Battery cell temperature prediction method, battery management system, and related devices and apparatuses

Abstract

The application discloses a battery cell temperature prediction method, a battery management system and related devices and equipment. The method comprises the following steps: acquiring a first battery cell temperature of a battery cell and a first ambient temperature of an environment in which the battery cell is located when the BMS is powered off; acquiring a second battery cell temperature of the battery cell and a second ambient temperature of the environment in which the battery cell is located when the BMS is powered on next time; and predicting a temperature change curve of the battery cell in the process from when the BMS is powered off to when the BMS is powered on next time based on the first battery cell temperature, the first ambient temperature, the second battery cell temperature and the second ambient temperature. The temperature change curve of the battery cell in the process from when the BMS is powered off to when the BMS is powered on next time is predicted.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a cell temperature prediction method, a battery management system, a battery device, an electrical device, and an electronic device. Background Technology

[0002] Battery temperature is an important performance indicator of a battery and a crucial parameter for characterizing battery operating conditions and state. Currently, battery temperature calculations typically employ methods such as thermal model-based calculations, direct measurement based on temperature sensors, indirect estimation based on battery thermal characteristics, and prediction based on machine learning.

[0003] Among these, the thermal model-based calculation scheme simulates the heat generation, conduction, and convection processes inside the battery, and calculates the battery's temperature distribution by combining this with the battery's operating status (such as charging and discharging current, power, etc.). The direct measurement scheme based on temperature sensors collects battery temperature data in real time by placing temperature sensors (such as thermistors, thermocouples, etc.) inside or outside the battery. The indirect estimation scheme based on battery thermal characteristics analyzes the battery's thermal characteristic parameters (such as specific heat capacity, thermal conductivity, etc.) and combines this with changes in ambient temperature to indirectly estimate the battery temperature. The prediction scheme based on machine learning establishes a predictive model for battery temperature by collecting historical battery temperature data, charging and discharging data, and environmental data.

[0004] Battery temperature during BMS (Battery Management System) power-off is particularly important for battery life, therefore predicting battery temperature during BMS power-off is an urgent problem to be solved. Summary of the Invention

[0005] This application provides at least one method for predicting cell temperature, a battery management system, a battery device, an electrical device, and an electronic device, enabling cell temperature prediction during BMS power-off.

[0006] This application provides a method for predicting battery cell temperature, including: obtaining a first battery cell temperature and a first ambient temperature of the environment in which the battery cell is located when the BMS is powered off; obtaining a second battery cell temperature and a second ambient temperature of the environment in which the battery cell is located when the BMS is powered on again; and predicting the temperature change curve of the battery cell from the time the BMS is powered off to the time the BMS is powered on again, based on the first battery cell temperature, the first ambient temperature, the second battery cell temperature, and the second ambient temperature.

[0007] In the above scheme, the first cell temperature and the first ambient temperature of the cell's environment are obtained when the BMS is powered off; the second cell temperature and the second ambient temperature of the cell's environment are obtained when the BMS is powered on again; based on the first cell temperature, the first ambient temperature, the second cell temperature, and the second ambient temperature, the temperature change curve of the cell during the process from the BMS power-off to the next BMS power-on is predicted. This allows for the prediction of the cell temperature during the BMS power-off process by collecting actual temperature data during the BMS power-off and next BMS power-on processes, thus providing parameter support for statistical analysis of cell operating conditions and calculation of cell status.

[0008] In some embodiments, obtaining the first cell temperature of the battery cell and the first ambient temperature of the environment where the battery cell is located when the BMS is powered off includes: obtaining the temperature of the battery cell at a first moment within a first preset time period before the BMS is powered off, as the first cell temperature, wherein the first moment is any moment within the first preset time period; and obtaining the temperature of the environment where the battery cell is located at the first moment, as the first ambient temperature.

[0009] In the above scheme, the acquisition time of the first cell temperature and the first ambient temperature is set to the first moment within the first preset time before the BMS is powered off. By acquiring the temperature of the cell adjacent to the BMS before power-off and the temperature of the environment where the cell is located as the first cell temperature and the first ambient temperature, respectively, the true values ​​of the cell temperature and the temperature of the environment where the cell is located at the moment of BMS power-off can be better reflected. This provides real and accurate data support for subsequent prediction of the cell temperature change curve, thereby effectively realizing the prediction of the cell temperature during the BMS power-off process.

[0010] In some embodiments, obtaining the second cell temperature of the battery cell and the second ambient temperature of the environment in which the battery cell is located when the BMS is powered on again includes: obtaining the temperature of the battery cell at a second moment within a second preset time period after the BMS is powered on again, as the second cell temperature, wherein the second moment is any moment within the second preset time period; and obtaining the temperature of the environment in which the battery cell is located at the second moment, as the second ambient temperature.

[0011] In the above scheme, the acquisition time of the second cell temperature and the second ambient temperature is set to the second moment within the second preset time after the BMS is powered on next time. By acquiring the temperature of the cell and the temperature of the environment where the cell is located after the next power-on of the neighboring BMS, respectively, the second cell temperature and the second ambient temperature can better reflect the true values ​​of the cell temperature and the temperature of the environment where the cell is located at the next power-on of the BMS. This provides real and accurate data support for the subsequent prediction of the cell temperature change curve, thereby effectively realizing the prediction of the cell temperature during the BMS power-off process.

[0012] In some embodiments, predicting the temperature change curve of the battery cell from the time the BMS is powered off to the time the BMS is powered on again, based on the first cell temperature, the first ambient temperature, the second cell temperature, and the second ambient temperature, includes: obtaining a first time duration during which the temperature of the battery cell changes from the first cell temperature to the first ambient temperature; and, in response to the first time duration being greater than or equal to the total power-off time from the time the BMS is powered off to the time the BMS is powered on again, obtaining the temperature change curve of the battery cell as a first target temperature change curve, wherein the first target temperature change curve represents the change curve from the first cell temperature to the second cell temperature within the total power-off time.

[0013] In the above scheme, by obtaining the first time taken for the first cell temperature to rise to the first ambient temperature, and comparing the first time with the total power-down time, a first target temperature change curve with the first time being greater than or equal to the total power-down time is obtained, thereby predicting the cell temperature during the BMS power-down process and providing parameter support for statistical analysis of cell operating conditions and cell status calculation.

[0014] In some embodiments, in the first target temperature change curve, the rate of change from the first cell temperature to the second cell temperature is the ratio of the difference between the second cell temperature and the first cell temperature to the total power-down time.

[0015] In the above scheme, the first target temperature change curve is predicted by plotting a curve including the rate of change from the temperature of the first cell to the temperature of the second cell, thereby realizing the prediction of the cell temperature during the BMS power-down process and providing parameter support for statistical cell operating conditions and cell state calculation.

[0016] In some embodiments, predicting the temperature change curve of the battery cell from power-off to the next power-on of the BMS based on the first cell temperature, the first ambient temperature, the second cell temperature, and the second ambient temperature includes: obtaining a first duration for the temperature of the battery cell to change from the first cell temperature to the first ambient temperature; in response to the first duration being less than the total power-off duration from power-off to the next power-on of the BMS, obtaining a second duration for the temperature of the battery cell to change from the first ambient temperature to the second cell temperature; in response to the sum of the first duration and the second duration being greater than the total power-off duration, obtaining the temperature change curve of the battery cell as a second target temperature change curve, wherein the second target temperature change curve represents the change curve from the first cell temperature to the second cell temperature within the total power-off duration, and includes a first temperature curve segment and a second temperature curve segment, the first temperature curve segment representing the change from the first cell temperature to the first ambient temperature within the first duration, and the second temperature curve segment representing the change from the first ambient temperature to the second cell temperature within the difference between the total power-off duration and the first duration.

[0017] In the above scheme, by obtaining the first time taken for the temperature of the first cell to rise to the first ambient temperature, and comparing the first time with the total power-down time, a second target temperature change curve is obtained in which the sum of the first time and the second time is greater than the total power-down time. This enables the prediction of the cell temperature during the power-down process of the BMS, and provides parameter support for statistical analysis of cell operating conditions and calculation of cell status.

[0018] In some embodiments, in the first temperature curve segment, the rate of change from the first cell temperature to the first ambient temperature is the ratio of the difference between the first ambient temperature and the first cell temperature to the first duration; in the second temperature curve segment, the rate of change from the first ambient temperature to the second cell temperature is the ratio of the difference between the second cell temperature and the first ambient temperature to the difference between the total power-down time and the first duration.

[0019] In the above scheme, by plotting a first temperature curve segment including the rate of change from the first cell temperature to the first ambient temperature and a second temperature curve segment including the rate of change from the first ambient temperature to the second cell temperature, the cell temperature during the BMS power-down process can be predicted, providing parameter support for statistical cell operating conditions and cell state calculation.

[0020] In some embodiments, predicting the temperature change curve of the battery cell from the time the BMS is powered off to the time the BMS is powered on again, based on the first cell temperature, the first ambient temperature, the second cell temperature, and the second ambient temperature, includes: obtaining a first duration for the temperature of the battery cell to change from the first cell temperature to the first ambient temperature; in response to the first duration being less than the total power-off time from the time the BMS is powered off to the time the BMS is powered on again, obtaining a second duration for the temperature of the battery cell to change from the first ambient temperature to the second cell temperature; and in response to the sum of the first duration and the second duration being less than or equal to the total power-off time, obtaining the temperature change curve of the battery cell as a third target temperature change curve, wherein the third target temperature change curve represents the change curve from the first cell temperature to the second cell temperature within the total power-off time.

[0021] In the above scheme, by obtaining the first time taken for the cell temperature to change to the first ambient temperature, and comparing the first time with the total power-down time, and then, in response to the first time being less than the total power-down time, the second time for the cell temperature to change from the first ambient temperature to the second cell temperature is calculated. Thus, in response to the sum of the first time and the second time being less than or equal to the total power-down time, the difference between the total power-down time and the sum of the first and second times is obtained after the cell temperature changes to the first ambient temperature. The second time is then used to change the cell temperature from the first ambient temperature to the second cell temperature, thereby obtaining a third target temperature change curve. This provides parameter support for statistical analysis of cell operating conditions and cell state calculation, thus effectively enabling the prediction of cell temperature during the BMS power-down process.

[0022] In some embodiments, the third target temperature change curve includes a third temperature curve segment, a fourth temperature curve segment, and a fifth temperature curve segment connected in sequence. The third temperature curve segment represents the change from the first cell temperature to the first ambient temperature within the first duration. The fourth temperature curve segment represents the maintenance at the first ambient temperature within the difference between the total power-down duration and the sum of the first duration and the second duration. The fifth temperature curve segment represents the change from the first ambient temperature to the second cell temperature within the second duration.

[0023] In the above scheme, the third target temperature change curve includes a third temperature curve segment, a fourth temperature curve segment, and a fifth temperature curve segment connected in sequence, which represent the different temperature changes of the third target temperature change curve when powered off. This provides parameter support for statistical analysis of cell operating conditions and cell status calculation, thereby effectively enabling the prediction of cell temperature during the BMS power-off process.

[0024] In some embodiments, in the third temperature curve segment, the rate of change from the first cell temperature to the first ambient temperature is the ratio of the difference between the first ambient temperature and the first cell temperature to the first duration; in the fourth temperature curve segment, the rate of change of the first ambient temperature is kept at zero; in the fifth temperature curve segment, the rate of change from the first ambient temperature to the second cell temperature is the ratio of the difference between the second cell temperature and the first ambient temperature to the second duration.

[0025] In the above scheme, by plotting a third temperature curve segment including the rate of change from the first cell temperature to the first ambient temperature, a fourth temperature curve segment maintaining the rate of change at the first ambient temperature, and a fifth temperature curve segment representing the rate of change from the first ambient temperature to the second cell temperature, the temperature change information of the cell can be observed more directly. This provides parameter support for statistical analysis of cell operating conditions and calculation of cell status, thereby effectively enabling the prediction of cell temperature during the BMS power-down process.

[0026] In some embodiments, the BMS is powered off after a preset time following power-on.

[0027] In the above scheme, after the BMS is powered on for a preset time, the BMS is powered off and the first cell temperature and the first ambient temperature are collected when the BMS is powered off, providing data support for subsequent temperature prediction.

[0028] In some embodiments, the BMS is powered on again for the preset time in response to the total power-down time from power-down to the next power-on of the BMS reaching a preset value.

[0029] In the above scheme, by setting a preset value for the total power-down time from BMS power-down to the next power-up, the power-down time of BMS is maintained at the preset time during the next power-up after reaching the preset value. The second cell temperature and the second ambient temperature of the battery cell are collected during the next power-up of BMS to provide data support for subsequent temperature prediction.

[0030] This application provides a battery management system for performing the above-described cell temperature prediction method.

[0031] This application provides a battery device, including a battery cell and the aforementioned battery management system, wherein the battery cell is connected to the battery management system.

[0032] This application provides an electrical device, including the aforementioned battery device.

[0033] This application provides a battery device, including a memory and a processor, wherein the processor is used to execute program instructions stored in the memory to implement the above-described cell temperature prediction method.

[0034] In the above scheme, the first cell temperature and the first ambient temperature of the cell's environment are obtained when the BMS is powered off; the second cell temperature and the second ambient temperature of the cell's environment are obtained when the BMS is powered on again; based on the first cell temperature, the first ambient temperature, the second cell temperature, and the second ambient temperature, the temperature change curve of the cell during the process from the BMS power-off to the next BMS power-on is predicted. This allows for the prediction of the cell temperature during the BMS power-off process by collecting actual temperature data during the BMS power-off and next BMS power-on processes, thus providing parameter support for statistical analysis of cell operating conditions and calculation of cell status.

[0035] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this application. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with this application and, together with the specification, serve to explain the technical solutions of this application.

[0037] Figure 1 These are schematic diagrams of the BMS and battery cell structures of some embodiments of this application;

[0038] Figure 2 This is a flowchart illustrating the cell temperature prediction method of some embodiments of this application. Figure 1 ;

[0039] Figure 3 This is a schematic diagram of the first target temperature change curve of some embodiments of this application;

[0040] Figure 4 This is a schematic diagram of the second target temperature change curves in some embodiments of this application;

[0041] Figure 5 This is a schematic diagram of the third target temperature change curve in some embodiments of this application;

[0042] Figure 6 This is a flowchart illustrating the cell temperature prediction method of some embodiments of this application. Figure 2 ;

[0043] Figure 7 This is a schematic diagram of BMS periodic sampling in some embodiments of this application;

[0044] Figure 8 This is a flowchart illustrating the cell temperature prediction method of some embodiments of this application. Figure 3 ;

[0045] Figure 9This is a schematic diagram of the structure of a cell temperature prediction system according to some embodiments of this application;

[0046] Figure 10 This is a schematic diagram of the structure of a battery device according to some embodiments of this application;

[0047] Figure 11 These are schematic diagrams of the structure of electrical devices according to some embodiments of this application;

[0048] Figure 12 These are schematic diagrams of the structure of electronic devices according to some embodiments of this application;

[0049] Figure 13 This is a schematic diagram of the framework of a non-volatile computer-readable storage medium according to some embodiments of this application. Detailed Implementation

[0050] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0051] In the following description, specific details such as particular system architectures, interfaces, and technologies are presented for illustrative purposes rather than for limiting purposes, in order to provide a thorough understanding of this application.

[0052] In this document, 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 " / " generally indicates that the preceding and following related objects have an "or" relationship. Furthermore, "many" in this document means two or more. Moreover, the term "at least one" in this document means any combination of at least two of any one or more of a plurality of objects. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0053] As mentioned above, predicting battery temperature during BMS power-off is a critical problem that urgently needs to be solved, as battery temperature during BMS power-off is particularly important for battery life. If a thermal model-based calculation scheme is used to predict battery temperature during BMS power-off, the model's accuracy will decrease because the battery is in a static state and the input parameters (such as charging and discharging current) are missing. Furthermore, the computational complexity of thermal models is high, making real-time calculation difficult. If a direct measurement scheme based on temperature sensors is used to predict battery temperature during BMS power-off, the temperature sensors will not function properly after the BMS is powered off, making real-time monitoring of battery temperature impossible. If an indirect estimation scheme based on battery thermal characteristics is used to predict battery temperature during BMS power-off, the existing estimation methods cannot accurately adapt to changes in battery thermal characteristics due to aging and varying usage conditions. If a machine learning-based prediction scheme is used to predict battery temperature during BMS power-off, it requires a large amount of historical data and has limited model generalization ability.

[0054] Therefore, this solution obtains the first cell temperature and the first ambient temperature of the cell when the BMS is powered off; and the second cell temperature and the second ambient temperature of the cell when the BMS is powered on again. Based on the first cell temperature, the first ambient temperature, the second cell temperature, and the second ambient temperature, the solution predicts the temperature change curve of the cell from the BMS power-off to the next BMS power-on. By collecting actual temperature data during the BMS power-off and next BMS power-on processes, the solution can predict the cell temperature during the BMS power-off process, thus providing parameter support for statistical analysis of cell operating conditions and cell status calculations.

[0055] The following explains the relevant terms used in this application: BMS power-down refers to the process by which the BMS, according to preset shutdown logic or external shutdown commands, first disconnects the electrical connection between the battery pack and the external load / charger, then completes data storage and peripheral power-off operations, and finally puts its core module into a low-power sleep state. BMS power-on refers to the process by which the BMS, according to preset startup logic or external wake-up commands, sequentially completes hardware initialization, software self-test, battery status parameter acquisition and diagnosis, establishes a valid electrical connection between the battery pack and the external load / charger, and enters normal operating mode. A battery cell can be a single battery cell, which is a basic unit capable of converting chemical energy into electrical energy. It can be used to manufacture battery modules or battery packs to supply power to electrical devices. A single battery cell can be a rechargeable battery, which is a battery cell that can be recharged after discharge to reactivate its active materials and continue to be used.

[0056] Please see Figure 1 and Figure 2 , Figure 1 These are schematic diagrams of the BMS and battery cell structures according to some embodiments of this application. Figure 2 This is a flowchart illustrating the cell temperature prediction method of some embodiments of this application. Figure 1 The cell temperature prediction method includes the following steps: Step S21: Obtain the first cell temperature and the first ambient temperature of the cell's environment when the BMS is powered off. Step S22: Obtain the second cell temperature and the second ambient temperature of the cell's environment when the BMS is powered on again. Step S23: Based on the first cell temperature, the first ambient temperature, the second cell temperature, and the second ambient temperature, predict the cell temperature change curve from when the BMS is powered off to when the BMS is powered on again.

[0057] like Figure 1 As shown, BMS 11 is connected to battery pack 12, and also to the battery cells 13 and NTC (Negative Temperature Coefficient) thermistors 14 in battery pack 12. The number of battery cells 13 and NTC thermistors 14 in battery pack 12 is not specified. Figure 1This diagram illustrates one connection method or positional relationship between BMS 11, battery pack 12, battery cell 13, and NTC thermistor 14. The connection between BMS 11 and battery pack 12 / cell 13 can be illustrated as follows: In one example, BMS 11 is connected to the total positive / total negative output terminals of battery pack 12 via a high-voltage harness to monitor the total voltage and current of battery pack 12. It is also connected to the two poles of battery cell 13 via a balancing harness to acquire the voltage of battery cell 13 and perform active balancing control. Similarly, the connection between BMS 11 and NTC thermistor 14 can be illustrated as follows: In one example, the two pins of NTC thermistor 14 are connected to BMS 11 via a sampling harness, forming a temperature measurement loop. BMS 11 acquires the voltage signal across NTC thermistor 14, and by combining this signal with the resistance value and temperature calibration curve of NTC thermistor 14, the temperature of NTC thermistor 14 can be obtained, thereby determining the temperature of the corresponding battery cell 13. The positional relationship between the battery cell 13 and the NTC thermistor 14 can be any of the following examples. In one example, the NTC thermistor 14 can be tightly contacted to the surface of the battery cell 13 by means of thermally conductive adhesive or clip-on fixing, or the NTC thermistor 14 can be arranged at the temperature measuring point in the gap between the battery cells (not shown in the figure), or the NTC thermistor 14 can be integrated into the tab or bracket of the battery cell 13 (not shown in the figure). The first battery cell temperature can be the temperature of the surface of the battery cell 13 when the BMS 11 is powered off, which can be directly measured by the NTC thermistor 14 placed on the surface of the battery cell 13. The first ambient temperature can be the temperature of the environment in which the battery cell 13 is located when the BMS 11 is powered off, such as the temperature above, below, or other different locations of the battery cell 13. That is to say, the first ambient temperature can be directly measured by the NTC thermistor 14 placed near the battery cell 13. The second cell temperature can be the surface temperature of cell 13 when BMS 11 is powered on again, and can be directly measured by the NTC thermistor 14 placed on the surface of cell 13. The second ambient temperature can be the temperature of the environment in which cell 13 is located when BMS 11 is powered on again. The first and second cell temperatures can be directly measured by the same NTC thermistor 14, and the first and second ambient temperatures can also be directly measured by the same NTC thermistor 14. The process from BMS 11 powering off to its next power-on can be referred to as the BMS 11 power-off process. The temperature change curve can represent the temperature change of cell 13 from BMS 11 powering off to its next power-on.Based on the first cell temperature, the first ambient temperature, the second cell temperature, and the second ambient temperature, predict the temperature change curve of cell 13 during the process from the power-off of BMS 11 to the next power-on of BMS 11. For example, the temperature change curve of cell 13 from the first cell temperature to the first ambient temperature.

[0058] In the above scheme, by acquiring the first cell temperature of the battery cell 13 and the first ambient temperature of the environment where the battery cell 13 is located when the BMS 11 is powered off; and acquiring the second cell temperature of the battery cell 13 and the second ambient temperature of the environment where the battery cell 13 is located when the BMS 11 is powered on again; based on the first cell temperature, the first ambient temperature, the second cell temperature, and the second ambient temperature, the temperature change curve of the battery cell 13 during the process from the power-off of the BMS 11 to the next power-on of the BMS 11 is predicted, thereby enabling the prediction of the temperature of the battery cell 13 during the power-off process of the BMS 11 by collecting the actual temperature data during the power-off and next power-on process of the BMS 11, thus providing parameter support for statistical analysis of battery cell operating conditions and calculation of battery cell status.

[0059] In some embodiments, obtaining the first cell temperature of the battery cell 13 and the first ambient temperature of the environment where the battery cell 13 is located when the BMS 11 is powered off includes: obtaining the temperature of the battery cell 13 at a first moment within a first preset time period before the BMS 11 is powered off, as the first cell temperature, wherein the first moment is any moment within the first preset time period; and obtaining the temperature of the environment where the battery cell 13 is located at the first moment, as the first ambient temperature.

[0060] The first preset duration can be a period of time from before BMS 11 is powered off to when BMS 11 is powered off. For example, 1 second before BMS 11 is powered off, i.e., the first preset duration can be 1 second. The first moment can be any moment within the first preset duration. For example, if the first preset duration is 1 second, the first moment can be any moment within 1 second. The temperature of cell 13 at the first moment within the first preset duration before BMS 11 is powered off is obtained as the first cell temperature. Taking a first preset duration of 1 second as an example, the temperature of cell 13 is obtained 0.1 seconds before BMS 11 is powered off, or 0.5 seconds before BMS 11 is powered off, or 0.9 seconds before BMS 11 is powered off. The closer the first moment is to the moment BMS 11 is powered off, the closer the temperature of cell 13 measured at this time is to the temperature of cell 13 when BMS 11 is powered off. Similarly, the temperature of the environment in which cell 13 is located at the first moment is obtained as the first ambient temperature. That is, when obtaining the cell temperature at the first moment within the first preset time period before BMS 11 is powered off, the temperature of the environment in which cell 13 is located is also obtained as the first ambient temperature. For example, in an example where the first preset time period is 1 second and the first moment is any moment within 1 second, when obtaining the temperature of cell 13 0.1 seconds before BMS 11 is powered off, the temperature of the environment in which cell 13 is located is obtained as the first ambient temperature; or, when obtaining the temperature of cell 13 0.5 seconds before BMS 11 is powered off, the temperature of the environment in which cell 13 is located is obtained as the first ambient temperature; or, when obtaining the temperature of cell 13 0.9 seconds before BMS 11 is powered off, the temperature of the environment in which cell 13 is located is obtained as the first ambient temperature. The closer the first moment is to the moment when BMS 11 is powered off, the closer the measured ambient temperature of cell 13 is to the ambient temperature at the time BMS 11 is powered off. The first preset duration is used to determine the moment when BMS 11 is powered off, thus relating it to the first cell temperature and the first ambient temperature at the time BMS 11 is powered off. For example, the first cell temperature and the first ambient temperature of cell 13 measured 1 second before BMS 11 is powered off are more reflective of the temperature of cell 13 and the temperature of the environment in which cell 13 is located at the moment BMS 11 is powered off, compared to the first cell temperature and the first ambient temperature of cell 13 measured 10 seconds before BMS 11 is powered off. The value of the first preset duration can be set to a value close to the moment BMS 11 is powered off, such as 0.5 seconds or 1 second.

[0061] In the above scheme, the acquisition time of the first cell temperature and the first ambient temperature is set to the first moment within the first preset time before the BMS 11 is powered off. By acquiring the temperature of the cell 13 adjacent to the BMS 11 before it is powered off and the temperature of the environment where the cell 13 is located, respectively, the first cell temperature and the first ambient temperature can be more accurately reflected. This provides real and accurate data support for the subsequent prediction of the temperature change curve of the cell 13, thereby effectively predicting the temperature of the cell 13 during the power-off process of the BMS 11.

[0062] In some embodiments, obtaining the second cell temperature of the battery cell 13 and the second ambient temperature of the environment where the battery cell 13 is located when the BMS 11 is powered on for the next time includes: obtaining the temperature of the battery cell 13 at a second moment within a second preset time period after the BMS 11 is powered on for the next time, as the second cell temperature, wherein the second moment is any moment within the second preset time period; and obtaining the temperature of the environment where the battery cell 13 is located at the second moment, as the second ambient temperature.

[0063] The second preset duration can be a period of time after the BMS 11 is powered on again, for example, 1 second after the BMS 11 is powered on again. That is, the second preset duration can be 1 second. The second moment can be any moment within the second preset duration; for example, if the second preset duration is 1 second, the second moment can be any moment within that 1 second. The temperature of cell 13 at the second moment within the second preset duration after the BMS 11 is powered on again is obtained as the second cell temperature. Taking a second preset duration of 1 second as an example, the temperature of cell 13 is obtained 0.1 seconds after the BMS 11 is powered on again, or 0.5 seconds after the BMS 11 is powered on again, or 0.9 seconds after the BMS 11 is powered on again. The closer the second moment is to the moment the BMS 11 is powered off, the closer the measured temperature of cell 13 will be to the temperature of cell 13 at the time of the BMS 11's next power-on. Similarly, the temperature of the environment in which cell 13 is located at the second moment is obtained as the second ambient temperature. That is, when obtaining the cell temperature at the second moment within the second preset time period after the next power-on of BMS 11, the temperature of the environment in which cell 13 is located is also obtained as the second ambient temperature. For example, in an example where the second preset time period is 1 second and the second moment is any moment within 1 second, when obtaining the temperature of cell 13 0.1 seconds after the next power-on of BMS 11, the temperature of the environment in which cell 13 is located is also obtained as the second ambient temperature; or, when obtaining the temperature of cell 13 0.5 seconds after the next power-on of BMS 11, the temperature of the environment in which cell 13 is located is also obtained as the second ambient temperature; or, when obtaining the temperature of cell 13 0.9 seconds after the next power-on of BMS 11, the temperature of the environment in which cell 13 is located is also obtained as the second ambient temperature. Here, the second preset time period is used to determine the time of the next power-on of BMS 11, and thus relates it to the second cell temperature and the second ambient temperature at the time of the next power-on of BMS 11. For example, the second cell temperature and second ambient temperature of cell 13 measured 1 second after the next power-on of BMS 11 are more reflective of the temperature of cell 13 and the temperature of its environment at the moment of the next power-on of BMS 11 than the second cell temperature and second ambient temperature measured 10 seconds after the next power-on of BMS 11. The value of the second preset duration is usually set to a value close to the moment of the next power-on of BMS 11, such as 0.5 seconds or 1 second. The termination point in the process from the power-off of BMS 11 to the next power-on of BMS 11 is the second moment within the second preset duration after the next power-on of BMS 11.

[0064] In the above scheme, the acquisition time of the second cell temperature and the second ambient temperature is set to the second moment within the second preset time after the BMS 11 is powered on next time. By acquiring the temperature of the cell 13 and the temperature of the environment where the cell 13 is located after the next power-on of the adjacent BMS 11, respectively, the second cell temperature and the second ambient temperature can better reflect the true values ​​of the temperature of the cell 13 and the temperature of the environment where the cell 13 is located at the next power-on of the BMS 11. This provides real and accurate data support for the subsequent prediction of the temperature change curve of the cell 13, thereby effectively realizing the prediction of the temperature of the cell 13 during the power-off process of the BMS 11.

[0065] In some embodiments, based on a first cell temperature, a first ambient temperature, a second cell temperature, and a second ambient temperature, predicting the temperature change curve of cell 13 during the period from power-down of BMS 11 to the next power-on of BMS 11 includes: acquiring a first time duration during which the temperature of cell 13 changes from the first cell temperature to the first ambient temperature; and in response to the first time duration being greater than or equal to the total power-down time from power-down of BMS 11 to the next power-on of BMS 11, acquiring the temperature change curve of cell 13 as a first target temperature change curve, wherein the first target temperature change curve represents the change curve from the first cell temperature to the second cell temperature within the total power-down time.

[0066] Taking the case where the temperature of the first battery cell is higher than the temperature of the first ambient temperature as an example, the curve of the first target temperature change is as follows: Figure 3 As shown, the horizontal axis represents time t, and the vertical axis represents temperature T. The first cell temperature of cell 13, The second cell temperature of cell 13. Total power-off time The time can be obtained through the RTC (Real-Time Clock) in BMS 11. For example, when BMS 11 powers off, the RTC time is read and recorded. When BMS 11 powers on again, the RTC time is read and recorded again. The difference between the two read times is then calculated to obtain the time. The first duration can be used express, Based on and Obtain, for example, through and The ratio of the temperature difference to the average rate of temperature decrease is obtained. ,in The average rate of change over a time period can be based on and The result is that the first power-off duration is greater than the total power-off duration from the power-down of BMS 11 to the next power-on of BMS 11, i.e. > In other words, before the temperature of cell 13 has changed from the first cell temperature to the first ambient temperature, BMS 11 has already performed the next power-on. The obtained first target temperature change curve is the temperature of cell 13 starting from the first cell temperature and... Temperature change curve over a time period. The first duration equals the total power-off time from when BMS 11 is powered off to when BMS 11 is powered on again, i.e. = In other words, the first target temperature change curve obtained is the temperature change curve of cell 13 from the first cell temperature to the first ambient temperature, at which time the second cell temperature is equal to the first ambient temperature.

[0067] In the above scheme, by obtaining the first time taken for the first cell temperature to rise to the first ambient temperature, and comparing the first time with the total power-down time, a first target temperature change curve with the first time being greater than or equal to the total power-down time is obtained, thereby predicting the cell temperature during the power-down process of BMS 11, and providing parameter support for statistical analysis of cell operating conditions and cell status calculation.

[0068] In some embodiments, in the first target temperature change curve, the rate of change from the first cell temperature to the second cell temperature is the ratio of the difference between the second cell temperature and the first cell temperature to the total power-down time.

[0069] Taking a first cell temperature higher than the first ambient temperature as an example, the rate of change from the first cell temperature to the second cell temperature can be obtained by subtracting the first cell temperature from the second cell temperature and then dividing the result by the total power-down time. The rate of change can be the average rate of change, for example... Figure 3 middle The average rate of change is calculated from the slopes at all points within the time period. It should be noted that a negative slope on this curve indicates that the temperature is decreasing over time.

[0070] In the above scheme, the first target temperature change curve is predicted by plotting a curve including the rate of change from the temperature of the first cell to the temperature of the second cell, thereby realizing the prediction of the cell temperature during the power-down process of BMS 11, and providing parameter support for statistical cell operating conditions and cell state calculation.

[0071] In some embodiments, based on a first cell temperature, a first ambient temperature, a second cell temperature, and a second ambient temperature, predicting the temperature change curve of cell 13 during the process from power-down of BMS 11 to the next power-up of BMS 11 includes: acquiring a first duration for the temperature of cell 13 to change from the first cell temperature to the first ambient temperature; in response to the first duration being less than the total power-down duration from power-down of BMS 11 to the next power-up of BMS 11, acquiring a second duration for the temperature of cell 13 to change from the first ambient temperature to the second cell temperature; in response to the sum of the first duration and the second duration being greater than the total power-down duration, acquiring the temperature change curve of cell 13 as a second target temperature change curve, wherein the second temperature change curve represents the change curve from the first cell temperature to the second cell temperature within the total power-down duration, and includes a first temperature curve segment and a second temperature curve segment, the first temperature curve segment representing the change from the first cell temperature to the first ambient temperature within the first duration, and the second temperature curve segment representing the change from the first ambient temperature to the second cell temperature within the difference between the total power-down duration and the first duration.

[0072] Taking the example where the temperature of the first battery cell is higher than the first ambient temperature, and the first ambient temperature is higher than the temperature of the second battery cell, such as... Figure 4 As shown, the horizontal axis represents time t, and the vertical axis represents temperature T, with the first duration... Total power-off time The method for obtaining this is detailed in the above embodiments. Wherein, the first duration is less than the total power-off duration, i.e. < In other words, after the temperature of cell 13 changes from the first cell temperature to the first ambient temperature within the first time period, BMS 11 still has not performed the next power-on. The second time period can be the time it takes for the temperature of cell 13 to change from the first ambient temperature to the second cell temperature after reaching the first ambient temperature, such as... Figure 4 , For the second duration, Based on and Obtain, for example, through and The ratio of the temperature difference to the average rate of temperature decrease is obtained. ,in The average rate of change over a time period can be based on and We have obtained the result. The sum of the first and second durations is greater than the total power-off duration, i.e. > In other words, after the temperature of cell 13 changes from the first cell temperature to the first ambient temperature within the first duration, it changes from the first ambient temperature to the second cell temperature within the difference between the total power-down time and the first duration. At this time, the obtained second target temperature change curve includes a first temperature curve segment and a second temperature curve segment connected in sequence. The first temperature curve segment is as follows: Figure 4 middle The curve segment within the time period is shown, and the second temperature curve segment is shown as follows. Figure 4 The Middle The solid line segment is shown as the curve segment within the time period. This refers to the actual time it takes for the temperature of cell 13 to change from the first ambient temperature to the second cell temperature. = - The temperature change trend of cell 13 corresponding to the second temperature curve segment may differ from the temperature change trend corresponding to the first temperature curve segment, such as... Figure 4 The temperature change trend of cell 13 in the second temperature curve segment shown is different from the temperature change trend of cell 13 in the first temperature curve segment.

[0073] In the above scheme, by obtaining the first time taken for the temperature of the first cell to rise to the first ambient temperature, and comparing the first time with the total power-down time, a second target temperature change curve is obtained in which the sum of the first time and the second time is greater than the total power-down time. This enables the prediction of the cell temperature during the power-down process of BMS 11, providing parameter support for statistical analysis of cell operating conditions and cell status calculation.

[0074] In some embodiments, in the first temperature curve segment, the rate of change from the first cell temperature to the first ambient temperature is the ratio of the difference between the first ambient temperature and the first cell temperature to the first duration; in the second temperature curve segment, the rate of change from the first ambient temperature to the second cell temperature is the ratio of the difference between the second cell temperature and the first ambient temperature to the difference between the total power-down time and the first duration.

[0075] Taking a scenario where the temperature of the first battery cell is higher than the first ambient temperature, and the first ambient temperature is higher than the temperature of the second battery cell, the rate of change from the temperature of the first battery cell to the temperature of the second battery cell can be obtained by subtracting the temperature of the first battery cell from the temperature of the second battery cell, and then dividing this result by the total power-down time. The rate of change can be the average rate of change, for example... Figure 4 middle The average rate of change is calculated from the slopes corresponding to all moments within the time period. The rate of change from the first ambient temperature to the second cell temperature can be obtained by subtracting the first ambient temperature from the second cell temperature and dividing the result by the difference between the total power-down time and the first power-down time. This rate of change can be the average rate of change, for example... Figure 4 middle The average rate of change is calculated from the slopes at all points within the time period. The different trends in the first and second temperature curve segments are characterized by different rates of temperature decrease. It should be noted that a negative slope on this curve indicates a decreasing temperature over time.

[0076] In the above scheme, by plotting a first temperature curve segment including the rate of change from the first cell temperature to the first ambient temperature and a second temperature curve segment including the rate of change from the first ambient temperature to the second cell temperature, the cell temperature during the power-down process of BMS 11 can be predicted, providing parameter support for statistical cell operating conditions and cell state calculation.

[0077] In some embodiments, based on a first cell temperature, a first ambient temperature, a second cell temperature, and a second ambient temperature, predicting the temperature change curve of cell 13 during the process from power-down of BMS 11 to the next power-up of BMS 11 includes: acquiring a first duration for the temperature of cell 13 to change from the first cell temperature to the first ambient temperature; in response to the first duration being less than the total power-down time from power-down of BMS 11 to the next power-up of BMS 11, acquiring a second duration for the temperature of cell 13 to change from the first ambient temperature to the second cell temperature; and in response to the sum of the first duration and the second duration being less than or equal to the total power-down time, acquiring the temperature change curve of cell 13 as a third target temperature change curve, wherein the third temperature change curve represents the change curve from the first cell temperature to the second cell temperature within the total power-down time.

[0078] Taking the example where the temperature of the first battery cell is higher than the first ambient temperature, and the first ambient temperature is higher than the temperature of the second battery cell, such as... Figure 5 As shown, the horizontal axis represents time t, and the vertical axis represents temperature T, with the first duration... First duration and total power-off time See the above embodiment for details. The first duration is less than the total power-off duration, i.e. < In other words, after the temperature of cell 13 changes from the first cell temperature to the first ambient temperature within the first time period, BMS 11 still has not performed another power-on. The sum of the first time period and the second time period is less than the total power-off time. < In other words, the total power-down time of the battery cell 13 includes another time period in addition to the first time period and the second time period. After the temperature of the battery cell 13 changes from the first battery cell temperature to the first ambient temperature within the first time period, it remains for a period of time, and then changes from the first ambient temperature to the second battery cell temperature within the second time period, thus obtaining the third target temperature change curve of the battery cell 13.

[0079] In the above scheme, by obtaining the first time taken for the cell temperature to change to the first ambient temperature, and comparing the first time with the total power-down time, and then, in response to the first time being less than the total power-down time, the second time for the cell 13 to change from the first ambient temperature to the second cell temperature is calculated. Thus, in response to the sum of the first time and the second time being less than or equal to the total power-down time, the difference between the total power-down time and the sum of the first time and the second time is obtained after the first cell temperature changes to the first ambient temperature. Then, the cell temperature changes from the first ambient temperature to the second cell temperature in the second time, thereby obtaining the third target temperature change curve. This provides parameter support for statistical analysis of cell operating conditions and cell status calculation, thereby effectively predicting the temperature of the cell 13 during the power-down process of BMS 11.

[0080] In some embodiments, the third target temperature change curve includes a third temperature curve segment, a fourth temperature curve segment, and a fifth temperature curve segment connected in sequence. The third temperature curve segment represents the change from the first cell temperature to the first ambient temperature within the first duration. The fourth temperature curve segment represents the maintenance at the first ambient temperature within the difference between the total power-down duration and the sum of the first duration and the second duration. The fifth temperature curve segment represents the change from the first ambient temperature to the second cell temperature within the second duration.

[0081] Continuing with the example where the temperature of the first battery cell is higher than the first ambient temperature, and the first ambient temperature is higher than the temperature of the second battery cell, please refer to [the relevant documentation]. Figure 5 The third target temperature change curve of cell 13 includes a third temperature curve segment, a fourth temperature curve segment, and a fifth temperature curve segment connected in sequence. The third temperature curve segment is as follows: Figure 5 middle The curve segments within the time period are shown, and the fourth temperature curve segment is shown as follows. Figure 5 middle The curve segments within the time period are shown. The temperature of cell 13 is maintained at the first ambient temperature for a certain period of time, and the fifth temperature change curve is as follows: Figure 5 middle The curve segment within the time period is shown. The sum of the first duration and the second duration equals the total power-off duration, i.e. = In other words, after the temperature of cell 13 changes from the first cell temperature to the first ambient temperature within the first time period, and then changes from the first ambient temperature to the second cell temperature within the second time period, the obtained third target temperature change curve includes a third temperature curve segment, a fourth temperature curve segment, and a fifth temperature curve segment connected in sequence. The third temperature curve segment is as follows: Figure 5 middle The curve segments within the time period are shown, and the fourth temperature curve segment is shown as follows. Figure 5middle The curve segments within the time period are shown. For the time period during which the temperature of cell 13 is maintained at the first ambient temperature, the fifth temperature curve segment is as follows: Figure 5 middle The curve segments within the time period are shown. The temperature change trend of cell 13 corresponding to the third temperature curve segment may differ from the temperature change trends corresponding to the fourth and fifth temperature curve segments, such as... Figure 5 The temperature change trend of cell 13 in the third temperature curve segment shown is different from the temperature change trend of cell 13 in the fourth and fifth temperature curve segments, and the temperature change trend of cell 13 in the fourth temperature curve segment is different from the temperature change trend of cell 13 in the fifth temperature curve segment.

[0082] In the above scheme, the third target temperature change curve includes a third temperature curve segment, a fourth temperature curve segment, and a fifth temperature curve segment connected in sequence, which represent the different temperature changes of the third target temperature change curve when powered off. This provides parameter support for statistical analysis of cell operating conditions and cell status calculation, thereby effectively enabling the prediction of cell temperature during the BMS power-off process.

[0083] In some embodiments, in the third temperature curve segment, the rate of change from the first cell temperature to the first ambient temperature is the ratio of the difference between the first ambient temperature and the first cell temperature to the first duration; in the fourth temperature curve segment, the rate of change of the first ambient temperature is kept at zero; in the fifth temperature curve segment, the rate of change from the first ambient temperature to the second cell temperature is the ratio of the difference between the second cell temperature and the first ambient temperature to the second duration.

[0084] Taking a scenario where the temperature of the first battery cell is higher than the first ambient temperature, and the first ambient temperature is higher than the temperature of the second battery cell, the rate of change from the temperature of the first battery cell to the temperature of the second battery cell can be obtained by subtracting the temperature of the first battery cell from the temperature of the second battery cell, and then dividing this result by the total power-down time. The rate of change can be the average rate of change, for example... Figure 5 middle The average rate of change is calculated from the slopes corresponding to all moments within the time period. In the fourth temperature curve segment, the rate of change at the first ambient temperature remains zero, as shown below. Figure 5 middle The curve segment within the time period shows a slope of zero. The rate of change from the first ambient temperature to the second cell temperature can be obtained by dividing the second cell temperature by the first ambient temperature and the difference between the total power-down time and the first power-down time. This rate of change can be the average rate of change, for example... Figure 5 middle The average rate of change is calculated from the slopes at all points within the time period. The different trends in the third, fourth, and fifth temperature curve segments are characterized by different rates of temperature decrease. It should be noted that a negative slope on this curve indicates a decreasing temperature over time.

[0085] In the above scheme, by plotting a third temperature curve segment including the rate of change from the first cell temperature to the first ambient temperature, a fourth temperature curve segment maintaining the rate of change at the first ambient temperature, and a fifth temperature curve segment including the rate of change from the first ambient temperature to the second cell temperature, the temperature change information of the cell 13 can be observed more directly. This provides parameter support for statistical analysis of cell operating conditions and calculation of cell status, thereby effectively enabling the prediction of the temperature of the cell 13 during the power-down process of BMS11.

[0086] In some embodiments, the method includes: powering down the BMS 11 after a preset power-on time.

[0087] The preset time can be a power-on hold time preset in BMS 11, for example, 30 seconds. After the preset power-on time, BMS 11 powers off; that is, after the preset power-on hold time is reached, BMS 11 powers off. For example, after a 30-second power-on hold, BMS 11 powers off. BMS 11 can use an RTC to time itself after power-on, so that it automatically powers off when the RTC timer reaches the preset time. When BMS 11 powers off, it also acquires the first cell temperature and the first ambient temperature of cell 13.

[0088] In the above scheme, after the BMS 11 is powered on for a preset time, the BMS 11 is powered off and the first cell temperature and the first ambient temperature of the cell 13 at the time the BMS 11 is powered off are collected to provide data support for subsequent temperature prediction.

[0089] In some embodiments, the method includes: in response to the total power-down time from the power-down of BMS 11 to the next power-up of BMS 11 reaching a preset value, setting a preset time for the next power-up of BMS 11.

[0090] The preset value can be the total power-down time from the power-down of BMS 11 to its next power-up, for example, 8 hours. The preset time for the next power-up of BMS 11 is, for example, in response to the power-down time of BMS 11 reaching 8 hours, BMS 11 will power on again and maintain this for 30 seconds. The total power-down duration during the power-down period of BMS 11 can be obtained through RTC timing, so that when the RTC timing reaches the preset value, BMS 11 will power on again and maintain the preset time, and the second cell temperature and second ambient temperature of cell 13 will be acquired during power-up.

[0091] In the above scheme, by setting a preset value for the total power-down time from the power-down of BMS 11 to the next power-up of BMS 11, the power-down time of BMS 11 is maintained at the preset time during the next power-up after reaching the preset value. The second cell temperature and the second ambient temperature of cell 13 are collected during the next power-up of BMS 11 to provide data support for subsequent temperature prediction.

[0092] In some embodiments, such as Figure 6 As shown, Figure 6 This is a flowchart illustrating the cell temperature prediction method of some embodiments of this application. Figure 2 This includes the following steps:

[0093] Step S61: After the BMS is powered on for a preset time, the BMS is powered off.

[0094] After BMS 11 is powered on and reaches the preset time via RTC timing, BMS is powered off.

[0095] Step S62: Obtain the first cell temperature and the first ambient temperature of the cell at the first moment within the first preset time period before the BMS is powered off.

[0096] Specifically, the temperature of the surface of the battery cell 13 is measured by an NTC thermistor 14 placed on the surface of the battery cell 13, and the temperature of the environment in which the battery cell 13 is located is measured by an NTC thermistor 14 placed in the environment in which the battery cell 13 is located. The measurement method can be continuous measurement, that is, the temperature of the surface of the battery cell 13 and the temperature of the environment in which the battery cell 13 is located are continuously acquired by the NTC thermistor 14, thereby obtaining the first battery cell temperature of the battery cell 13 and the first ambient temperature of the environment in which the battery cell 13 is located at a first moment within a first preset time period before the BMS 11 is powered off. For example, the first battery cell temperature of the battery cell 13 and the first ambient temperature of the environment in which the battery cell 13 is located are obtained 0.5 seconds before the BMS 11 is powered off. The first preset time period can be 1 second.

[0097] Step S63: The time from BMS power-down to the next BMS power-on reaches a preset value, and the next BMS power-on takes a preset time.

[0098] The preset value can be 8 hours, and the preset time can be 30 seconds. That is to say, after BMS 11 is powered off, if the duration obtained by BMS11 through RTC timing reaches 8 hours, then BMS 11 will power on for 30 seconds.

[0099] Step S64: Obtain the second cell temperature and the second ambient temperature of the cell at the second moment within the second preset time period after the BMS is powered on next time.

[0100] The second cell temperature and the second ambient temperature can also be obtained using NTC thermistors 14, which are used to measure the first cell temperature and the first ambient temperature, respectively. This allows for the acquisition of the second cell temperature and the second ambient temperature of cell 13 at a second moment within a second preset time period after the next power-on of the BMS 11. For example, the acquisition of the second cell temperature of cell 13 and the second ambient temperature of the environment in which cell 13 is located 0.5 seconds after the next power-on of the BMS 11. The second preset time period can be 1 second.

[0101] It should be noted that the prerequisite for step S62 is step S61, that is, after a preset power-on time, BMS 11 autonomously powers down. In one application scenario, the prerequisite for step S62 can be the response to BMS 11 powering down. Similarly, the prerequisite for step S64 is step S63, that is, in response to BMS 11 powering down, the time between BMS 11 powering down and its next power-on reaches a preset value, and BMS 11 autonomously powers on for a preset time. In one application scenario, the prerequisite for step S64 can be the response to BMS 11 powering on.

[0102] like Figure 7 As shown, Figure 7 This is a schematic diagram of the periodic sampling of the BMS in some embodiments of this application. The BMS 11 is started once every 8 hours and held for 30 seconds. When it is turned off, it performs power-down sampling, including obtaining the first cell temperature of the battery cell 13 and the first ambient temperature of the environment where the battery cell 13 is located at a first moment within a first preset time period before the BMS 11 is powered off. When it is started, it performs power-on sampling, including obtaining the second cell temperature of the battery cell 13 and the second ambient temperature of the environment where the battery cell 13 is located at a second moment within a second preset time period after the BMS 11 is powered on again, thereby predicting the temperature of the battery cell 13 during the power-down process of the BMS 11.

[0103] During the process from BMS 11 power-down to its next power-on, such as Figure 8 As shown, the cell temperature prediction process also includes the following steps:

[0104] Step S81: Obtain the first duration and the total power-off duration.

[0105] Specifically, the first duration is the time it takes for the temperature of the battery cell 13 to change from the first battery cell temperature to the first ambient temperature. For example, the average rate of change of the temperature of the battery cell 13 from the first battery cell temperature to the first ambient temperature is first calculated. Then, the first duration of temperature change of cell 13 from the first cell temperature to the first ambient temperature is calculated by formula (1) shown below.

[0106]

[0107] In calculating the first time interval during which the temperature of cell 13 changes from the first cell temperature to the first ambient temperature, the formula (1) contains... and These represent the temperatures of the first battery cell, respectively. and the first ambient temperature , The temperature of cell 13 is characterized from Reduce to The weighted average of the instantaneous rates of change at each moment within a time period, i.e., the average rate of change. The value is a positive number, for example, a rate of 1℃ / s. Or... Replace formula (1) To obtain . This is the first duration.

[0108] Regarding the temperature of cell 13, from the temperature of the first cell... Change to the first ambient temperature average rate of change We can first calculate the temperature of cell 13 from the temperature of the first cell. Change to the first ambient temperature The instantaneous rate of change during the process is shown in formula (2). Subsequently, the weighted average of each instantaneous rate of change is calculated to obtain the average rate of change. .

[0109]

[0110] in, The heat transfer coefficient of cell 13. This refers to the contact area between battery cell 13 and the environment. For the heat capacity of cell 13, and The temperatures of cell 13 are respectively from the temperature of the first cell. Change to the first ambient temperature The temperature corresponding to a certain instantaneous temperature change during the process. To calculate the temperature of cell 13 from the first cell temperature Change to the first ambient temperature The instantaneous rate of change of, where When the instantaneous rate of change is negative, it can be calculated based on the absolute value of the instantaneous rate of change when using the instantaneous rate of change to calculate the average rate of change.

[0111] The total power-down time can be obtained using the RTC in BMS 11. For example, the first cell temperature of cell 13 can be obtained by the RTC before BMS 11 is powered down. and the first ambient temperature The timing begins at the moment BMS 11 obtains the second cell temperature of cell 13 after the next power-on. Second ambient temperature The timer ends at the specified moment, thus obtaining the total power-off duration.

[0112] Step S82: In response to the first duration being greater than or equal to the total power-down duration, obtain the first target temperature change curve.

[0113] The response occurs when the first power-off duration is greater than or equal to the total power-off duration, meaning that the temperature of cell 13 has not yet decreased from the first cell temperature. Change to the first ambient temperature BMS 11 has already started the next power-on, or the temperature of cell 13 has just dropped from the temperature of the first cell. Change to the first ambient temperature The next time BMS 11 is powered on.

[0114] The obtained first target temperature change curve is as follows Figure 3 As shown, if the first duration is greater than the total power-down duration, that is... > At this point, the first target temperature curve is the temperature of cell 13 from the first cell temperature. Start and The temperature change curve changes over a period of time. The temperature of cell 13 at the end of the time period can be compared with the first ambient temperature. Different, for example, Figure 3 middle At the end of the time period, the temperature of cell 13 was higher than the initial ambient temperature. If the first duration equals the total power-off duration, that is... = At this point, the first target temperature curve is the temperature of cell 13 from the first cell temperature. Change to the first ambient temperature The temperature change curve, that is Temperature variation curves over a time period. It should be noted that the figure does not show the temperature of the second cell in response to the next power-on of BMS 11. The temperature change curve shows a slight increase, or in other words, the temperature of the second cell responds to the next power-on of BMS 11. The slight increase in temperature change can be ignored, or in other words, the second moment within the second preset time period can be shortened to reduce prediction error. For example, the second cell temperature can be measured 0.1 seconds after the BMS11 is powered on next. .

[0115] Step S83: In response to the first duration being less than the total power-down duration, obtain the second duration.

[0116] Specifically, the second duration is the time it takes for the temperature of cell 13 to change from the first ambient temperature to the second cell temperature. For example, it can be calculated using the above formulas (1) and (2), where formula (1) contains... and These represent the first ambient temperature. Second ambient temperature and in formula (2) and The temperatures of cell 13 are respectively from the first ambient temperature. Change to the second ambient temperature The second duration is obtained by determining the temperature corresponding to a certain instantaneous temperature change during the process. .

[0117] Step S84: In response to the sum of the first duration and the second duration being greater than the total power-down duration, obtain the second target temperature change curve.

[0118] In response to the sum of the first duration and the second duration being greater than the total power-down duration, that is, the temperature of cell 13 changes from the first cell temperature within the first duration. To the first ambient temperature Then, the difference between the total power-down time and the first duration is calculated from the first ambient temperature. Change to the temperature of the second cell .

[0119] The obtained temperature change curve of the second target is as follows Figure 4 As shown, the sum of the first duration and the second duration is greater than the total power-down duration, that is... + > The second target temperature change curve obtained at this time is the temperature of cell 13 at... and The curve segments within the time period are solid lines, which shows... Less than That is, the temperature of cell 13 drops from the first ambient temperature. Change to the temperature of the second cell The actual duration is less than the second duration, therefore, The average rate of change over the time period is greater than The average rate of change over the time period The dashed curve segment within the time period and The solid line segments within the time period are connected. For example, when the sum of the first and second time periods equals the total power-off time, the temperature change curve of cell 13 is the solid line segment within the time period t1. The time interval is represented by a dashed curve segment. Among them, The instantaneous rate of temperature change during the time period is shown in formula (3). The temperature of the battery cell is from the first ambient temperature. Reduce to the temperature of the second cell The instantaneous rate of change, thus based on The average rate of change is obtained by weighting the instantaneous rate of change at each moment within the time period.

[0120]

[0121] Step S85: In response to the sum of the first duration and the second duration being less than or equal to the total power-down duration, obtain the third target temperature change curve.

[0122] The response that the sum of the first duration and the second duration is less than the total power-down duration indicates that the temperature of cell 13 has decreased from the first cell temperature. Change to the first ambient temperature And after maintaining this for a period of time, then from the first ambient temperature Change to the temperature of the second cell ,like Figure 5 As shown, the temperature of cell 13 is at From the temperature of the first cell within a certain time period Reduce to the first ambient temperature and at the first ambient temperature Keep Duration, then in From the first ambient temperature within the time period Change to the temperature of the second cell That is, to obtain the temperature change curve of the third target, such as Figure 5 As shown.

[0123] The response that the sum of the first duration and the second duration equals the total power-down duration indicates that the temperature of cell 13 has decreased from the first cell temperature. Change to the first ambient temperature Then, starting from the first ambient temperature Change to the temperature of the second cell That is to say, at this time =0, that is Figure 5 In Time period and By connecting time periods (not shown in the figure), the temperature change curve of the third target can be obtained.

[0124] Please see Figure 9 , Figure 9 This is a schematic diagram of the structure of a cell temperature prediction system according to some embodiments of this application. The cell temperature prediction system includes a first acquisition module 91, a second acquisition module 92, and a prediction module 93. The first acquisition module 91 is used to acquire the first cell temperature of the cell 13 and the first ambient temperature of the environment in which the cell 13 is located when the BMS 11 is powered off. The second acquisition module 92 is used to acquire the second cell temperature of the cell 13 and the second ambient temperature of the environment in which the cell 13 is located when the BMS 11 is powered on again. The prediction module 93 is used to predict the temperature change curve of the cell 13 from the power-off of the BMS 11 to the next power-on of the BMS 11 based on the first cell temperature, the first ambient temperature, the second cell temperature, and the second ambient temperature.

[0125] In the above scheme, by acquiring the first cell temperature of the battery cell 13 connected to the BMS 11 and the first ambient temperature of the environment where the battery cell 13 is located when the BMS 11 is powered off; acquiring the second cell temperature of the battery cell 13 and the second ambient temperature of the environment where the battery cell 13 is located when the BMS 11 is powered on again; based on the first cell temperature, the first ambient temperature, the second cell temperature, and the second ambient temperature, the temperature change curve of the battery cell 13 during the process from the power-off of the BMS 11 to the next power-on of the BMS 11 is predicted. This enables the prediction of the temperature of the battery cell 13 during the power-off process of the BMS 11 by collecting the actual temperature data during the power-off and next power-on processes of the BMS 11, thereby providing parameter support for statistical analysis of battery cell operating conditions and calculation of battery cell status.

[0126] In some embodiments, the first acquisition module 91 acquires the first cell temperature and the first ambient temperature of the battery cell when the BMS is powered off, including: acquiring the temperature of the battery cell 13 at a first moment within a first preset time period before the BMS 11 is powered off, as the first cell temperature, wherein the first moment is any moment within the first preset time period; and acquiring the temperature of the environment where the battery cell 13 is located at the first moment, as the first ambient temperature.

[0127] In the above scheme, the acquisition time of the first cell temperature and the first ambient temperature is set to the first moment within the first preset time before the BMS 11 is powered off. By acquiring the temperature of the cell 13 adjacent to the BMS 11 before it is powered off and the temperature of the environment where the cell 13 is located, respectively, the first cell temperature and the first ambient temperature can be more accurately reflected. This provides real and accurate data support for the subsequent prediction of the temperature change curve of the cell 13, thereby effectively predicting the temperature of the cell 13 during the power-off process of the BMS 11.

[0128] In some embodiments, the second acquisition module 92 acquires the second cell temperature and the second ambient temperature of the cell 13 when the BMS is powered on again, including: acquiring the temperature of the cell 13 at a second moment within a second preset time period after the BMS is powered on again, as the second cell temperature, wherein the second moment is any moment within the second preset time period; and acquiring the temperature of the environment where the cell 13 is located at the second moment, as the second ambient temperature.

[0129] In the above scheme, the acquisition time of the second cell temperature and the second ambient temperature is set to the second moment within the second preset time after the BMS 11 is powered on next time. By acquiring the temperature of the cell 13 and the temperature of the environment where the cell 13 is located after the next power-on of the adjacent BMS 11, respectively, the second cell temperature and the second ambient temperature can better reflect the true values ​​of the temperature of the cell 13 and the temperature of the environment where the cell 13 is located at the next power-on of the BMS 11. This provides real and accurate data support for the subsequent prediction of the temperature change curve of the cell 13, thereby effectively realizing the prediction of the temperature of the cell 13 during the power-off process of the BMS 11.

[0130] In some embodiments, the prediction module 93 predicts the temperature change curve of the cell 13 during the period from the power-down of BMS 11 to the next power-up of BMS 11, including: acquiring a first time duration during which the temperature of the cell 13 changes from a first cell temperature to a first ambient temperature; and in response to the first time duration being greater than or equal to the total power-down time from the power-down of BMS 11 to the next power-up of BMS 11, acquiring the temperature change curve of the cell 13 as a first target temperature change curve, wherein the first target temperature change curve represents the change curve from the first cell temperature to the second cell temperature within the total power-down time.

[0131] In the above scheme, by obtaining the first time taken for the first cell temperature to reach the first ambient temperature, and comparing the first time with the total power-down time, a first target temperature change curve with the first time being greater than or equal to the total power-down time is obtained, thereby predicting the cell temperature during the power-down process of BMS 11, and providing parameter support for statistical analysis of cell operating conditions and cell status calculation.

[0132] In some embodiments, in the first target temperature change curve, the rate of change from the first cell temperature to the second cell temperature is the ratio of the difference between the second cell temperature and the first cell temperature to the total power-down time.

[0133] In the above scheme, the first target temperature change curve is predicted by plotting a curve including the rate of change from the temperature of the first cell to the temperature of the second cell, thereby realizing the prediction of the cell temperature during the power-down process of BMS 11, and providing parameter support for statistical cell operating conditions and cell state calculation.

[0134] In some embodiments, the prediction module 93 predicts the temperature change curve of the battery cell 13 during the process from power-down of BMS 11 to the next power-up of BMS 11, including: acquiring a first duration for the temperature of the battery cell 13 to change from a first battery cell temperature to a first ambient temperature; in response to the first duration being less than the total power-down duration from power-down of BMS 11 to the next power-up of BMS 11, acquiring a second duration for the temperature of the battery cell 13 to change from the first ambient temperature to a second battery cell temperature; in response to the sum of the first duration and the second duration being greater than the total power-down duration, acquiring the temperature change curve of the battery cell 13 as a second target temperature change curve, wherein the second target temperature change curve represents the change curve from the first battery cell temperature to the second battery cell temperature within the total power-down duration, and includes a first temperature curve segment and a second temperature curve segment, the first temperature curve segment representing the change from the first battery cell temperature to the first ambient temperature within the first duration, and the second temperature curve segment representing the change from the first ambient temperature to the second battery cell temperature within the difference between the total power-down duration and the first duration.

[0135] In the above scheme, by obtaining the first time taken for the first cell temperature to rise to the first ambient temperature, and comparing the first time with the total power-down time, a second target temperature change curve is obtained in which the sum of the first time and the second time is greater than the total power-down time. This enables the prediction of the cell temperature during the power-down process of BMS 11, providing parameter support for statistical analysis of cell operating conditions and cell status calculation.

[0136] In some embodiments, in the first temperature curve segment, the rate of change from the first cell temperature to the first ambient temperature is the ratio of the difference between the first ambient temperature and the first cell temperature to the first duration; in the second temperature curve segment, the rate of change from the first ambient temperature to the second cell temperature is the ratio of the difference between the second cell temperature and the first ambient temperature to the difference between the total power-down time and the first duration.

[0137] In the above scheme, by plotting a first temperature curve segment including the rate of change from the first cell temperature to the first ambient temperature and a second temperature curve segment including the rate of change from the first ambient temperature to the second cell temperature, the cell temperature during the power-down process of BMS 11 can be predicted, providing parameter support for statistical cell operating conditions and cell state calculation.

[0138] In some embodiments, the prediction module 93 predicts the temperature change curve of the battery cell 13 during the period from power-down of BMS 11 to the next power-up of BMS 11, including: acquiring a first time duration during which the temperature of the battery cell 13 changes from a first battery cell temperature to a first ambient temperature; in response to the first time duration being less than the total power-down time from power-down of BMS 11 to the next power-up of BMS 11, acquiring a second time duration during which the temperature of the battery cell 13 changes from the first ambient temperature to a second battery cell temperature; in response to the sum of the first time duration and the second time duration being less than or equal to the total power-down time, acquiring the temperature change curve of the battery cell 13 as a third target temperature change curve, wherein the third target temperature change curve represents the change curve from the first battery cell temperature to the second battery cell temperature within the total power-down time.

[0139] In the above scheme, by obtaining the first time taken for the cell temperature to change to the first ambient temperature, and comparing the first time with the total power-down time, and then, in response to the first time being less than the total power-down time, the second time for the cell 13 to change from the first ambient temperature to the second cell temperature is calculated. Thus, in response to the sum of the first time and the second time being less than or equal to the total power-down time, the difference between the total power-down time and the sum of the first time and the second time is obtained after the first cell temperature changes to the first ambient temperature. Then, the cell temperature changes from the first ambient temperature to the second cell temperature in the second time, thereby obtaining the third target temperature change curve. This provides parameter support for statistical analysis of cell operating conditions and cell status calculation, thereby effectively predicting the temperature of the cell 13 during the power-down process of BMS 11.

[0140] In some embodiments, the third target temperature change curve includes a third temperature curve segment, a fourth temperature curve segment, and a fifth temperature curve segment connected in sequence. The third temperature curve segment represents the change from the first cell temperature to the first ambient temperature within the first duration. The fourth temperature curve segment represents the maintenance at the first ambient temperature within the difference between the total power-down duration and the sum of the first duration and the second duration. The fifth temperature curve segment represents the change from the first ambient temperature to the second cell temperature within the second duration.

[0141] In the above scheme, the third target temperature change curve includes a third temperature curve segment, a fourth temperature curve segment, and a fifth temperature curve segment connected in sequence, which represent the different temperature changes of the third target temperature change curve when powered off. This provides parameter support for statistical analysis of cell operating conditions and cell status calculation, thereby effectively enabling the prediction of cell temperature during the BMS power-off process.

[0142] In some embodiments, in the third temperature curve segment, the rate of change from the first cell temperature to the first ambient temperature is the ratio of the difference between the first ambient temperature and the first cell temperature to the first duration; in the fourth temperature curve segment, the rate of change of the first ambient temperature is kept at zero; in the fifth temperature curve segment, the rate of change from the first ambient temperature to the second cell temperature is the ratio of the difference between the second cell temperature and the first ambient temperature to the second duration.

[0143] In the above scheme, by plotting a third temperature curve segment including the rate of change from the first cell temperature to the first ambient temperature, a fourth temperature curve segment maintaining the rate of change at the first ambient temperature, and a fifth temperature curve segment including the rate of change from the first ambient temperature to the second cell temperature, the temperature change information of the cell 13 can be observed more directly. This provides parameter support for statistical analysis of cell operating conditions and calculation of cell status, thereby effectively enabling the prediction of the temperature of the cell 13 during the power-down process of BMS11.

[0144] In some embodiments, BMS 11 is powered off after a preset power-on time.

[0145] In the above scheme, after the BMS 11 is powered on for a preset time, the BMS 11 is powered off and the first cell temperature and the first ambient temperature of the cell 13 at the time the BMS 11 is powered off are collected to provide data support for subsequent temperature prediction.

[0146] In some embodiments, in response to the total power-down time from the power-down of BMS 11 to the next power-up of BMS 11 reaching a preset value, the next power-up time of BMS 11 is preset.

[0147] In the above scheme, by setting a preset value for the total power-down time from the power-down of BMS 11 to the next power-up of BMS 11, the power-down time of BMS 11 is maintained at the preset time during the next power-up after reaching the preset value. The second cell temperature and the second ambient temperature of cell 13 are collected during the next power-up of BMS 11 to provide data support for subsequent temperature prediction.

[0148] In some embodiments, the BSM is used to perform the cell temperature prediction method in the above embodiments, wherein the BMS 11 is as follows: Figure 1 As shown in the image.

[0149] The BMS 11 in this application is used to perform at least one of the following functions for battery cells: state monitoring, state analysis, charge / discharge control, safety protection, thermal management, high-voltage power distribution, and information management. In addition, the battery management system 11 in this application can also perform the functions of a controller in an electrical device, such as a vehicle control unit (VCU) or a motor control unit (MCU), etc., and this application does not impose any limitations on this.

[0150] It should be noted that the battery management system 11 in this application can be integrated as a controller into the battery device, such as into the battery pack or energy storage box.

[0151] The battery management system 11 in this application can also be integrated into electrical devices as a controller, such as in a vehicle or in a vehicle chassis.

[0152] The battery management system 11 in this application can also be integrated into the charging device as a controller, such as into the charging device or the battery swapping device.

[0153] The battery management system 11 in this application can also be deployed as control software on a server. The server can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms, such as vehicle networking cloud, APP backend, etc.

[0154] Please see Figure 10 , Figure 10 This is a schematic diagram of the structure of a battery device according to some embodiments of this application. The battery device 100 includes a battery cell 13 and a battery management system 11, wherein the battery cell 13 is connected to the battery management system 11.

[0155] In this application, the battery device 100 includes at least one battery cell 13 and a battery management system 11. The connection method between multiple battery cells can be conventional in the art, such as series connection, parallel connection, or a hybrid connection that includes these connection methods. Hybrid connection refers to the series and parallel connection between multiple batteries, and there is no particular limitation on this.

[0156] Please see Figure 11 , Figure 11 This is a schematic diagram of the structure of an electrical device according to some embodiments of this application. The electrical device 110 includes a battery device 100.

[0157] In this application, the power-consuming device 110 includes a battery device 100 and an electrical load. The power-consuming device 110 can be, but is not limited to, power equipment (such as electric vehicles, electric cars, electric ships, spacecraft), electronic equipment (such as mobile phones, tablets, laptops, bionic machines, digital cameras, electric toys, etc.), wearable devices (such as watches, bracelets, VR glasses, etc.), energy storage power stations, etc.

[0158] Please see Figure 12 , Figure 12 This is a schematic diagram of the structure of an electronic device according to some embodiments of this application. The electronic device 120 includes a memory 121 and a processor 122. The processor 122 is used to execute program instructions stored in the memory 121 to implement the steps in any of the above embodiments of the cell temperature prediction method. In a specific implementation scenario, the electronic device 120 may include, but is not limited to, a microcomputer or a server. Furthermore, the electronic device 120 may also include a laptop computer, tablet computer, or other carrier device, which is not limited here.

[0159] Specifically, processor 122 controls itself and memory 121 to implement the steps in any of the above-described embodiments of the cell temperature prediction method. Processor 122 can also be referred to as a CPU (Central Processing Unit). Processor 122 may be an integrated circuit chip with signal processing capabilities. Processor 122 can also be a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. A general-purpose processor can be a microprocessor or any conventional processor. Furthermore, processor 122 can be implemented using integrated circuit chips.

[0160] Please see Figure 13 , Figure 13 This is a schematic diagram of the framework of a non-volatile computer-readable storage medium according to some embodiments of this application. The non-volatile computer-readable storage medium 130 stores program instructions 1301 that can be executed by the processor 122. The program instructions 1301 are used to implement the steps of any of the above-described embodiments of the cell temperature prediction method.

[0161] In the above scheme, by acquiring the first cell temperature of the battery cell 13 connected to the BMS 11 and the first ambient temperature of the environment where the battery cell 13 is located when the BMS 11 is powered off; acquiring the second cell temperature of the battery cell 13 and the second ambient temperature of the environment where the battery cell 13 is located when the BMS 11 is powered on again; based on the first cell temperature, the first ambient temperature, the second cell temperature, and the second ambient temperature, the temperature change curve of the battery cell 13 during the process from the power-off of the BMS 11 to the next power-on of the BMS 11 is predicted. This enables the prediction of the temperature of the battery cell 13 during the power-off process of the BMS 11 by collecting the actual temperature data during the power-off and next power-on processes of the BMS 11, thereby providing parameter support for statistical analysis of battery cell operating conditions and calculation of battery cell status.

[0162] In some embodiments, the functions or modules of the apparatus provided in this disclosure can be used to perform the methods described in the above method embodiments. The specific implementation can be referred to the description of the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0163] The description of the various embodiments above tends to emphasize the differences between the various embodiments. The similarities or similarities between them can be referred to, and for the sake of brevity, they will not be repeated here.

[0164] In this document, the terms “coupled,” “connected,” and “linked” are used to refer to a direct or indirect connection between two objects. For example, when describing a first object coupled to a second object, the first object is considered to be coupled to the second object even if it is not in direct physical contact with the second object, but is indirectly in contact with the second object through a conductor and / or other objects. The term “circuit” is widely used and intended to include hardware implementations of both electronic components and conductors that, when connected and configured, enable the performance of the functions described in this application, without being limited to the type of electronic circuit.

[0165] When describing systems, apparatus, and methods, the accompanying drawings and / or descriptions use terms such as block, module, component, unit, step, process, and algorithm. For example, the functions corresponding to these terms can be implemented using hardware.

[0166] The various operations or methods described above can be performed by any suitable component capable of performing the corresponding function. This component may include various hardware and / or software components and / or modules, including but not limited to circuits, application-specific integrated circuits (ASICs), or processors.

[0167] One or more of the components, steps, features, and / or functions disclosed in this application may be rearranged and / or combined into a single component, step, feature, or function, or distributed among several components, steps, or functions. Those skilled in the art may also add additional elements, components, steps, and / or functions without departing from the scope disclosed herein.

[0168] In the several embodiments provided in this application, it should be understood that the disclosed methods and apparatus can be implemented in other ways. For example, the apparatus implementations described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, units or components may be combined or integrated into another system, or some features may be ignored or not executed. In another image location, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0169] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it 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 all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A method for predicting battery cell temperature, characterized in that, include: Obtain the first cell temperature and the first ambient temperature of the environment in which the cell is located when the BMS is powered off; The second cell temperature and the second ambient temperature of the environment in which the cell is located are obtained when the BMS is powered on for the next time. Based on the first cell temperature, the first ambient temperature, the second cell temperature, and the second ambient temperature, the temperature change curve of the cell is predicted during the process from the BMS power-off to the next power-on of the BMS. The temperature change curve is the target temperature change curve, which represents the change curve from the first cell temperature to the second cell temperature during the total power-off time from the BMS power-off to the next power-on of the BMS. The target temperature change curve includes a first temperature curve segment and a second temperature curve segment connected together. The first temperature curve segment represents the change from the first cell temperature to the first ambient temperature within a first duration. The second temperature curve segment represents the change from the first ambient temperature to the second cell temperature within the difference between the total power-down time and the first duration. The first duration is less than the total power-down time, and the sum of the first duration and the second duration is greater than the total power-down time; or The target temperature change curve includes a third temperature curve segment, a fourth temperature curve segment, and a fifth temperature curve segment connected in sequence. The third temperature curve segment represents the change from the first cell temperature to the first ambient temperature within the first duration. The fourth temperature curve segment represents the maintenance at the first ambient temperature within the difference between the total power-down time and the sum of the first duration and the second duration. The fifth temperature curve segment represents the change from the first ambient temperature to the second cell temperature within the second duration. The first duration is less than the total power-down time, and the sum of the first duration and the second duration is less than or equal to the total power-down time. Wherein, the first duration is the time it takes for the temperature of the battery cell to change from the first battery cell temperature to the first ambient temperature, and the second duration is the time it takes for the temperature of the battery cell to change from the first ambient temperature to the second battery cell temperature, and the second ambient temperature is used to determine the second duration.

2. The method according to claim 1, characterized in that, The process of obtaining the first cell temperature and the first ambient temperature of the environment in which the cell is located when the BMS is powered off includes: The temperature of the battery cell at a first moment within a first preset time period before the BMS is powered off is obtained as the first battery cell temperature, wherein the first moment is any moment within the first preset time period; The temperature of the environment in which the battery cell is located at the first moment is obtained and used as the first ambient temperature.

3. The method according to claim 1, characterized in that, The step of obtaining the second cell temperature of the battery cell and the second ambient temperature of the environment in which the battery cell is located when the BMS is powered on next includes: The temperature of the battery cell at a second moment within a second preset time period after the next power-on of the BMS is obtained, and is used as the second battery cell temperature, wherein the second moment is any moment within the second preset time period; The temperature of the environment in which the battery cell is located at the second time point is obtained as the second ambient temperature.

4. The method according to claim 1, characterized in that, The method of predicting the temperature change curve of the battery cell from the time the BMS is powered off to the time the BMS is powered on again, based on the temperature of the first battery cell, the first ambient temperature, the temperature of the second battery cell, and the second ambient temperature, includes: Obtain the first duration; In response to the first duration being less than the total power-down duration, the second duration is obtained; In response to the fact that the sum of the first duration and the second duration is greater than the total power-off duration, the temperature change curve of the battery cell is obtained as the target temperature change curve, which includes the first temperature curve segment and the second temperature curve segment connected together.

5. The method according to claim 4, characterized in that, In the first temperature curve segment, the rate of change from the first cell temperature to the first ambient temperature is the ratio of the difference between the first ambient temperature and the first cell temperature to the first duration. In the second temperature curve segment, the rate of change from the first ambient temperature to the second cell temperature is the ratio of the difference between the second cell temperature and the first ambient temperature to the difference between the total power-down time and the first duration.

6. The method according to claim 1, characterized in that, The method of predicting the temperature change curve of the battery cell from the time the BMS is powered off to the time the BMS is powered on again, based on the temperature of the first battery cell, the first ambient temperature, the temperature of the second battery cell, and the second ambient temperature, includes: Obtain the first duration; In response to the first duration being less than the total power-down duration, the second duration is obtained; In response to the sum of the first duration and the second duration being less than or equal to the total power-down duration, the temperature change curve of the battery cell is obtained as the target temperature change curve, which includes the third temperature curve segment, the fourth temperature curve segment, and the fifth temperature curve segment connected in sequence.

7. The method according to claim 6, characterized in that, In the third temperature curve segment, the rate of change from the first cell temperature to the first ambient temperature is the ratio of the difference between the first ambient temperature and the first cell temperature to the first duration. In the fourth temperature curve segment, the rate of change of the first ambient temperature is kept at zero. In the fifth temperature curve segment, the rate of change from the first ambient temperature to the second cell temperature is the ratio of the difference between the second cell temperature and the first ambient temperature to the second duration.

8. The method according to any one of claims 1-7, characterized in that, The BMS is powered off after a preset power-on time.

9. The method according to claim 8, characterized in that, In response to the total power-down time from the power-down of the BMS to the next power-on of the BMS reaching a preset value, the BMS is powered on again for the preset time.

10. A battery management system, characterized in that, Used to perform the cell temperature prediction method as described in any one of claims 1-9.

11. A battery device, characterized in that, It includes a battery cell and a battery management system as described in claim 10, wherein the battery cell is connected to the BMS.

12. An electrical appliance, characterized in that, Includes the battery device as described in claim 11.

13. An electronic device, characterized in that, It includes a memory and a processor, the processor being configured to execute program instructions stored in the memory to implement the cell temperature prediction method according to any one of claims 1-9.

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