Hydrogen-nitrogen battery pack leak detection system and leak detection method thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DONGGUAN HAIRUISI MEASUREMENT & CONTROL TECH CO LTD
- Filing Date
- 2026-04-13
- Publication Date
- 2026-06-09
Smart Images
Figure CN122171128A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of airtightness testing technology, and in particular to a leak detection system and method for hydrogen-nitrogen battery packs. Background Technology
[0002] The electrolyte inside the battery pack is highly corrosive, flammable, and explosive. If the battery pack is not properly sealed, electrolyte leakage can severely impact battery performance and lifespan, and may even cause short circuits, fires, or explosions – extremely dangerous situations. Those skilled in the art must continuously seek better solutions for more precise, accurate, and user-friendly leak detection of battery packs.
[0003] In existing technologies, helium is typically used as a tracer gas. Helium is introduced into the battery cell, and if there is a leak in the battery pack, helium will escape from the leak. The location and size of the leak can be determined by detecting the change in helium concentration using a specific helium sensor.
[0004] When the aforementioned method of using helium as a tracer gas to detect battery pack leaks is applied to real-world scenarios, it faces several challenges. Firstly, helium is expensive, making the leak detection process costly. Secondly, to ensure detection accuracy, the concentration of helium inside the battery pack needs to be maximized. Existing technologies often involve first evacuating the battery pack to remove other gases that might affect the detection results before filling it with helium to complete the detection. During this process, the internal pressure of the battery pack will undergo a rapid change from vacuum to helium-filled. However, the battery pack's structure inherently limits its pressure resistance, and the pressure change from vacuum to a specified pressure will damage the battery pack's structure, affecting its performance.
[0005] Therefore, improving the leak detection method for battery packs and finding a high-precision leak detection method that causes less damage to the battery pack structure is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0006] The purpose of this invention is to provide a leak detection system for hydrogen-nitrogen battery packs. This system can adapt to the poor pressure resistance of battery packs, minimize the damage to the battery pack structure during the leak detection process, and achieve high leak detection accuracy.
[0007] To achieve the above objectives, the present invention provides the following technical solution:
[0008] A leak detection system for a hydrogen-nitrogen battery pack includes a valve island, a general gas source, a hydrogen-nitrogen gas source, a negative pressure source, and a hydrogen gas detector.
[0009] The ordinary gas source, the hydrogen-nitrogen gas source, and the negative pressure source are respectively connected to the valve island, and the valve island is also detachably connected to the battery pack to be tested;
[0010] The hydrogen probe is movably positioned near the outer surface of the battery pack.
[0011] Optionally, the valve island includes a charge / discharge valve and a single-port standard leak; the input end of the charge / discharge valve is connected to the ordinary gas source, the hydrogen / nitrogen gas source, or the negative pressure source, and the output end of the charge / discharge valve is connected to the battery pack under test; the single-port standard leak is disposed on the pipeline connecting the charge / discharge valve and the battery pack under test, and the single-port standard leak is connected to the battery pack under test.
[0012] Optionally, the valve island includes an inflation valve, a deflation valve, and a multi-port standard leak; the input end of the inflation valve is connected to the ordinary gas source or the hydrogen / nitrogen gas source, and the output end of the inflation valve is connected to one of the test ports of the battery pack under test; the input end of the deflation valve is connected to the other test port of the battery pack under test, and the output end of the deflation valve is connected to the negative pressure source; the multi-port standard leak is disposed on the pipeline connecting the deflation valve and the battery pack under test, and the multi-port standard leak is connected to the battery pack under test.
[0013] This invention also provides a method for leak detection of a hydrogen-nitrogen battery pack, the method being based on the hydrogen-nitrogen battery pack leak detection system described above, comprising:
[0014] S1. Ventilation: Introduce ordinary gas into the battery pack under test until the internal pressure reaches the preset low-pressure inflation threshold.
[0015] S2. Coarse screening: Seal the battery pack and monitor the internal pressure changes to determine if there are large-diameter leaks in the battery pack. If there are large-diameter leaks in the current battery pack, discard the battery pack; otherwise, jump to S3.
[0016] S3. Ventilation: Introduce a hydrogen-nitrogen mixture into the battery pack to expel the ordinary gas inside the battery pack, so that the internal pressure of the battery pack can return to the preset low-pressure inflation threshold.
[0017] S4. Fine inspection: Monitor the escape of hydrogen-nitrogen mixture from the outside of the battery pack.
[0018] Optionally, S1, ventilation, specifically refers to:
[0019] A low-pressure inflation threshold is preset; the valve island connects the ordinary gas source to the battery pack under test, and ordinary gas is introduced into the battery pack under test; the real-time pressure inside the battery pack is continuously monitored, and when the gas pressure inside the battery pack reaches the low-pressure inflation threshold, the valve island cuts off the connection between the ordinary gas source and the battery pack.
[0020] Optionally, step S2, the coarse screening, includes the following sub-steps:
[0021] S21. Preset pressure holding time and pressure holding threshold;
[0022] S22. The valve island is closed, sealing the battery pack;
[0023] S23. During the pressure holding time, continuously monitor the pressure change of the battery pack. If the internal pressure change of the battery pack exceeds the pressure holding threshold, it is determined that the current battery pack has a large-diameter leak and the battery pack is discarded; otherwise, jump to S3.
[0024] Optionally, step S3, ventilation, includes the following sub-steps:
[0025] S31. Preset threshold for the number of air exchange wheels per port and threshold for the inflation time per port;
[0026] S32. The charging / discharging valve connects the hydrogen-nitrogen gas source to the battery pack, and introduces a small amount of hydrogen-nitrogen mixed gas into the battery pack.
[0027] S33. The charging / discharging valve cuts off the connection with the hydrogen-nitrogen gas source and connects the negative pressure source with the battery pack, extracting a small amount of ordinary gas and hydrogen-nitrogen mixture from the battery pack.
[0028] S34. Compare the cumulative number of times the hydrogen-nitrogen mixture is filled with the threshold number of single-port gas exchangers. If the cumulative number of times the hydrogen-nitrogen mixture is filled with the gas does not exceed the threshold number of single-port gas exchangers, return to S32; otherwise, jump to S35.
[0029] Alternatively, compare the cumulative inflation time of the hydrogen-nitrogen mixture with the single-port inflation time threshold. If the cumulative inflation time of the hydrogen-nitrogen mixture does not exceed the single-port inflation time threshold, return to S32; otherwise, jump to S35.
[0030] S35: Calibrate the hydrogen probe using the single-port standard leak.
[0031] Optionally, step S3, ventilation, includes the following sub-steps:
[0032] S31. Preset multi-port air exchange pressure difference threshold and multi-port inflation time threshold;
[0033] S32. The inflation valve connects the hydrogen-nitrogen gas source to the battery pack, and the deflation valve connects the negative pressure source to the battery pack.
[0034] S33. Monitor the internal pressure change of the battery pack. If the internal pressure change of the battery pack exceeds the multi-port ventilation pressure difference threshold, adjust the opening ratio of the inflation valve and the deflation valve; otherwise, proceed to S34.
[0035] S34. Compare the opening time of the inflation valve with the multi-port inflation duration threshold. If the opening time of the inflation valve does not exceed the multi-port inflation duration threshold, return to S32; otherwise, jump to S35.
[0036] S35. Calibrate the hydrogen probe using the multi-port standard leak.
[0037] Optionally, S4, fine inspection specifically involves: the probe moving close to the battery pack and along the outer surface of the battery pack to monitor the hydrogen escaping from the outside of the battery pack.
[0038] Optional, also includes:
[0039] S5. Exhausting: The valve island connects the negative pressure source and the battery pack, squeezing out all the hydrogen gas inside, and disconnecting the battery pack that has completed the test from the valve island.
[0040] The beneficial effects of this invention are as follows:
[0041] Reduced damage to the battery pack structure during leak detection: In this invention, there is no need to evacuate the battery pack. By using low-pressure gas filling and a hydrogen-nitrogen mixture instead of the traditional helium gas detection method, the damage to the battery pack structure caused by drastic changes in internal gas pressure is effectively avoided.
[0042] Increasing the hydrogen concentration inside the battery pack improves leak detection accuracy: By using a hydrogen-nitrogen mixture as the tracer gas and combining it with a multi-stage detection process, the damage to the battery pack structure caused by high pressure differentials in traditional helium leak detection methods is effectively avoided. Simultaneously, calibrating the hydrogen detector using single-port or multi-port standard leak holes further enhances the accuracy and reliability of the detection. Furthermore, this invention achieves precise control of the gas inside the battery pack by setting up charging / discharging valves and flexibly switching between them, ensuring leak detection is completed within a lower pressure range, thereby significantly reducing the requirements for the battery pack's own pressure resistance. This design not only simplifies the operation process but also significantly reduces detection costs, providing a completely new solution for efficient and safe battery pack testing.
[0043] Low cost and easy to widely apply: This invention significantly reduces gas usage costs in the leak detection process by using a hydrogen-nitrogen mixture instead of traditional helium as the tracer gas. Simultaneously, the system structure is simple, and the connections and operating procedures between components have been optimized, making the overall device easy to manufacture and maintain. Furthermore, this leak detection method is applicable to the testing of various battery pack specifications, exhibiting strong versatility and adaptability, facilitating its application in different production environments. Through the refined design of the detection steps, not only is detection efficiency improved, but the detection cycle for a single battery pack is also significantly shortened, laying a solid foundation for large-scale industrial application. Attached Figure Description
[0044] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings, wherein:
[0045] Figure 1 This is a system block diagram of the single-port hydrogen-nitrogen battery pack leak detection system provided in Specific Implementation Method 1.
[0046] Figure 2 This is a flowchart of a leak detection method for a single-port hydrogen-nitrogen battery pack provided in Specific Implementation Method 1.
[0047] Figure 3 This is a system block diagram of the dual-port hydrogen-nitrogen battery pack leak detection system provided in Specific Implementation Method 2. Detailed Implementation
[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0049] Specific Implementation Method 1: Leak Detection System and Method for Single-Port Hydrogen-Nitrogen Battery Packs
[0050] Please see Figure 1-2 This specific embodiment provides a single-port hydrogen-nitrogen battery pack leak detection system and method for leak detection of battery packs with only one test port.
[0051] Specifically, in this embodiment, the single-port hydrogen-nitrogen battery pack leak detection system includes a valve island, a general gas source, a hydrogen-nitrogen gas source, a negative pressure source, and a hydrogen probe.
[0052] Ordinary gas source, hydrogen-nitrogen gas source and negative pressure source are respectively connected to the valve island, and the valve island is also detachably connected to the battery pack under test;
[0053] The hydrogen probe is movably positioned near the outer surface of the battery pack.
[0054] In this specific embodiment, the valve island includes a charge / discharge valve and a single-port standard leak; the input end of the charge / discharge valve is connected to a normal gas source, a hydrogen / nitrogen gas source, or a negative pressure source, and the output end of the charge / discharge valve is connected to the battery pack under test; the single-port standard leak is disposed on the pipeline connecting the charge / discharge valve and the battery pack under test, and the single-port standard leak is connected to the battery pack under test.
[0055] In this specific embodiment, a method for detecting leaks in a hydrogen-nitrogen battery pack is also provided. This method is based on the hydrogen-nitrogen battery pack leak detection system described above and includes:
[0056] S1. Ventilation: Introduce ordinary gas into the battery pack under test until the internal pressure reaches the preset low-pressure inflation threshold.
[0057] S2. Coarse screening: Seal the battery pack and monitor the internal pressure changes to determine if there are large-diameter leaks in the battery pack. If there are large-diameter leaks in the current battery pack, discard the battery pack; otherwise, jump to S3.
[0058] S3. Ventilation: Introduce a hydrogen-nitrogen mixture into the battery pack, displacing the ordinary gas inside the battery pack, so that the internal air pressure of the battery pack returns to the preset low-pressure inflation threshold.
[0059] S4. Fine inspection: Monitor the escape of hydrogen-nitrogen mixture from the outside of the battery pack.
[0060] In this specific embodiment, the above-mentioned leak detection method for hydrogen-nitrogen battery pack is as follows:
[0061] S11, Preset low-pressure inflation threshold;
[0062] S12, the valve island connects the ordinary gas source to the battery pack under test, and ordinary gas is introduced into the battery pack under test;
[0063] S13. Continuously monitor the real-time pressure inside the battery pack. When the air pressure inside the battery pack reaches the low-pressure inflation threshold, the valve island cuts off the connection between the ordinary air source and the battery pack.
[0064] S21. Preset pressure holding time and pressure holding threshold;
[0065] S22, Valve island closed, sealing the battery pack;
[0066] S23. During the pressure holding time, continuously monitor the pressure change of the battery pack. If the internal pressure change of the battery pack exceeds the pressure holding threshold, it is determined that the current battery pack has a large-diameter leak and the battery pack is discarded; otherwise, jump to S31.
[0067] S31. Preset threshold for the number of air exchange wheels per port and threshold for the inflation time per port;
[0068] S32, The charging / discharging valve connects the hydrogen-nitrogen gas source to the battery pack, allowing a small amount of hydrogen-nitrogen mixture to be introduced into the battery pack;
[0069] S33. The charging and discharging valve cuts off the connection with the hydrogen and nitrogen gas source, connects the negative pressure source to the battery pack, and extracts a small amount of mixed gas of ordinary gas and hydrogen and nitrogen gas from the battery pack.
[0070] S34. Compare the cumulative number of times the hydrogen-nitrogen mixture is charged with the threshold number of single-port gas exchangers. If the cumulative number of times the hydrogen-nitrogen mixture is charged does not exceed the threshold number of single-port gas exchangers, return to S32; otherwise, jump to S35.
[0071] Alternatively, compare the cumulative charging time of the hydrogen-nitrogen mixture with the single-port charging time threshold. If the cumulative charging time of the hydrogen-nitrogen mixture does not exceed the single-port charging time threshold, return to S32; otherwise, jump to S35.
[0072] S35: Use a single-port standard leak calibrator to calibrate the hydrogen detector.
[0073] S4. The probe moves close to the battery pack and along the outer surface of the battery pack to inspect and monitor the hydrogen escaping from the outside of the battery pack.
[0074] S5. The charging / discharging valve connects the negative pressure source to the battery pack, extracts all the hydrogen gas inside, and disconnects the battery pack that has completed the test from the valve island.
[0075] Specific Implementation Method Two: Dual-Port Hydrogen-Nitrogen Battery Pack Leak Detection System and Leak Detection Method
[0076] Please see Figure 3 This specific embodiment provides a dual-port hydrogen-nitrogen battery pack leak detection system and method for leak detection of battery packs with two test ports.
[0077] Specifically, in this embodiment, the dual-port hydrogen-nitrogen battery pack leak detection system includes a valve island, a general gas source, a hydrogen-nitrogen gas source, a negative pressure source, and a hydrogen probe.
[0078] Ordinary gas source, hydrogen-nitrogen gas source and negative pressure source are respectively connected to the valve island, and the valve island is also detachably connected to the battery pack under test;
[0079] The hydrogen probe is movably positioned near the outer surface of the battery pack.
[0080] In this specific embodiment, the valve island includes an inflation valve, a deflation valve, and a multi-port standard leak. The input end of the inflation valve is connected to a common gas source or a hydrogen / nitrogen gas source, and the output end of the inflation valve is connected to one of the test ports of the battery pack under test. The input end of the deflation valve is connected to the other test port of the battery pack under test, and the output end of the deflation valve is connected to a negative pressure source. The multi-port standard leak is disposed on the pipeline connecting the deflation valve and the battery pack under test, and the multi-port standard leak is connected to the battery pack under test.
[0081] This specific embodiment also provides a method for leak detection of a hydrogen-nitrogen battery pack. The method is based on the hydrogen-nitrogen battery pack leak detection system described above and includes:
[0082] S1. Ventilation: Introduce ordinary gas into the battery pack under test until the internal pressure reaches the preset low-pressure inflation threshold.
[0083] S2. Coarse screening: Seal the battery pack and monitor the internal pressure changes to determine if there are large-diameter leaks in the battery pack. If there are large-diameter leaks in the current battery pack, discard the battery pack; otherwise, jump to S3.
[0084] S3. Ventilation: Introduce a hydrogen-nitrogen mixture into the battery pack to expel the ordinary gas inside the battery pack, so that the internal pressure of the battery pack can return to the preset low-pressure inflation threshold.
[0085] S4. Fine inspection: Monitor the escape of hydrogen-nitrogen mixture from the outside of the battery pack.
[0086] In this specific embodiment, the above-mentioned leak detection method for hydrogen-nitrogen battery pack is as follows:
[0087] S11, Preset low-pressure inflation threshold;
[0088] S12, the valve island connects the ordinary gas source to the battery pack under test, and ordinary gas is introduced into the battery pack under test;
[0089] S13. Continuously monitor the real-time pressure inside the battery pack. When the air pressure inside the battery pack reaches the low-pressure inflation threshold, the valve island cuts off the connection between the ordinary air source and the battery pack.
[0090] S21. Preset pressure holding time and pressure holding threshold;
[0091] S22, Valve island closed, sealing the battery pack;
[0092] S23. During the pressure holding time, continuously monitor the pressure change of the battery pack. If the internal pressure change of the battery pack exceeds the pressure holding threshold, it is determined that the current battery pack has a large-diameter leak and the battery pack is discarded; otherwise, jump to S31.
[0093] S31. Preset multi-port air exchange pressure difference threshold and multi-port inflation time threshold;
[0094] S32. The inflation valve connects the hydrogen and nitrogen gas source to the battery pack, while the deflation valve connects the negative pressure source to the battery pack.
[0095] S33. Monitor the internal pressure change of the battery pack. If the internal pressure change of the battery pack exceeds the multi-port ventilation pressure difference threshold, adjust the opening ratio of the inflation valve and the deflation valve; otherwise, jump to S34.
[0096] S34. Compare the opening time of the inflation valve with the multi-port inflation time threshold. If the opening time of the inflation valve does not exceed the multi-port inflation time threshold, return to S32; otherwise, jump to S35.
[0097] S35. Use a multi-port standard leak calibrator to calibrate the hydrogen detector.
[0098] S4. The probe moves close to the battery pack and along the outer surface of the battery pack to inspect and monitor the hydrogen escaping from the outside of the battery pack.
[0099] S5. The charging / discharging valve connects the negative pressure source to the battery pack, extracts all the hydrogen gas inside, and disconnects the battery pack that has completed the test from the valve island.
[0100] The uninterruptible power supply disclosed in the embodiments of the present invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for helping to understand the technical solutions and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.
Claims
1. A leak detection system for a hydrogen-nitrogen battery pack, characterized in that, Includes valve island, ordinary gas source, hydrogen and nitrogen gas source, negative pressure source and hydrogen probe; The ordinary gas source, the hydrogen-nitrogen gas source, and the negative pressure source are respectively connected to the valve island, and the valve island is also detachably connected to the battery pack to be tested; The hydrogen probe is movably positioned near the outer surface of the battery pack.
2. The hydrogen-nitrogen battery pack leak detection system as described in claim 1, characterized in that, The valve island includes a charge / discharge valve and a single-port standard leak; the input end of the charge / discharge valve is connected to the ordinary gas source, the hydrogen / nitrogen gas source, or the negative pressure source, and the output end of the charge / discharge valve is connected to the battery pack under test; the single-port standard leak is disposed on the pipeline connecting the charge / discharge valve and the battery pack under test, and the single-port standard leak is connected to the battery pack under test.
3. The hydrogen-nitrogen battery pack leak detection system as described in claim 1, characterized in that, The valve island includes an inflation valve, a deflation valve, and a multi-port standard leak. The input end of the inflation valve is connected to the ordinary gas source or the hydrogen / nitrogen gas source, and the output end of the inflation valve is connected to one of the test ports of the battery pack under test. The input end of the deflation valve is connected to the other test port of the battery pack under test, and the output end of the deflation valve is connected to the negative pressure source. The multi-port standard leak is located on the pipeline connecting the deflation valve and the battery pack under test, and the multi-port standard leak is connected and communicated with the battery pack under test.
4. A method for leak detection of a hydrogen-nitrogen battery pack, said method being based on the hydrogen-nitrogen battery pack leak detection system as described in any one of claims 1-3, characterized in that, include: S1. Ventilation: Introduce ordinary gas into the battery pack under test until the internal pressure reaches the preset low-pressure inflation threshold. S2. Coarse screening: Seal the battery pack and monitor the internal pressure changes to determine if there are large-diameter leaks in the battery pack. If there are large-diameter leaks in the current battery pack, discard the battery pack; otherwise, jump to S3. S3. Ventilation: Introduce a hydrogen-nitrogen mixture into the battery pack to expel the ordinary gas inside the battery pack, so that the internal pressure of the battery pack can return to the preset low-pressure inflation threshold. S4. Fine inspection: Monitor the escape of hydrogen-nitrogen mixture from the outside of the battery pack.
5. The method for leak detection of a hydrogen-nitrogen battery pack as described in claim 4, characterized in that, S1, ventilation, specifically refers to: A low-pressure inflation threshold is preset; the valve island connects the ordinary gas source to the battery pack under test, and ordinary gas is introduced into the battery pack under test; the real-time pressure inside the battery pack is continuously monitored, and when the gas pressure inside the battery pack reaches the low-pressure inflation threshold, the valve island cuts off the connection between the ordinary gas source and the battery pack.
6. The method for leak detection of a hydrogen-nitrogen battery pack as described in claim 5, characterized in that, S2, the coarse screening, includes the following sub-steps: S21. Preset pressure holding time and pressure holding threshold; S22. The valve island is closed, sealing the battery pack; S23. During the pressure holding time, continuously monitor the pressure change of the battery pack. If the internal pressure change of the battery pack exceeds the pressure holding threshold, it is determined that the current battery pack has a large-diameter leak and the battery pack is discarded; otherwise, jump to S3.
7. The method for leak detection of a hydrogen-nitrogen battery pack as described in claim 6, characterized in that, S3, ventilation, includes the following sub-steps: S31. Preset threshold for the number of air exchange wheels per port and threshold for the inflation time per port; S32. The charging / discharging valve connects the hydrogen-nitrogen gas source to the battery pack, and introduces a small amount of hydrogen-nitrogen mixed gas into the battery pack. S33. The charging and discharging valve cuts off the connection with the hydrogen and nitrogen gas source, connects the negative pressure source with the battery pack, and extracts a small amount of mixed gas of ordinary gas and hydrogen and nitrogen gas from the battery pack. S34. Compare the cumulative number of times the hydrogen-nitrogen mixture is filled with the threshold number of single-port gas exchangers. If the cumulative number of times the hydrogen-nitrogen mixture is filled with the gas does not exceed the threshold number of single-port gas exchangers, return to S32; otherwise, jump to S35. Alternatively, compare the cumulative inflation time of the hydrogen-nitrogen mixture with the single-port inflation time threshold. If the cumulative inflation time of the hydrogen-nitrogen mixture does not exceed the single-port inflation time threshold, return to S32; otherwise, jump to S35. S35: Calibrate the hydrogen probe using the single-port standard leak.
8. The method for leak detection of a hydrogen-nitrogen battery pack as described in claim 6, characterized in that, S3, ventilation, includes the following sub-steps: S31. Preset multi-port air exchange pressure difference threshold and multi-port inflation time threshold; S32. The inflation valve connects the hydrogen-nitrogen gas source to the battery pack, and the deflation valve connects the negative pressure source to the battery pack. S33. Monitor the internal pressure change of the battery pack. If the internal pressure change of the battery pack exceeds the multi-port ventilation pressure difference threshold, adjust the opening ratio of the inflation valve and the deflation valve; otherwise, proceed to S34. S34. Compare the opening time of the inflation valve with the multi-port inflation duration threshold. If the opening time of the inflation valve does not exceed the multi-port inflation duration threshold, return to S32; otherwise, jump to S35. S35. Calibrate the hydrogen probe using the multi-port standard leak.
9. The method for leak detection of a hydrogen-nitrogen battery pack as described in claim 6, characterized in that, S4, fine inspection, specifically involves the probe moving close to the battery pack and along its outer surface to monitor the hydrogen escaping from the outside of the battery pack.
10. The method for leak detection of a hydrogen-nitrogen battery pack as described in claim 9, characterized in that, Also includes: S5. Exhausting: The valve island connects the negative pressure source and the battery pack, squeezing out all the hydrogen gas inside, and disconnecting the battery pack that has completed the test from the valve island.