Battery pack air tightness detection method and system and computer readable storage medium

Abstract

The invention discloses a battery pack air tightness detection method and system and a computer readable storage medium. The battery pack air tightness detection method comprises the steps that the volume of a battery pack is determined; injecting gas into the battery pack until the gas pressure in the battery pack reaches a preset pressure; the first pressure and the first temperature of gas in the battery pack at the first moment and the second pressure and the second temperature of gas in the battery pack at the second moment are obtained, and the leakage rate of the battery pack is determined according to the first pressure, the first temperature, the second pressure, the second temperature, the volume of the battery pack and the duration between the second moment and the first moment. According to the battery pack air tightness detection method disclosed by the invention, the influence of the temperature and the volume of the battery pack on the air tightness detection result is considered, and the accuracy of air tightness detection can be improved.

Description

Technical Field

[0001] This application relates to the field of airtightness testing technology, and in particular to a method, system and computer-readable storage medium for testing the airtightness of a battery pack. Background Technology

[0002] Products with large cavities typically require airtightness testing before assembly. For example, in the manufacturing process of automotive power battery packs, airtightness testing is necessary to detect manufacturing defects and reduce safety hazards. However, current airtightness testing technologies are inefficient and lack accuracy. Summary of the Invention

[0003] This application provides a method, system, and computer-readable storage medium for testing the airtightness of a battery pack, in order to solve at least some of the problems in the related art.

[0004] This application provides a battery pack airtightness testing method, applied to a battery pack airtightness testing system. The battery pack airtightness testing method includes:

[0005] Determine the volume of the battery pack;

[0006] Gas is injected into the battery pack until the gas pressure inside the battery pack reaches a preset pressure.

[0007] The first pressure and first temperature of the gas inside the battery pack at a first moment, and the second pressure and second temperature of the gas inside the battery pack at a second moment are obtained.

[0008] The leakage rate of the battery pack is determined based on the first pressure, the first temperature, the second pressure, the second temperature, the volume of the battery pack, and the duration between the second time and the first time.

[0009] Optionally, determining the leakage rate of the battery pack based on the first pressure, the first temperature, the second pressure, the second temperature, the volume of the battery pack, and the duration between the second time and the first time includes:

[0010] The first pressure at the first temperature is converted into a third pressure at the second temperature based on the volume of the battery pack;

[0011] The leakage rate of the battery pack is determined based on the difference between the third pressure and the second pressure and the duration.

[0012] Optionally, the battery pack airtightness detection system includes a receiving cavity, and determining the volume of the battery pack includes:

[0013] Gases of equal amounts are injected into the containment cavity and the battery pack, respectively.

[0014] The temperature and pressure of the gas inside the containment cavity and the temperature and pressure of the gas inside the battery pack are obtained.

[0015] The volume of the battery pack is determined based on the volume of the receiving cavity, the temperature and pressure of the gas inside the receiving cavity, and the temperature and pressure of the gas inside the battery pack.

[0016] Optionally, after injecting gas into the battery pack until the gas pressure inside the battery pack reaches a preset pressure, the detection method further includes:

[0017] Within a first preset duration, the battery pack is controlled to maintain the preset pressure;

[0018] In the process of obtaining the first pressure and first temperature of the gas inside the battery pack at the first moment, and the second pressure and second temperature of the gas inside the battery pack at the second moment, the first moment is the moment after the end of the first preset duration, and the time interval between the first moment and the end of the first preset duration is less than the second preset duration.

[0019] Optionally, the battery pack airtightness testing system includes a receiving cavity, and after determining the volume of the battery pack, the testing method further includes:

[0020] The cavity and the battery pack are connected.

[0021] Determining the leakage rate of the battery pack based on the first pressure, the first temperature, the second pressure, the second temperature, the volume of the battery pack, and the duration between the second time and the first time includes:

[0022] The leakage rate of the battery pack is determined based on the first pressure, the first temperature, the second pressure, the second temperature, the volume of the battery pack, the volume of the receiving cavity, and the duration between the second time and the first time.

[0023] Optionally, injecting gas into the battery pack until the gas pressure inside the battery pack reaches a preset pressure includes:

[0024] Obtain the pressure of the gas inside the containment cavity;

[0025] If the pressure of the gas in the receiving cavity is greater than the preset pressure, the inflation of the receiving cavity will be suspended.

[0026] Optionally, obtaining the first pressure and first temperature of the gas inside the battery pack at a first moment, and the second pressure and second temperature of the gas inside the battery pack at a second moment, includes:

[0027] The first pressure and first temperature of the gas in the containment cavity at the first moment, and the second pressure and second temperature of the gas in the containment cavity at the second moment are obtained.

[0028] Optionally, the battery pack airtightness testing system includes a receiving cavity, and after the gas pressure inside the battery pack reaches a preset pressure through gas injection, the testing method further includes:

[0029] The amount of gas transferred from the containment cavity to the battery pack within a third preset time period is obtained.

[0030] The leakage rate of the battery pack is determined based on the transfer amount and the third preset duration.

[0031] Another aspect of this application provides a battery pack airtightness testing system, including a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor executes the program to implement a battery pack airtightness testing method.

[0032] In another aspect, this application provides a computer-readable storage medium storing a program that, when executed, implements a method for detecting the airtightness of a battery pack.

[0033] Compared with related technologies, the battery pack airtightness testing method, system, and computer-readable storage medium disclosed in this application include determining the volume of the battery pack. This takes into account the impact of the battery pack volume on airtightness testing, and the airtightness testing method provided in this application can test battery packs of different volumes, including those of unknown volume, thus expanding the testing range of the battery pack airtightness testing method.

[0034] The battery pack airtightness testing method disclosed in this application injects gas into the battery pack until the gas pressure inside the battery pack reaches a preset pressure. Thus, the battery pack can be tested for airtightness according to the testing pressure specified in the battery pack airtightness testing procedure, and the preset pressure can be adjusted according to the testing pressure specified in the testing procedure, thereby expanding the testing range of the airtightness testing method.

[0035] By acquiring the first pressure and first temperature of the gas inside the battery pack at a first moment, and the second pressure and second temperature of the gas inside the battery pack at a second moment, the leakage rate of the battery pack is determined based on the first pressure, first temperature, second pressure, second temperature, the volume of the battery pack, and the time interval between the second and first moments. Thus, the battery pack airtightness testing method considers the influence of temperature on the airtightness testing results, which can improve the accuracy of airtightness testing. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0037] Figure 1 This is a schematic flowchart illustrating a battery pack airtightness testing method according to one embodiment of this application.

[0038] Figure 2 for Figure 1 The flowchart of one embodiment of step 40 is shown.

[0039] Figure 3 This is a schematic diagram of the structure of an airtightness detection system according to one embodiment of this application.

[0040] Figure 4 for Figure 1 The flowchart of one embodiment of step 10 is shown.

[0041] Figure 5 This is a schematic diagram of the airtightness detection system according to another embodiment of this application.

[0042] Figure 6 for Figure 1 A flowchart illustrating another implementation of step 10 is shown.

[0043] Figure 7 This is a schematic flowchart illustrating a battery pack airtightness testing method according to another embodiment of this application.

[0044] Figure 8 This is a schematic flowchart of an airtightness testing method according to another embodiment of this application.

[0045] Figure 9 This is a structural block diagram of an airtightness detection system provided in one embodiment of this application. Detailed Implementation

[0046] This application provides a method, system, and computer-readable storage medium for testing the airtightness of a battery pack. The method, system, and computer-readable storage medium are described in detail below with reference to the accompanying drawings. Unless otherwise specified, the features described in the embodiments and implementations can be combined with each other.

[0047] Please refer to Figure 1 , Figure 1 This is a schematic flowchart of a battery pack airtightness testing method 1 according to an embodiment of this application. Figure 1 As shown, the battery pack airtightness testing method 1 provided in this application embodiment is applied to the battery pack airtightness testing system 2, and includes steps 10 to 40.

[0048] Step 10: Determine the volume of battery pack 3. Thus, the influence of the volume of battery pack 3 on airtightness testing is taken into account, and the airtightness testing method 1 provided in this application embodiment can test battery packs 3 with different volumes, including battery packs 3 with unknown volumes, thereby expanding the testing range of the battery pack airtightness testing method 1 disclosed in this application embodiment.

[0049] Step 20: Inject gas into the battery pack 3 until the gas pressure inside the battery pack 3 reaches the preset pressure. In this way, the airtightness of the battery pack 3 can be tested according to the test pressure specified in the airtightness test procedure of the battery pack 3. The preset pressure can be adjusted according to the test pressure specified in the test procedure to expand the test range of airtightness test method 1.

[0050] Step 30: Obtain the first pressure and first temperature of the gas inside battery pack 3 at a first moment, and the second pressure and second temperature of the gas inside battery pack 3 at a second moment. The first moment is the initial detection time for airtightness testing, and the second moment is the time after the first moment for testing. Through these two measurements, determine whether there is a leak in battery pack 3 within the time interval between the first and second moments, and determine the leakage rate of battery pack 3 within the time interval between the first and second moments.

[0051] Step 40: Determine the leakage rate of battery pack 3 based on the first pressure, first temperature, second pressure, second temperature, volume of battery pack 3, and duration between the second and first moments.

[0052] By acquiring the first pressure and first temperature at a first moment, and the second pressure and second temperature at a second moment, and analyzing the changes in the second pressure and second temperature compared to the first pressure and first temperature, the method further analyzes whether there is gas leakage and the leakage rate within the battery pack 3. Thus, the battery pack airtightness detection method 1 disclosed in this application considers the influence of temperature and the volume of the battery pack 3 on the airtightness detection results, thereby improving the accuracy of the airtightness detection.

[0053] Please refer to Figure 2 , Figure 2 for Figure 1 The flowchart illustrating one embodiment of step 40 is shown. Figure 2 In the embodiment shown, step 40 determines the leakage rate of the battery pack 3 based on the first pressure, the first temperature, the second pressure, the second temperature, the volume of the battery pack 3, and the duration between the second time and the first time, including steps 41 and 42.

[0054] Step 41: Based on the volume of battery pack 3, convert the first pressure at the first temperature into the third pressure at the second temperature;

[0055] Step 42: Determine the leakage rate of battery pack 3 based on the difference between the third pressure and the second pressure and the duration.

[0056] Specifically, if the first temperature at the first moment is T1 and the first pressure is P1, and the second temperature at the second moment is T2 and the second pressure is P2, and the volume of battery pack 3 is V1, then according to the ideal gas equation pV = nRT, where R is a constant, if the amount of substance n and the volume of the container V remain constant, then the pressure V is directly proportional to the temperature. That is, the higher the temperature, the greater the gas pressure. In other words, temperature affects gas pressure. If we only judge whether battery pack 3 has a leak based on the pressure difference between the second and first pressures, we are neglecting the influence of temperature on gas pressure.

[0057] Therefore, in this application, the first pressure at the first temperature is converted into a third pressure at the second temperature based on the volume of the battery pack 3. That is, an ideal gas equation is established at the first moment, and the amount of substance n1 at the first moment is calculated as P1V1 / RT1 based on the first pressure P1, the first temperature T1, and the volume V1 of the battery pack 3. Assuming that the battery pack 3 does not leak, the corresponding third pressure P3 at the second moment, when the second temperature is T2, is P1T2 / T1. The third pressure P3 corresponds to the same temperature as the second pressure P2, both being T2. Thus, the leakage rate of the battery pack 3 is determined based on the difference between the third pressure P3 and the second pressure P2, and the duration. This avoids the influence of temperature factors on determining whether the battery pack 3 leaks and the leakage rate, thereby improving the accuracy of the battery pack 3's airtightness detection.

[0058] In a specific embodiment, the first temperature T1 at the first moment is 296.15 K, and the first pressure P1 is 205.326 kPa. The second temperature T2 at the second moment is 296.25 K, and the second pressure P2 is 205.303 kPa. The time interval between the first and second moments is 1 minute, and the volume V1 of the battery pack 3 is 41 L. According to the ideal gas equation, the amount of substance at the first moment is n ≈ 3.41 mol. The third pressure P3 corresponding to the amount of substance n ≈ 3.41 mol at temperature T2 is calculated to be 205.395 kPa. The leakage rate of the battery pack 3 is (P3 - P2) / 1 = 0.092 kPa / min.

[0059] Please refer to Figure 3 and Figure 4 , Figure 3 This is a schematic diagram of the structure of an airtightness detection system 2 according to an embodiment of this application. Figure 4 for Figure 1 The flowchart illustrating one embodiment of step 10 is shown. Figure 3As shown, the airtightness testing system includes a receiving cavity 21, the volume of which is fixed and known. The airtightness testing system 2 also includes a gas source 22, which is connected to the receiving cavity 21 and also to the battery pack 3. A gas flow meter 23 is installed between the gas source 22 and the receiving cavity 21, and also between the gas source 22 and the battery pack 3. The gas source 22 is used to inject gas into the receiving cavity 21 and the battery pack 3, and the gas flow meter is used to measure the amount of gas injected into the receiving cavity 21 and the battery pack 3.

[0060] In this application's embodiments, the gas can be air or an inert gas such as nitrogen; this application does not impose any limitations on this. When the gas is air, it can be directly prepared using an air compressor, resulting in extremely low cost, high safety, no risk of flammability or explosion, and no need for special storage conditions. When the gas is nitrogen, it is an inert gas with extremely stable chemical properties, does not react with any materials, avoids corrosion or contamination of the object being tested, has high safety, is non-flammable and non-toxic, and has a density close to that of air with moderate diffusivity. It is understood that other types of gases can also be used.

[0061] exist Figure 4 In the illustrated embodiment, step 10 determines the volume of the battery pack 3, including steps 11 to 13.

[0062] Step 11: Inject equal amounts of gas into the receiving cavity 21 and the battery pack 3, respectively. In some embodiments, the gas entering the receiving cavity 21 and the battery pack 3 can be measured by gas flow meters 23 between the gas source 22 and the receiving cavity 21, and between the gas source 22 and the battery pack 3, so that the amount of gas entering the receiving cavity 21 is the same as the amount of gas entering the battery pack 3.

[0063] Step 12: Obtain the temperature and pressure of the gas inside the containment cavity 21 and the gas inside the battery pack 3. It is understood that temperature and pressure sensors are installed inside both the containment cavity 21 and the battery pack 3. The temperature and pressure inside the containment cavity 21 and the battery pack 3 are detected using the temperature and pressure sensors installed in both locations.

[0064] Step 13: Determine the volume of the battery pack 3 based on the volume of the receiving cavity 21, the temperature and pressure of the gas in the receiving cavity 21, and the temperature and pressure of the gas in the battery pack 3.

[0065] Specifically, in step 13, the amount of gas can be calculated based on the ideal gas equation, the volume of the receiving cavity 21, and the temperature and pressure of the gas inside the receiving cavity 21. Since the amount of gas entering the receiving cavity 21 is the same as the amount of gas entering the battery pack 3, the volume of the battery pack 3 can be calculated based on the ideal gas equation, the amount of gas entering the battery pack 3, and the temperature and pressure of the gas inside the battery pack 3. This facilitates the determination of the volume of the battery pack 3 for subsequent airtightness testing.

[0066] Please refer to Figure 5 and Figure 6 , Figure 5 This is a schematic diagram of the structure of an airtightness detection system according to another embodiment of this application. Figure 6 for Figure 1 A flowchart illustrating another implementation of step 10 is shown. Figure 5 The illustrated embodiments and Figure 3 The illustrated embodiments are essentially the same. The difference lies in that... Figure 5 In the illustrated embodiment, the receiving cavity 21 and the battery pack 3 can be in communication. Figure 6 In the illustrated embodiment, step 10, determining the volume of the battery pack 3, includes steps 14 to 16.

[0067] Step 14: Inject gas into the receiving cavity 21 and obtain the temperature and pressure of the gas in the receiving cavity 21.

[0068] Step 15: Connect the receiving cavity 21 and the battery pack 3 to obtain the temperature and pressure of the gas inside the receiving cavity 21 and the battery pack 3. After connecting the receiving cavity 21 and the battery pack 3, the gas inside the receiving cavity 21 is dispersed within the receiving cavity 21 and the battery pack 3, and at this time, the amount of gas in the receiving cavity 21 and the battery pack 3 is the same as the amount of gas injected into the receiving cavity 21.

[0069] and Figure 4 Compared to the embodiments shown, Figure 5 In the illustrated embodiment, it is not necessary to strictly control the amount of gas entering the receiving cavity 21 to be exactly the same as the amount of gas entering the battery pack 3, thus avoiding the impact of different amounts of gas entering the receiving cavity 21 and the battery pack 3 on the volume calculation of the battery pack 3. Furthermore, a temperature sensor and a pressure sensor can be installed only within the receiving cavity 21. These sensors measure the temperature and pressure of the gas within the receiving cavity 21 when it is not connected to the battery pack 3, and measure the temperature and pressure of the gas within both the receiving cavity 21 and the battery pack 3 when they are connected.

[0070] Step 16: Determine the volume of the battery pack 3 based on the volume of the receiving cavity 21, the temperature and pressure of the gas in the receiving cavity 21 when the receiving cavity 21 and the battery pack 3 are not connected, and the temperature and pressure of the gas in the receiving cavity 21 and the battery pack 3 when the receiving cavity 21 and the battery pack 3 are connected.

[0071] Specifically, before the receiving cavity 21 and battery pack 3 are connected, the amount of substance of the gas can be calculated based on the ideal gas equation, the volume of the receiving cavity 21, and the temperature and pressure of the gas inside the receiving cavity 21. The total amount of substance remains unchanged before and after the receiving cavity 21 and battery pack 3 are connected. The total volume of the receiving cavity 21 and battery pack 3 is determined based on the ideal gas equation, the amount of substance, and the temperature and pressure of the gas inside the receiving cavity 21 and battery pack 3. The volume of battery pack 3 is obtained by subtracting the total volume of the receiving cavity 21 from the total volume of the receiving cavity 21 and battery pack 3.

[0072] Please refer to Figure 7 , Figure 7 This is a schematic flowchart of a battery pack airtightness testing method 1 according to another embodiment of this application. Figure 7 In the embodiment shown, after gas is injected into the battery pack 3 in step 20 until the gas pressure inside the battery pack 3 reaches a preset pressure, the detection method 1 further includes step 50.

[0073] Step 50: Within a first preset duration, control the battery pack 3 to maintain a preset pressure. In some specific embodiments, the first preset duration can be 2 minutes. The first preset duration is the pressure holding duration. Maintaining the preset pressure in the battery pack 3 within the pressure holding duration can stabilize the gas in the battery pack 3 and avoid the influence of fluctuations on the airtightness detection. Furthermore, by maintaining the pressure, if there is leakage in the battery pack 3, the leakage rate can be evened out, improving the accuracy of the measurement.

[0074] In step 30, the first pressure and first temperature of the gas inside the battery pack 3 at the first moment, and the second pressure and second temperature of the gas inside the battery pack 3 at the second moment are obtained. The first moment is the moment after the end of the first preset duration, and the time interval between the first moment and the end of the first preset duration is less than the second preset duration.

[0075] By setting the first moment to be the moment after the end of the first preset duration, and ensuring that the time interval between the first moment and the end of the first preset duration is less than the second preset duration, measurements are taken as soon as possible after the pressure holding period ends. This prevents excessive pressure drop caused by leakage in battery pack 3, ensuring that the airtightness test is not performed within the pressure range specified in the battery pack 3 testing procedure, thus affecting the accuracy of the test.

[0076] Please refer to Figure 8 , Figure 8This is a schematic flowchart of another embodiment of the airtightness testing method 1 of this application. The battery pack airtightness testing system 2 includes a receiving cavity 21. Figure 8 As shown, after determining the volume of the battery pack 3 in step 10, the detection method 1 further includes step 60.

[0077] Step 60: Connect the receiving cavity 21 and the battery pack 3.

[0078] Step 40 determines the leakage rate of battery pack 3 based on the first pressure, first temperature, second pressure, second temperature, volume of battery pack 3, and the duration between the second and first moments, including:

[0079] The leakage rate of battery pack 3 is determined based on the first pressure, first temperature, second pressure, second temperature, volume of battery pack 3, volume of receiving cavity 21, and the duration between the second moment and the first moment.

[0080] Thus, by connecting the receiving cavity 21 and the battery pack 3, during airtightness testing, the leakage of the battery pack 3 can be determined based on the changes in air pressure and temperature of the receiving cavity 21 and the battery pack 3 as a whole. The first pressure and first temperature at a first moment, and the second pressure and second temperature at a second moment can be detected by pressure and temperature sensors installed in the receiving cavity 21. Therefore, temperature and pressure sensors do not need to be installed inside the battery pack 3. Using the airtightness testing method 1 provided in this embodiment, airtightness testing can be performed on the battery pack 3 without temperature and pressure sensors, expanding the detection range of airtightness testing and avoiding the influence of malfunctions of the temperature and pressure sensors built into the battery pack 3 on the airtightness test results.

[0081] In some embodiments, after connecting the receiving cavity 21 and the battery pack 3, injecting gas into the battery pack 3 until the gas pressure inside the battery pack 3 reaches a preset pressure includes:

[0082] Obtain the pressure of the gas inside the receiving cavity 21;

[0083] If the pressure of the gas in the receiving cavity 21 is greater than the preset pressure, stop filling the receiving cavity 21 with gas.

[0084] This improves the intelligence of inflation and avoids over-inflation. In some specific embodiments, the airtightness detection system 2 includes an inflation switch disposed between the air source 22 and the receiving cavity. The airtightness detection system 2 also includes a controller connected to the pressure sensor and the inflation switch. The controller is used to control the inflation switch to disconnect when the pressure detected by the pressure sensor in the receiving cavity 21 exceeds a set threshold.

[0085] In some embodiments, after connecting the receiving cavity 21 and the battery pack 3, obtaining the first pressure and first temperature of the gas inside the battery pack 3 at a first moment, and the second pressure and second temperature of the gas inside the battery pack 3 at a second moment, includes:

[0086] The first pressure and first temperature of the gas in the containment cavity 21 at the first moment, and the second pressure and second temperature of the gas in the containment cavity 21 at the second moment are obtained.

[0087] In this way, the first pressure and first temperature at the first moment, and the second pressure and second temperature at the second moment can be detected by pressure sensors and temperature sensors installed in the receiving cavity 21. This not only reduces the number of pressure sensors and temperature sensors, saving costs, but also reduces the number of influencing factors on the airtightness test results when using the same pressure sensor and temperature sensor to test the airtightness of different battery packs 3, further improving the accuracy of the test results.

[0088] In other embodiments, the battery pack airtightness testing system 2 includes a receiving cavity 21, which is connected to the battery pack 3. A flow meter is provided between the receiving cavity 21 and the battery pack 3 to reflect the amount of gas transferred from the receiving cavity 21 into the battery pack 3. After step 20, gas is injected into the battery pack 3 until the gas pressure inside the battery pack 3 reaches a preset pressure, the testing method 1 further includes:

[0089] The amount of gas transferred from the containment cavity 21 to the battery pack 3 within a third preset time period is obtained.

[0090] The leakage rate of battery pack 3 is determined based on the transfer volume and the third preset duration.

[0091] Thus, when the receiving cavity 21 and the battery pack 3 are connected, if there is a gas leak in the battery pack 3, even a small leak, the pressure at both ends of the receiving cavity 21 and the battery pack 3 will gradually become unbalanced over time. Based on the law of conservation of mass, when there is a leak in the sealed system, in order to maintain internal pressure stability, the receiving cavity must continuously replenish the gas flow to the battery pack 3, and the replenished gas flow is essentially equivalent to the leakage amount.

[0092] Please refer to Figure 9 , Figure 9 This is a structural block diagram of an airtightness detection system 2 provided in one embodiment of this application. Figure 9 In the embodiment shown, the battery pack airtightness detection system includes a memory, a processor 51, and a program stored in the memory and executable on the processor. When the processor executes the program, it implements the battery pack airtightness detection method 1.

[0093] exist Figure 9In the illustrated embodiment, the airtightness control system 2 may include a computer-readable storage medium 52, which may store a program that can be invoked by a processor 51, and may include a non-volatile storage medium. In some embodiments, the airtightness control system 2 may include memory 53 and an interface 54. In some embodiments, the airtightness control system may also include other hardware depending on the actual application.

[0094] This application, in another aspect, provides a computer-readable storage medium on which a program is stored, which, when executed, implements a battery pack airtightness detection method 1. In some embodiments, the program may take the form of a computer program product implemented on one or more computer-readable storage media 52 (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing program code. The computer-readable storage medium 52 includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented using any method or technology. The information may be computer-readable instructions, data structures, program modules, or other data. Examples of computer-readable storage media 52 include, but are not limited to: phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, read-only optical disc read-only memory (CD-ROM), digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium, which can be used to store information accessible by a computing device.

[0095] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0096] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for detecting the airtightness of a battery pack, applied to a battery pack airtightness detection system, characterized in that, include: Determine the volume of the battery pack; Gas is injected into the battery pack until the gas pressure inside the battery pack reaches a preset pressure. The first pressure and first temperature of the gas inside the battery pack at a first moment, and the second pressure and second temperature of the gas inside the battery pack at a second moment are obtained. The leakage rate of the battery pack is determined based on the first pressure, the first temperature, the second pressure, the second temperature, the volume of the battery pack, and the duration between the second time and the first time.

2. The battery pack airtightness testing method according to claim 1, characterized in that, Determining the leakage rate of the battery pack based on the first pressure, the first temperature, the second pressure, the second temperature, the volume of the battery pack, and the duration between the second time and the first time includes: The first pressure at the first temperature is converted into a third pressure at the second temperature based on the volume of the battery pack; The leakage rate of the battery pack is determined based on the difference between the third pressure and the second pressure and the duration.

3. The battery pack airtightness testing method according to claim 1, characterized in that, The battery pack airtightness detection system includes a receiving cavity, and determining the volume of the battery pack includes: Gases of equal amounts are injected into the containment cavity and the battery pack, respectively. The temperature and pressure of the gas inside the containment cavity and the temperature and pressure of the gas inside the battery pack are obtained. The volume of the battery pack is determined based on the volume of the receiving cavity, the temperature and pressure of the gas inside the receiving cavity, and the temperature and pressure of the gas inside the battery pack.

4. The battery pack airtightness testing method according to claim 1, characterized in that, After the gas pressure inside the battery pack reaches a preset pressure through gas injection, the detection method further includes: Within a first preset duration, the battery pack is controlled to maintain the preset pressure; In the process of obtaining the first pressure and first temperature of the gas inside the battery pack at the first moment, and the second pressure and second temperature of the gas inside the battery pack at the second moment, the first moment is the moment after the end of the first preset duration, and the time interval between the first moment and the end of the first preset duration is less than the second preset duration.

5. The battery pack airtightness testing method according to claim 1, characterized in that, The battery pack airtightness testing system includes a receiving cavity, and after determining the volume of the battery pack, the testing method further includes: The cavity and the battery pack are connected. Determining the leakage rate of the battery pack based on the first pressure, the first temperature, the second pressure, the second temperature, the volume of the battery pack, and the duration between the second time and the first time includes: The leakage rate of the battery pack is determined based on the first pressure, the first temperature, the second pressure, the second temperature, the volume of the battery pack, the volume of the receiving cavity, and the duration between the second time and the first time.

6. The battery pack airtightness testing method according to claim 5, characterized in that, The step of injecting gas into the battery pack until the gas pressure inside the battery pack reaches a preset pressure includes: Obtain the pressure of the gas inside the containment cavity; If the pressure of the gas in the receiving cavity is greater than the preset pressure, the inflation of the receiving cavity will be suspended.

7. The battery pack airtightness testing method according to claim 5, characterized in that, The process of obtaining the first pressure and first temperature of the gas inside the battery pack at a first moment, and the second pressure and second temperature of the gas inside the battery pack at a second moment, includes: The first pressure and first temperature of the gas in the containment cavity at the first moment, and the second pressure and second temperature of the gas in the containment cavity at the second moment are obtained.

8. The battery pack airtightness testing method according to claim 1, characterized in that, The battery pack airtightness testing system includes a receiving cavity. After injecting gas into the battery pack until the gas pressure inside the battery pack reaches a preset pressure, the testing method further includes: The amount of gas transferred from the containment cavity to the battery pack within a third preset time period is obtained. The leakage rate of the battery pack is determined based on the transfer amount and the third preset duration.

9. A battery pack airtightness testing system, characterized in that, It includes a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor executes the program to implement the battery pack airtightness detection method as described in any one of claims 1-8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a program that, when executed, implements the battery pack airtightness detection method as described in any one of claims 1-8.

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