remaining capacity of the battery pack, thereby improving the accuracy and efficiency of the battery pack detection results.

[0013] In some embodiments, the battery sample is a sample of a single cell; the battery management system is further configured to: obtain a target open-circuit voltage based on the current open-circuit voltage of the first battery pack and the number of cell strings in the first battery pack; determine the current remaining capacity of the battery pack based on the state of charge of the battery sample in the battery health state corresponding to the target phase change capacity and the state of charge corresponding to the target open-circuit voltage, thereby estimating the current remaining capacity of the battery pack by using the average open-circuit voltage of each cell in the first battery pack, avoiding the situation where the consistency difference between each cell leads to a large error in the current remaining capacity estimation, and further improving the accuracy of the detected current remaining capacity of the battery pack.

[0014] In some embodiments, the available capacity of the first battery pack during the usage period of the second battery pack is equal to the available capacity of the second battery pack during the usage period.

[0015] In some embodiments, the first battery pack is a polyanion battery pack, and the second battery pack is a lithium iron phosphate battery pack; the charging rate provided to the first battery pack is greater than the charging rate provided to the second battery pack.

[0016] Secondly, this application provides a battery pack detection method, applied to the battery device in any of the above embodiments. The battery pack detection method includes: determining the current phase change capacity of the first battery pack based on the state of charge change data of the first battery pack under a current voltage range; obtaining the current battery health state of the battery pack based on the battery health state corresponding to a target phase change capacity that matches the current phase change capacity among various preset phase change capacities; wherein, the current voltage range includes a charging voltage range or a discharging voltage range; the preset phase change capacity corresponding to any of the battery health states is determined based on the correspondence between the open circuit voltage and the state of charge measured by charging and discharging cycles on a battery sample in the battery health state, wherein the battery sample is of the same battery type as the first battery pack.

[0017] In the technical solution of this application embodiment, by introducing a first battery pack without a plateau region and connecting it in series with a second battery pack having a plateau region, the current phase change capacity of the first battery pack can be determined based on the state of charge change data of the first battery pack in the charging voltage range or the discharging voltage range. Then, based on the battery health state corresponding to the target phase change capacity that matches the current phase change capacity among each preset phase change capacity, the current battery health state of the battery pack can be obtained. Thus, the state of the battery pack can be estimated by the changes in the state of charge and open circuit voltage of the battery pack without a plateau region in a certain voltage range, without having to consider the open circuit voltage changes of the battery pack with a plateau region, thereby improving the accuracy of the battery pack detection results.

[0018] Secondly, this application provides a battery pack testing device, applied to the battery device in any of the above embodiments. The battery pack testing device includes: a capacity detection module, used to determine the current phase change capacity of the first battery pack based on the state of charge change data of the first battery pack under a current voltage range; and a battery pack testing module, used to obtain the current battery health state of the battery pack based on the battery health state corresponding to a target phase change capacity that matches the current phase change capacity among various preset phase change capacities; wherein the current voltage range includes a charging voltage range or a discharging voltage range; and the preset phase change capacity corresponding to any of the battery health states is determined based on the correspondence between the open-circuit voltage and the state of charge measured by charging and discharging cycles on a battery sample in the battery health state, wherein the battery sample is of the same battery type as the first battery pack.

[0019] In the technical solution of this application embodiment, by introducing a first battery pack without a plateau region and connecting it in series with a second battery pack having a plateau region, the current phase change capacity of the first battery pack can be determined based on the state of charge change data of the first battery pack in the charging voltage range or the discharging voltage range. Then, based on the battery health state corresponding to the target phase change capacity that matches the current phase change capacity among each preset phase change capacity, the current battery health state of the battery pack can be obtained. Thus, the state of the battery pack can be estimated by the changes in the state of charge and open circuit voltage of the battery pack without a plateau region in a certain voltage range, without having to consider the open circuit voltage changes of the battery pack with a plateau region, thereby improving the accuracy of the battery pack detection results.

[0020] Thirdly, this application provides an electronic device including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the method described in the second aspect of the embodiment.

[0021] Fourthly, this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, performs the method described in the second aspect of the embodiment.

[0022] Fifthly, this application provides a computer program product that, when run on a computer, causes the computer to perform the method described in the implementation of the second aspect.

[0023] In a sixth aspect, this application provides a battery management system, including a processor and a memory storing a computer program, which, when executed by the processor, implements the method described in the implementation of the second aspect.

[0024] In a seventh aspect, the application provides an electrical device including the battery device described in the first aspect, or the battery management system described in the sixth aspect.

[0025] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0026] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0027] Figure 1 is a schematic diagram of the battery device structure according to some embodiments of this application;

[0028] Figure 2 is a schematic diagram of the battery pack structure of some embodiments of this application;

[0029] Figure 3 is a schematic diagram of the SOC-OCV curves of the second battery pack in some embodiments of this application;

[0030] Figure 4 is a schematic diagram of the SOC-OCV curves of the first battery pack in some embodiments of this application under the current voltage range;

[0031] Figure 5 is a flowchart of a battery pack detection method according to some embodiments of this application;

[0032] Figure 6 is a schematic diagram of the structure of a battery pack detection device according to some embodiments of this application;

[0033] Figure 7 is a schematic diagram of the structure of an electronic device according to some embodiments of this application.

[0034] The reference numerals in the detailed embodiments are as follows:

[0035] 10-Battery pack; 20-Battery management system; 100-First battery pack; 101-Second battery pack; 200-Capacity detection module; 201-Battery pack detection module; 300-Electronic device; 301-Processor; 302-Memory; 303-Communication bus. Detailed Implementation

[0036] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0038] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0039] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0040] In the description of the embodiments in this application, the term "and / or" is merely a description of the 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. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0041] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0042] To improve the stability of battery pack operation, it is usually necessary to test the battery pack, such as checking the battery health status or remaining capacity, in order to screen out abnormal batteries.

[0043] In related technologies, battery pack testing is performed based on the SOC-OCV curve of the battery pack. The SOC-OCV curve represents the relationship between the state of charge and the open-circuit voltage. However, if the battery pack includes battery groups with plateau regions, such as those composed of lithium iron phosphate batteries, the open-circuit voltage change corresponding to each 1% change in SOC in these plateau regions is less than 1mV. This very small change makes it difficult to test the battery pack based solely on the open-circuit voltage of these battery groups, affecting the accuracy of the battery pack testing results.

[0044] To address the aforementioned technical issues, this application's embodiments introduce a first battery pack without a plateau region, connected in series with a second battery pack having a plateau region. This allows the current phase change capacity of the first battery pack to be determined based on its state of charge (SOC) changes within a charging or discharging voltage range. Then, based on the battery health status corresponding to the target SOC that matches the current SOC among preset SOCs, the current battery health status of the battery pack can be obtained. This allows for the estimation of the battery pack's state of charge and open-circuit voltage changes within a certain voltage range using the SOC and open-circuit voltage changes of the battery pack without a plateau region, thereby improving the accuracy of battery pack detection results.

[0045] Furthermore, battery pack testing can be performed without deep charging and discharging, improving the efficiency of battery pack testing.

[0046] According to some embodiments of this application, a battery device is provided, as shown in FIG1. ​​The battery device includes a battery pack 10 and a battery management system 20. The battery pack 10 is connected to the battery management system 20. The battery pack 10 includes a first battery group 100 without a platform area and a second battery group 101 with a platform area. The first battery group 100 and the second battery group 101 are connected in series, as shown in FIG2.

[0047] The battery management system 20 is used to determine the current phase change capacity of the first battery pack 100 based on the state of charge change data of the first battery pack 100 in the current voltage range, so as to obtain the current battery health status of the battery pack based on the battery health status corresponding to the target phase change capacity that matches the current phase change capacity among the preset phase change capacities.

[0048] The current voltage range includes either a charging voltage range or a discharging voltage range;

[0049] The preset phase change capacity corresponding to any of the battery health states is determined based on the correspondence between the open-circuit voltage and the state of charge obtained by charging and discharging a battery sample in the battery health state, wherein the battery sample is of the same type as the battery in the first battery pack 100.

[0050] In some embodiments, the first battery pack 100 may include at least one individual battery cell without a plateau region. For example, the first battery pack 100 may be composed of a single individual battery cell without a plateau region; or, the first battery pack 100 may be composed of multiple individual batteries cell cells without plateau regions connected in series, parallel, or series-parallel. The second battery pack 101 may include at least one individual battery cell with a plateau region. For example, the second battery pack 101 may be composed of a single individual battery cell with a plateau region; or, the second battery pack 101 may be composed of multiple individual batteries cell cells with plateau regions connected in series, parallel, or series-parallel.

[0051] For example, the first battery pack 100 may be composed of ternary lithium batteries, polyanion sodium-ion batteries or other batteries without a plateau region, and the second battery pack 101 may be composed of lithium iron phosphate batteries.

[0052] Taking a single cell in the second battery pack 101, including a lithium iron phosphate battery, as an example, its SOC-OCV curve during a full charge is shown in Figure 3. As shown in Figure 3, the SOC-OCV curve of the second battery pack 101 has two plateau regions. In the portion of the curve corresponding to these plateau regions, the open-circuit voltage remains essentially constant, making it difficult to detect the state of the battery pack 10 using the open-circuit voltage of the second battery pack 101. Since the first battery pack 100 does not have plateau regions, in some embodiments, when it is necessary to detect the battery pack 10, the battery management system 20 can obtain the change in state of charge (SOC) of the first battery pack 100 corresponding to each open-circuit voltage within the current voltage range, thereby obtaining the SOC change data of the first battery pack 100 within the current voltage range. For example, assuming the current voltage range is a charging voltage range of 3V-3.1V, the battery management system 20 can obtain the change in the state of charge of the first battery pack 100 during the process of charging the open circuit voltage from 3V to 3.1V, so as to obtain the change data of the state of charge of the first battery pack 100 with the change of open circuit voltage under the current voltage range.

[0053] After obtaining the state of charge (SOC) change data of the first battery pack 100, the SOC change amount ΔSOC1 corresponding to a certain open-circuit voltage V1 and the SOC change amount ΔSOC2 corresponding to another open-circuit voltage V2 can be obtained from the SOC change data. Based on the open-circuit voltage V1, the SOC change amount ΔSOC1, the open-circuit voltage V2, and the SOC change amount ΔSOC2, the current phase change capacity of the first battery pack 100 is calculated as (V2-V1) / (ΔSOC2-ΔSOC1). Here, the current phase change capacity refers to the capacity of the first battery pack 100 during the current material phase change.

[0054] For example, assuming the current voltage range is a charging voltage range of 3V-3.1V, the change in state of charge (SOC) of the first battery pack 100 can be obtained when the open-circuit voltage of the first battery pack 100 is 3V, and the change in SOC of the first battery pack 100 can be obtained when the open-circuit voltage of the first battery pack 100 is 3.1V. Since 3V is the starting point of the current voltage range, it can be known that when the open-circuit voltage is 3V, the change in SOC of the first battery pack 100 is 0. At this time, the current phase change capacity of the first battery pack 100 can be determined to be (V2-V1) / ΔSOC2.

[0055] After obtaining the current phase change capacity of the first battery pack 100, the target phase change capacity can be determined from the database containing different preset phase change capacities and the battery health status corresponding to different preset phase change capacities. For example, the preset phase change capacity closest to the current phase change capacity can be determined as the target phase change capacity.

[0056] The preset phase change capacity can be obtained by performing charge-discharge cycles on a battery sample in a healthy state. This battery sample is of the same type as the battery in the first battery pack 100. For example, if the first battery pack 100 is a polyanion battery, then the battery sample is also a polyanion battery.

[0057] For example, a charge-discharge cycle can be performed on a battery sample in a certain battery health state, and the correspondence between the open-circuit voltage and the state of charge (SOC-OCV curve) during charging and discharging can be detected. After obtaining the SOC-OCV curves during charging and discharging, the slope of the SOC-OCV curve during charging can be mapped as a preset phase change capacity to the battery health state, and the slope of the SOC-OCV curve during discharging can be mapped as another preset phase change capacity to the battery health state to obtain the preset phase change capacity corresponding to the battery sample in that battery health state. Alternatively, a charge-discharge cycle can be performed on multiple battery samples in a certain battery health state, and the SOC-OCV curves of each battery sample during charging and discharging can be detected. After obtaining the SOC-OCV curves of each battery sample during charging and discharging, the average slope of the SOC-OCV curves during charging can be used as a preset phase change capacity and mapped to the battery's health state. Similarly, the average slope of the SOC-OCV curves during discharging can be used as another preset phase change capacity and mapped to the same battery health state. This yields the preset phase change capacity corresponding to each battery sample under its specific health state. By repeating this process, the preset phase change capacity for each battery sample under any given battery health state can be obtained, thus determining the battery health state corresponding to different preset phase change capacities.

[0058] After obtaining the target phase change capacity that matches the current phase change capacity of the first battery pack 100 from the preset phase change capacities, since the target phase change capacity matches the current phase change capacity of the first battery pack 100, the battery health state corresponding to the target phase change capacity can reflect the battery health state corresponding to the current phase change capacity of the first battery pack 100. At this point, the battery health state corresponding to the target phase change capacity can be determined as the current battery health state of the first battery pack 100, and the current battery health state of the battery pack 10 can be obtained based on the current battery health state of the first battery pack 100, thereby realizing the state detection of the battery pack 10. For example, the current battery health state of the first battery pack 100 can be used as the current battery health state of the battery pack 10. If the first battery pack 100 is a polyanion battery pack and the second battery pack 101 is a lithium iron phosphate battery pack, since the battery lifespans of polyanion batteries and lithium iron phosphate batteries are similar, the current battery health state of the battery pack 10 obtained using the current battery health state of the first battery pack 100 is more accurate.

[0059] By introducing a first battery pack 100 without a plateau region and connecting it in series with a second battery pack 101 having a plateau region, the current phase change capacity of the first battery pack 100 can be determined based on the change data of the state of charge of the first battery pack 100 in the charging voltage range or the discharging voltage range. Then, based on the battery health status corresponding to the target phase change capacity that matches the current phase change capacity among the preset phase change capacities, the current battery health status of the battery pack 10 can be obtained. Thus, the state of the battery pack 10 can be predicted by the change of the state of charge and open circuit voltage of the battery pack without a plateau region in a certain voltage range, without having to consider the change of the open circuit voltage of the battery pack with a plateau region, thereby improving the accuracy of the detection results of the battery pack 10.

[0060] Furthermore, the detection of the battery pack 10 can be achieved without deep charging and discharging, which improves the detection efficiency of the battery pack 10.

[0061] To improve the accuracy of battery pack 10 detection, the battery management system 20 is specifically used to: obtain the SOC-OCV curve of the first battery pack 100 in the current voltage range based on the state of charge change data of the first battery pack 100 in the current voltage range; and determine the current phase change capacity of the first battery pack 100 based on the slope of the SOC-OCV curve.

[0062] In some embodiments, after acquiring the state-of-charge (SOC) change data of the first battery pack 100 under the current voltage range as the open-circuit voltage changes, the battery management system 20 can generate the SOC-OCV curve of the first battery pack 100 in the current voltage range based on the SOC change amount corresponding to any open-circuit voltage in the SOC change data. For example, assuming the current voltage range is a charging voltage range of 3V-3.1V, the obtained SOC-OCV curve of the first battery pack 100 in this charging voltage range can be shown in Figure 4.

[0063] After obtaining the SOC-OCV curve of the first battery pack 100 in the current voltage range, since the slope of the SOC-OCV curve is used to characterize the capacity of the material phase change, i.e. the phase change capacity of the material, the slope of the SOC-OCV curve can be calculated and used as the current phase change capacity of the first battery pack 100. This makes the obtained current phase change capacity of the first battery pack 100 more accurate, improves the reliability of the current battery health status of the battery pack 10 determined by the current phase change capacity, and further improves the accuracy of the battery pack 10 detection.

[0064] After determining the current phase change capacity of the first battery pack 100, the current phase change capacity can be matched with each preset phase change capacity, and the preset phase change capacity that matches the current phase change capacity can be determined as the target phase change capacity. Based on the battery health status corresponding to the target phase change capacity, the current battery health status of the battery pack 10 can be obtained.

[0065] Considering that different battery health states may correspond to the same preset phase change capacity among the preset phase change capacities, the current phase change capacity may match multiple preset phase change capacities, making it impossible to accurately determine the current battery health state of the battery pack 10. Therefore, in some embodiments, the battery management system 20 is further configured to: obtain at least one candidate phase change capacity that matches the current phase change capacity from among the preset phase change capacities; and, based on the charge / discharge cycle counts corresponding to each candidate phase change capacity, obtain the target phase change capacity from among the candidate phase change capacities whose charge / discharge cycle count has the smallest difference from the current charge / discharge cycle count of the battery pack.

[0066] In some embodiments, since the preset phase change capacity is determined by the SOC-OCV curve obtained from charging and discharging cycles of the battery sample, each preset phase change capacity corresponds to a number of charging and discharging cycles, indicating which charge-discharging cycle the preset phase change capacity was determined by. For example, if a battery sample is in a certain battery health state and the number of charge-discharging cycles is 100, then the SOC-OCV curve at the 100th charge-discharging cycle can be obtained, and the preset phase change capacity corresponding to the 100th charge-discharging cycle can be obtained based on the SOC-OCV curve.

[0067] The battery management system 20 can match the current phase change capacity of the first battery pack 100 with each preset phase change capacity, and determine the preset phase change capacity that matches the current phase change capacity as the candidate phase change capacity.

[0068] If only a single candidate phase change capacity is matched, that candidate phase change capacity can be determined as the target phase change capacity. Based on the battery health status corresponding to the target phase change capacity, the current battery health status of battery pack 10 can be determined. If multiple candidate phase change capacities are matched, the charge / discharge cycle count Kn corresponding to each candidate phase change capacity can be compared with the current charge / discharge cycle count K of battery pack 10 to obtain the cycle difference ΔKn between each charge / discharge cycle count Kn and the current charge / discharge cycle count K, such as ΔKn=|Kn-K|. Here, Kn represents the charge / discharge cycle count corresponding to the nth candidate phase change capacity, and ΔKn represents the cycle difference between the charge / discharge cycle count corresponding to the nth candidate phase change capacity and the current charge / discharge cycle count. The current charge / discharge cycle count of battery pack 10 refers to the accumulated charge / discharge cycle count of battery pack 10 up to the current moment.

[0069] After obtaining the number of charge / discharge cycles corresponding to each candidate phase change capacity and the difference between that number and the current number of charge / discharge cycles of battery pack 10, the number of charge / discharge cycles corresponding to the smallest difference can be used as the target number of charge / discharge cycles. The candidate phase change capacity corresponding to this target number of charge / discharge cycles is then determined as the target phase change capacity. For example, if each candidate phase change capacity includes candidate phase change capacity A and candidate phase change capacity B, and candidate phase change capacity A corresponds to 100 charge / discharge cycles, candidate phase change capacity B corresponds to 600 charge / discharge cycles, and the current number of charge / discharge cycles of battery pack 10 is 500, then candidate phase change capacity B can be determined as the target phase change capacity.

[0070] Since the number of charge-discharge cycles corresponding to the target phase change capacity is closest to the current number of charge-discharge cycles of the battery pack 10, the battery health state corresponding to the target phase change capacity is closer to the current battery health state of the battery pack 10, thereby improving the accuracy of detecting the current battery health state of the battery pack 10.

[0071] Considering that the battery health status corresponding to the target phase change capacity matching the current phase change capacity represents the battery health status of the first battery pack 100, and that the battery health status of the first battery pack 100 and the second battery pack 101 may differ, directly determining the battery health status of the first battery pack 100 as the battery health status of the battery pack 10 would affect the reliability of the battery pack 10 detection. Therefore, in some embodiments, the battery management system 20 is specifically used to: determine the current battery health status of the first battery pack 100 based on the battery health status corresponding to the target phase change capacity matching the current phase change capacity among each preset phase change capacity; determine the current battery health status of the second battery pack 101 based on the current battery health status of the first battery pack 100 and the ratio of the battery health status of the first battery pack 100 to that of the second battery pack 101; and obtain the current battery health status of the battery pack 10 based on the current battery health status of the first battery pack 100 and the current battery health status of the second battery pack 101.

[0072] In some embodiments, the battery management system 20 may pre-store the battery health ratios of the first battery pack 100 and the second battery pack 101. For example, assuming the first battery pack 100 is a polyanion battery pack and the second battery pack 101 is a lithium iron phosphate battery pack, if the battery life of the first battery pack 100 within the operating range of the second battery pack 101 is 1.05-1.2 times the battery life of the second battery pack 101, then the first battery pack 100 with a battery life 1.05-1.2 times that of the second battery pack 101 can be connected in series with the second battery pack 101. In this case, the battery health ratio of the first battery pack 100 to the second battery pack 101 is 1.05-1.2 times.

[0073] After obtaining the target phase change capacity that matches the current phase change capacity of the first battery pack 100 from the preset phase change capacities, the battery health state corresponding to the target phase change capacity can be determined as the current battery health state of the first battery pack 100. Since the ratio of the battery health states of the first battery pack 100 and the second battery pack 101 is determined, the current battery health state of the second battery pack 101 can also be obtained based on the current battery health state of the first battery pack 100 and the ratio of the battery health states of the first battery pack 100 and the second battery pack 101.

[0074] As one possible implementation, after obtaining the current battery health status of the first battery pack 100 and the current battery health status of the second battery pack 101, the average value of the current battery health status of the first battery pack 100 and the current battery health status of the second battery pack 101 can be determined as the current battery health status of the battery pack 10. This reduces the error between the detected battery health status of the battery pack 10 and the actual battery health status, and improves the reliability of the battery pack 10 detection.

[0075] As another possible implementation, the current battery health state of the first battery pack 100 can be compared with the current battery health state of the second battery pack 101. If the current battery health state of the first battery pack 100 is greater than the current battery health state of the second battery pack 101, then the average value of the current battery health state of the first battery pack 100 and the current battery health state of the second battery pack 101 is determined as the current battery health state of the battery pack 10. If the current battery health state of the first battery pack 100 is less than the current battery health state of the second battery pack 101, then the current battery health state of the first battery pack 100 is determined as the current battery health state of the battery pack 10.

[0076] The current battery health status of the first battery pack 100 is determined by identifying the battery health status corresponding to the target phase change capacity that matches the current phase change capacity among the preset phase change capacities. Furthermore, the current battery health status of the second battery pack 101 is determined based on the current battery health status of the first battery pack 100 and the ratio of the battery health status of the first battery pack 100 to that of the second battery pack 101. This allows for the determination of the current battery health status of the battery pack 10 by combining the current battery health statuses of the first battery pack 100 and the second battery pack 101, thereby improving the reliability of the battery pack 10 detection.

[0077] To further improve the reliability of battery pack 10 detection, the battery management system 20 is specifically used to: obtain the current battery health status of the battery pack 10 based on the minimum value between the current battery health status of the first battery pack 100 and the current battery health status of the second battery pack 101.

[0078] In some embodiments, the battery management system 20 may use the minimum value between the current battery health state of the first battery pack 100 and the current battery health state of the second battery pack 101 as the current battery health state of the battery pack 10. If the current battery health state of the first battery pack 100 is greater than the current battery health state of the second battery pack 101, then the current battery health state of the second battery pack 101 is determined as the current battery health state of the battery pack 10; if the current battery health state of the first battery pack 100 is less than the current battery health state of the second battery pack 101, then the current battery health state of the first battery pack 100 is determined as the current battery health state of the battery pack 10. This reduces the possibility that the detected battery health state of the battery pack 10 is greater than the actual battery health state, and even if the detected battery health state of the battery pack 10 is greater than the actual battery health state, the error between the two can be reduced, thereby further improving the reliability of the battery pack 10 detection.

[0079] In addition to detecting the battery health status of the battery pack 10, in some embodiments, the battery management system 20 is also used to: if it is determined that the product information of the first battery pack 100 is the same as that of the battery sample, then determine the current remaining capacity of the battery pack 10 based on the state of charge of the battery sample corresponding to the current open circuit voltage of the first battery pack 100 under the battery health status corresponding to the target phase change capacity.

[0080] The product information may include battery type, battery connection method, and number of batteries. For example, if the first battery pack 100 and the battery sample are both composed of the same number of polyanion sodium-ion batteries connected in series, then it can be determined that the first battery pack 100 and the battery sample have the same product information.

[0081] In some embodiments, the battery management system 20 can detect whether the product information of the first battery pack 100 is the same as that of the battery sample. If the product information of the first battery pack 100 is the same as that of the battery sample, it means that the SOC-OCV curve used to generate the target phase change capacity in the battery health state corresponding to the target phase change capacity can characterize the SOC-OCV curve of the first battery pack 100 in the battery health state. At this time, the state of charge corresponding to the current open circuit voltage of the first battery pack 100 can be found from the SOC-OCV curve based on the current open circuit voltage of the first battery pack 100, and used as the current state of charge of the first battery pack 100, so as to determine the current remaining capacity of the battery pack 10. If the current state of charge of the first battery pack 100 is determined as the current remaining capacity of the battery pack 10, then the open circuit voltage change of the battery pack with the plateau region does not need to be considered, and the current remaining capacity of the battery pack 10 can be estimated without performing deep charge and discharge on the battery pack 10, thereby improving the accuracy and efficiency of the detection results of the battery pack 10.

[0082] To further improve the accuracy of the detected current remaining capacity of the battery pack 10, in some embodiments, the battery sample is a sample of a single cell.

[0083] The battery management system 20 is also used for:

[0084] The target open-circuit voltage is obtained based on the current open-circuit voltage of the first battery pack 100 and the number of battery strings in the first battery pack 100; the current remaining capacity of the battery pack 10 is determined based on the state of charge of the battery sample in the battery health state corresponding to the target phase change capacity and the state of charge corresponding to the target open-circuit voltage.

[0085] The number of battery strings in the first battery pack 100 refers to the number of batteries connected in series in the first battery pack 100.

[0086] In some embodiments, the battery management system 20 can obtain the current open-circuit voltage of the first battery pack 100, and based on the current open-circuit voltage and the number of battery strings in the first battery pack 100, obtain the current open-circuit voltage of a single cell in the first battery pack 100, so as to determine the current open-circuit voltage of a single cell in the first battery pack 100 as a target open-circuit voltage. For example, assuming the current open-circuit voltage of the first battery pack 100 is V and the number of battery strings in the first battery pack 100 is H, the target open-circuit voltage V' = V / H can be obtained.

[0087] Since the battery sample is a single cell sample, and the battery sample is of the same type as the battery in the first battery pack 100, the battery sample, under the battery health state corresponding to the target phase change capacity, is used to generate the SOC-OCV curve of the target phase change capacity. This curve can characterize the SOC-OCV curve of a single cell in the first battery pack 100 under this battery health state. At this time, based on the current open-circuit voltage of the single cell, i.e., the target open-circuit voltage, the state of charge corresponding to the target open-circuit voltage can be found from the SOC-OCV curve and used as the current state of charge of the single cell in the first battery pack 100. Therefore, the current remaining capacity of the battery pack 10 can be determined based on the current state of charge of the single cell in the first battery pack 100. For example, the current state of charge of the single cell in the first battery pack 100 is determined as the current remaining capacity of the battery pack 10. Therefore, the current remaining capacity of the battery pack 10 can be estimated by using the average open-circuit voltage of each individual cell in the first battery pack 100, avoiding the situation where the inconsistency between individual cells leads to a large error in the current remaining capacity estimation, thereby further improving the accuracy of the detected current remaining capacity of the battery pack 10.

[0088] Considering that the usage ranges of the first battery pack 100 and the second battery pack 101 may be different, and part of the capacity of the first battery pack 100 may be unusable, in order to reduce the occurrence of situations where the normal operation of the battery pack 10 is affected by the unusable capacity of the first battery pack 100, in some embodiments, the available capacity of the first battery pack 100 in the usage range of the second battery pack 101 is equal to the available capacity of the second battery pack 101 in the usage range.

[0089] For example, taking the first battery pack 100 as a polyanion battery pack composed of sodium-ion polyanion batteries and the second battery pack 101 as a lithium iron phosphate battery pack composed of lithium iron phosphate batteries, the capacity of a single sodium-ion polyanion battery is 110Ah, with an operating range of 1.5V-3.8V, while the capacity of a single lithium iron phosphate battery is 100Ah, with an operating range of (2.5-3.65)V. Since the operating range of the sodium-ion batteries is wider than that of the lithium iron phosphate batteries, to avoid the partial unusable capacity of the sodium-ion polyanion battery pack affecting the normal operation of the battery pack 10, the capacities of both batteries must be set to be equal to the usable capacity of the sodium-ion polyanion battery pack within the operating range of the lithium iron phosphate battery pack. To ensure that the usable capacity of the polyanion sodium-ion battery pack within the operating range of the lithium iron phosphate battery pack is equal to that of the lithium iron phosphate battery pack within the same operating range, individual polyanion sodium-ion batteries can be selected to form a polyanion sodium-ion battery pack, which is then connected in series with all the lithium iron phosphate batteries in the lithium iron phosphate battery pack. The operating range of the lithium iron phosphate battery pack is (2.5-3.65)V, and in this range, the usable capacity of the sodium-ion battery pack is equal to that of the lithium iron phosphate battery pack.

[0090] Alternatively, taking a first battery pack 100 composed of sodium iron sulfate batteries and a second battery pack 101 composed of lithium iron phosphate batteries as an example, the sodium iron sulfate batteries have a capacity of 110 Ah and an operating range of (1.5-4.2) V, while the lithium iron phosphate batteries have a capacity of 100 Ah and an operating range of (2.5-3.65) V. In this case, four sodium iron sulfate batteries can be connected in parallel to form a sodium iron sulfate battery pack, and five lithium iron phosphate batteries can be connected in parallel to form a lithium iron phosphate battery pack. The operating range of the sodium iron sulfate battery pack is (3.125-4.2) V, and the operating range of the lithium iron phosphate battery pack is (2.5-3.36) V. Connecting the sodium iron sulfate battery pack and the lithium iron phosphate battery pack in series results in the same usable capacity of the sodium iron sulfate battery pack within the operating range of the lithium iron phosphate battery pack.

[0091] By setting the available capacity of the first battery pack 100 in the usage range of the second battery pack 101 to be equal to the available capacity of the second battery pack 101 in the same usage range, the first battery pack 100 and the second battery pack 101 can use the same capacity when the battery pack 10 is running. This reduces the occurrence of situations where the normal operation of the battery pack 10 is affected by the inability to use part of the capacity of the first battery pack 100, thereby improving the reliability of the battery pack 10.

[0092] Considering the significant difference in lifespan between ternary lithium batteries and lithium iron phosphate batteries, in some embodiments, the first battery pack 100 may be a polyanion battery pack, and the second battery pack 101 may be a lithium iron phosphate battery pack.

[0093] The polyanion battery pack can be composed of multiple polyanion batteries, such as multiple polyanion sodium-ion batteries connected in series, parallel, or series-parallel. Similarly, the lithium iron phosphate battery pack can be composed of multiple lithium iron phosphate batteries connected in series, parallel, or series-parallel. For example, the polyanion battery pack includes a sodium-ion battery pack using a polyanion compound as the positive electrode material. The polyanion compound can include at least one of sodium vanadium phosphate, sodium titanium phosphate, or a composite sodium iron phosphate. For instance, the polyanion battery pack can be a sodium-ion battery pack using a composite sodium iron phosphate as the positive electrode material. Since the lifespan of polyanion batteries is similar to or even longer than that of lithium iron phosphate batteries, the state of the polyanion batteries can be used to predict the state of the lithium iron phosphate batteries, thereby detecting the state of the entire battery pack and improving the accuracy of the detected battery pack state.

[0094] In some embodiments, since polyanion batteries typically use hard carbon as the negative electrode, their charging rate at low SOC is far greater than that of lithium iron phosphate batteries using graphite negative electrodes. However, at low temperatures, the charging rate of polyanion batteries at high SOC is not as good as that of lithium iron phosphate batteries. Therefore, if the first battery pack 100 is a polyanion battery pack and the second battery pack 101 is a lithium iron phosphate battery pack, the charging rate provided to the first battery pack 100 is greater than the charging rate provided to the second battery pack 101. That is, during the charging process of the battery pack, the charging rate provided to the first battery pack 100 at any SOC is greater than the charging rate provided to the second battery pack 101 at that SOC.

[0095] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below. In some embodiments, as shown in FIG1, a battery device is provided, including a battery pack 10 and a battery management system 20; the battery pack 10 is connected to the battery management system 20; the battery pack 10 includes a first battery group 100 without a platform region and a second battery group 101 with a platform region, the first battery group 100 and the second battery group 101 being connected in series. The first battery group 100 is a polyanion battery group, and the second battery group 101 is a lithium iron phosphate battery group. The charging rate provided to the first battery group 100 is greater than the charging rate provided to the second battery group 101. The usable capacity of the first battery group 100 under the usage range of the second battery group 101 is equal to the usable capacity of the second battery group 101 under the usage range.

[0096] The battery management system 20 is used to obtain the SOC-OCV curve of the first battery pack 100 in the current voltage range based on the state of charge change data of the first battery pack 100 in the current voltage range; and to determine the current phase change capacity of the first battery pack 100 based on the slope of the SOC-OCV curve. The current voltage range includes either a charging voltage range or a discharging voltage range. At least one alternative phase change capacity matching the current phase change capacity is obtained from the preset phase change capacities corresponding to each battery health state. The preset phase change capacity corresponding to any battery health state is determined based on the correspondence between the open-circuit voltage and the state of charge measured by charging and discharging cycles of a battery sample in a healthy battery state, where the battery sample is of the same type as the battery in the first battery pack 100. Based on the number of charge and discharge cycles corresponding to each alternative phase change capacity, the target phase change capacity with the smallest difference between the corresponding number of charge and discharge cycles and the current number of charge and discharge cycles of the battery pack 10 is obtained from the alternative phase change capacities. The current battery health state of the first battery pack 100 is determined based on the battery health state corresponding to the target phase change capacity. Based on the current battery health status of the first battery pack 100 and the ratio of the battery health status of the first battery pack 100 to that of the second battery pack 101, the current battery health status of the second battery pack 101 is determined. The current battery health status of the battery pack 10 is obtained by finding the minimum value between the current battery health status of the first battery pack 100 and the current battery health status of the second battery pack 101.

[0097] The battery management system 20 is further configured to, when the number of cells in the first battery pack 100 is the same as the number of cells in the battery sample, determine the current remaining capacity of the battery pack 10 based on the state of charge of the battery sample in the battery health state corresponding to the target phase change capacity and the current open-circuit voltage of the first battery pack 100. Alternatively, when the battery sample is a single cell, the system obtains the target open-circuit voltage based on the current open-circuit voltage of the first battery pack 100 and the number of cells in the first battery pack 100; and determines the current remaining capacity of the battery pack 10 based on the state of charge of the battery sample in the battery health state corresponding to the target phase change capacity and the current open-circuit voltage.

[0098] Figure 5 shows a flowchart of a battery pack detection method provided in an embodiment of this application. This battery pack detection method is applied to the battery device in any of the above embodiments, specifically, it can be applied to the battery management system in any of the above embodiments.

[0099] In some embodiments, the battery pack detection method includes:

[0100] S101, determine the current phase change capacity of the first battery pack based on the state of charge change data of the first battery pack in the current voltage range;

[0101] S102, based on the battery health status corresponding to the target phase change capacity that matches the current phase change capacity among the preset phase change capacities, the current battery health status of the battery pack is obtained.

[0102] The current voltage range includes either a charging voltage range or a discharging voltage range;

[0103] The preset phase change capacity corresponding to any of the battery health states is determined based on the correspondence between the open-circuit voltage and the state of charge obtained by charging and discharging a battery sample in the battery health state, wherein the battery sample is of the same type as the battery in the first battery pack.

[0104] By introducing a first battery pack without a plateau region and connecting it in series with a second battery pack that has a plateau region, the current phase change capacity of the first battery pack can be determined based on the change in state of charge (SOC) of the first battery pack within the charging or discharging voltage range. Then, based on the battery health status corresponding to the target SOC that matches the current SOC among the preset SOC, the current battery health status of the battery pack can be obtained. This allows for the estimation of the battery pack's status by observing the changes in SOC and open-circuit voltage of the battery pack without a plateau region within a certain voltage range, without needing to consider the open-circuit voltage changes of the battery pack with a plateau region, thereby improving the accuracy of the battery pack detection results.

[0105] In some embodiments, determining the current phase change capacity of the first battery pack based on the state-of-charge change data of the first battery pack in the current voltage range includes:

[0106] Based on the state of charge change data of the first battery pack in the current voltage range, the SOC-OCV curve of the first battery pack in the current voltage range is obtained; based on the slope of the SOC-OCV curve, the current phase change capacity of the first battery pack is determined.

[0107] In some embodiments, the method further includes:

[0108] From each of the preset phase change capacities, at least one alternative phase change capacity that matches the current phase change capacity is obtained; based on the charge / discharge cycle number corresponding to each alternative phase change capacity, the target phase change capacity with the smallest difference between the charge / discharge cycle number corresponding to each alternative phase change capacity and the current charge / discharge cycle number of the battery pack is obtained from each alternative phase change capacity.

[0109] In some embodiments, obtaining the current battery health status of the battery pack based on the battery health status corresponding to the target phase change capacity that matches the current phase change capacity among the preset phase change capacities includes: determining the current battery health status of the first battery group based on the battery health status corresponding to the target phase change capacity that matches the current phase change capacity among the preset phase change capacities; determining the current battery health status of the second battery group based on the current battery health status of the first battery group and the ratio of the battery health status of the first battery group to that of the second battery group; and obtaining the current battery health status of the battery pack based on the current battery health status of the first battery group and the current battery health status of the second battery group.

[0110] In some embodiments, obtaining the current battery health status of the battery pack based on the current battery health status of the first battery pack and the current battery health status of the second battery pack includes: obtaining the current battery health status of the battery pack based on the minimum value between the current battery health status of the first battery pack and the current battery health status of the second battery pack.

[0111] In some embodiments, the method further includes: if it is determined that the product information of the first battery pack is the same as that of the battery sample, then determining the current remaining capacity of the battery pack based on the state of charge of the battery sample in the battery health state corresponding to the target phase change capacity and the current open circuit voltage of the first battery pack.

[0112] In some embodiments, the battery sample is a single cell sample; the method further includes: obtaining the target open-circuit voltage based on the current open-circuit voltage of the first battery pack and the number of cell strings in the first battery pack; and determining the current remaining capacity of the battery pack based on the state of charge of the battery sample in the battery health state corresponding to the target phase change capacity and the state of charge corresponding to the target open-circuit voltage.

[0113] In some embodiments, the available capacity of the first battery pack during the usage period of the second battery pack is equal to the available capacity of the second battery pack during the usage period.

[0114] Figure 6 shows a schematic diagram of the structure of a battery pack testing device provided in this application. It should be understood that this device corresponds to the method embodiment performed in Figure 1 and is capable of performing the steps involved in the aforementioned method. The specific functions of this device can be found in the description above; to avoid repetition, detailed descriptions are appropriately omitted here. This device includes at least one software functional module that can be stored in a memory or embedded in the device's operating system (OS) in the form of software or firmware. This device can be applied to the battery device in any of the above embodiments; specifically, it can be applied to the battery management system in the battery device. The battery pack testing device includes: a capacity detection module 200, used to determine the current phase change capacity of the first battery pack based on the state of charge change data of the first battery pack under the current voltage range; and a battery pack testing module 201, used to obtain the current battery health state of the battery pack based on the battery health state corresponding to the target phase change capacity that matches the current phase change capacity among each preset phase change capacity; wherein, the current voltage range includes a charging voltage range or a discharging voltage range; the preset phase change capacity corresponding to any of the battery health states is determined based on the correspondence between the open circuit voltage and the state of charge measured by charging and discharging cycles on a battery sample in the battery health state, and the battery sample is of the same type as the battery in the first battery pack.

[0115] In the technical solution of this application embodiment, by introducing a first battery pack without a plateau region and connecting it in series with a second battery pack having a plateau region, the current phase change capacity of the first battery pack can be determined based on the state of charge change data of the first battery pack in the charging voltage range or the discharging voltage range. Then, based on the battery health state corresponding to the target phase change capacity that matches the current phase change capacity among each preset phase change capacity, the current battery health state of the battery pack can be obtained. Thus, the state of the battery pack can be estimated by the changes in the state of charge and open circuit voltage of the battery pack without a plateau region in a certain voltage range, without having to consider the open circuit voltage changes of the battery pack with a plateau region, thereby improving the accuracy of the battery pack detection results.

[0116] According to some embodiments of this application, the capacity detection module 200 is specifically used to: obtain the SOC-OCV curve of the first battery pack in the current voltage range based on the state of charge change data of the first battery pack in the current voltage range; and determine the current phase change capacity of the first battery pack based on the slope of the SOC-OCV curve.

[0117] According to some embodiments of this application, the battery pack detection module 201 is further configured to: obtain at least one alternative phase change capacity that matches the current phase change capacity from each of the preset phase change capacities; and, based on the charge / discharge cycle number corresponding to each of the alternative phase change capacities, obtain the target phase change capacity from each of the alternative phase change capacities whose charge / discharge cycle number has the smallest difference from the current charge / discharge cycle number of the battery pack.

[0118] According to some embodiments of this application, the battery pack detection module 201 is specifically used to: determine the current battery health status of the first battery pack based on the battery health status corresponding to the target phase change capacity that matches the current phase change capacity among each preset phase change capacity; determine the current battery health status of the second battery pack based on the current battery health status of the first battery pack and the ratio of the battery health status of the first battery pack to that of the second battery pack; and obtain the current battery health status of the battery pack based on the current battery health status of the first battery pack and the current battery health status of the second battery pack.

[0119] According to some embodiments of this application, the battery pack detection module 201 is specifically used to: obtain the current battery health state of the battery pack based on the minimum value between the current battery health state of the first battery pack and the current battery health state of the second battery pack.

[0120] According to some embodiments of this application, the battery pack detection module 201 is further configured to: if it is determined that the product information of the first battery pack is the same as that of the battery sample, then determine the current remaining capacity of the battery pack based on the state of charge of the battery sample in the battery health state corresponding to the target phase change capacity and the current open circuit voltage of the first battery pack.

[0121] According to some embodiments of this application, the battery sample is a single cell battery sample; the battery pack detection module 201 is further configured to: obtain the target open circuit voltage based on the current open circuit voltage of the first battery pack and the number of battery strings in the first battery pack; and determine the current remaining capacity of the battery pack based on the state of charge of the battery sample in the battery health state corresponding to the target phase change capacity and the state of charge corresponding to the target open circuit voltage.

[0122] According to some embodiments of this application, as shown in FIG7, this application provides an electronic device 300, including: a processor 301 and a memory 302. The processor 301 and the memory 302 are interconnected and communicate with each other through a communication bus 303 and / or other forms of connection mechanism (not shown). The memory 302 stores a computer program executable by the processor 301. When the computing device is running, the processor 301 executes the computer program to perform a battery pack detection method in any optional implementation.

[0123] This application provides a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the battery pack detection method in any of the aforementioned optional implementations.

[0124] The storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk.

[0125] This application provides a computer program product that, when run on a computer, causes the computer to perform a method in any of the optional implementations.

[0126] This application provides a battery management system, including a processor and a memory storing a computer program, wherein the computer program, when executed by the processor, implements the battery pack detection method in any of the above-mentioned optional implementations.

[0127] This application provides an electrical device that includes a battery device or battery management system as described in the above embodiments. This electrical device includes, but is not limited to, electrical devices used in vehicles, ships, or aircraft.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not 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 or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery device, characterized in that, This includes the battery pack and the battery management system; The battery pack includes a first battery pack without a plateau region and a second battery pack with a plateau region, wherein the first battery pack and the second battery pack are connected in series. The battery management system is used to determine the current phase change capacity of the first battery pack based on the state of charge change data of the first battery pack under the current voltage range, so as to obtain the current battery health status of the battery pack based on the battery health status corresponding to the target phase change capacity that matches the current phase change capacity among the preset phase change capacities. The current voltage range includes either a charging voltage range or a discharging voltage range; The preset phase change capacity corresponding to any of the battery health states is determined based on the correspondence between the open-circuit voltage and the state of charge obtained by charging and discharging a battery sample in the battery health state, wherein the battery sample is of the same type as the battery in the first battery pack.

2. The battery device according to claim 1, characterized in that, The battery management system is specifically used for: Based on the state of charge change data of the first battery pack in the current voltage range, the SOC-OCV curve of the first battery pack in the current voltage range is obtained. The current phase change capacity of the first battery pack is determined based on the slope of the SOC-OCV curve.

3. The battery device according to claim 1 or 2, characterized in that, The battery management system is also used for: From each of the preset phase change capacities, at least one alternative phase change capacity that matches the current phase change capacity is obtained; Based on the number of charge-discharge cycles corresponding to each of the candidate phase change capacities, the target phase change capacity with the smallest difference between the corresponding number of charge-discharge cycles and the current number of charge-discharge cycles of the battery pack is obtained from each of the candidate phase change capacities.

4. The battery device according to claim 1 or 2, characterized in that, The battery management system is specifically used for: Based on the battery health status corresponding to the target phase change capacity that matches the current phase change capacity among the preset phase change capacities, the current battery health status of the first battery pack is determined. The current battery health status of the second battery pack is determined based on the current battery health status of the first battery pack and the ratio of the battery health status of the first battery pack to that of the second battery pack. The current battery health status of the battery pack is obtained based on the current battery health status of the first battery pack and the current battery health status of the second battery pack.

5. The battery device according to claim 4, characterized in that, The battery management system is specifically used for: The current battery health status of the battery pack is obtained by taking the minimum value between the current battery health status of the first battery pack and the current battery health status of the second battery pack.

6. The battery device according to any one of claims 1, 2, or 5, characterized in that, The battery management system is also used for: If it is determined that the product information of the first battery pack is the same as that of the battery sample, then the current remaining capacity of the battery pack is determined based on the state of charge of the battery sample in the battery health state corresponding to the target phase change capacity and the current open circuit voltage of the first battery pack.

7. The battery device according to any one of claims 1, 2, or 5, characterized in that, The battery sample is a sample of a single cell. The battery management system is also used for: The target open-circuit voltage is obtained based on the current open-circuit voltage of the first battery pack and the number of battery strings in the first battery pack; Based on the battery sample under the battery health state corresponding to the target phase change capacity, and the state of charge corresponding to the target open circuit voltage, determine the current remaining capacity of the battery pack.

8. The battery device according to any one of claims 1, 2, or 5, characterized in that, The available capacity of the first battery pack during the usage period of the second battery pack is equal to the available capacity of the second battery pack during the same usage period.

9. The battery device according to any one of claims 1, 2, or 5, characterized in that, The first battery pack is a polyanion battery pack, and the second battery pack is a lithium iron phosphate battery pack.

10. The battery device according to claim 9, characterized in that, The polyanion battery pack includes a sodium-ion battery pack that uses a polyanion compound as the positive electrode material.

11. The battery device according to claim 10, characterized in that, The polyanionic compound includes at least one of sodium vanadium phosphate, sodium titanium phosphate, or sodium iron phosphate.

12. The battery device according to claim 9, characterized in that, The charging rate provided to the first battery pack is greater than the charging rate provided to the second battery pack.

13. A method for detecting a battery pack, characterized in that, Applied to the battery device as described in any one of claims 1-12; The method includes: The current phase change capacity of the first battery pack is determined based on the state of charge change data of the first battery pack in the current voltage range. The current battery health status of the battery pack is obtained based on the battery health status corresponding to the target phase change capacity that matches the current phase change capacity among the preset phase change capacities. The current voltage range includes either a charging voltage range or a discharging voltage range; The preset phase change capacity corresponding to any of the battery health states is determined based on the correspondence between the open-circuit voltage and the state of charge obtained by charging and discharging a battery sample in the battery health state, wherein the battery sample is of the same type as the battery in the first battery pack.

14. A battery pack testing device, characterized in that, Applied to the battery device as described in any one of claims 1-12; The battery pack testing device includes: The capacity detection module is used to determine the current phase change capacity of the first battery pack based on the state of charge change data of the first battery pack in the current voltage range. The battery pack detection module is used to obtain the current battery health status of the battery pack based on the battery health status corresponding to the target phase change capacity that matches the current phase change capacity among the preset phase change capacities. The current voltage range includes either a charging voltage range or a discharging voltage range; The preset phase change capacity corresponding to any of the battery health states is determined based on the correspondence between the open-circuit voltage and the state of charge obtained by charging and discharging a battery sample in the battery health state, wherein the battery sample is of the same type as the battery in the first battery pack.

15. An electronic device comprising a processor and a memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the battery pack detection method of claim 13.

16. A 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 battery pack detection method of claim 13.

17. A battery management system, characterized in that, It includes a processor and a memory storing a computer program, which, when executed by the processor, implements the method of claim 13.

18. An electrical appliance, characterized in that, Includes the battery device as described in any one of claims 1-12, or the battery management system as described in claim 17.

Images