{"id":8458,"date":"2026-10-23T17:00:34","date_gmt":"2026-10-23T09:00:34","guid":{"rendered":"https:\/\/www.air-tester.com\/?p=8458"},"modified":"2026-10-24T13:43:11","modified_gmt":"2026-10-24T05:43:11","slug":"dong-li-dian-chi-qi-mi-xing","status":"publish","type":"post","link":"https:\/\/www.air-tester.com\/en\/dong-li-dian-chi-qi-mi-xing.html\/","title":{"rendered":"A Comprehensive Guide to Power Battery Leak Testing: National Standard Updates, Testing Methods, and Selection Guidelines"},"content":{"rendered":"

On July 1, 2026, GB 38031-2025 officially took effect, fully replacing the 2020 version.<\/strong> <\/p>\n\n\n\n

\"GB
GB 38031-2025 Safety Requirements for Power Batteries for Electric Vehicles<\/em><\/figcaption><\/figure>\n\n\n\n

What does this mean for power battery manufacturers? How have the type test requirements changed? How should you choose an air leak tester for your production line? This article provides direct answers.<\/p>\n\n\n\n

I. Several National Standards You Need to Know<\/h2>\n\n\n\n
(an official) standard<\/th>Main Functions<\/th>Relationship to Leak Testing<\/th><\/tr><\/thead>
GB 38031-2025<\/strong><\/td>Safety Requirements for Power Batteries Used in Electric Vehicles (Current Version)<\/td>Safety tests, including water immersion and wet-heat cycling, are core safety benchmarks.<\/td><\/tr>
GB\/T 4208-2017<\/td>Enclosure Protection Rating (IP Code)<\/td>Basic Standards for Understanding and Verifying the Dust and Water Resistance Ratings of Enclosures<\/td><\/tr>
GB\/T 30038-2013<\/td>Protection Ratings for Electrical and Electronic Equipment in Road Vehicles<\/td>IP Rating Evaluation for In-Vehicle Electrical Equipment<\/td><\/tr>
GB\/T 31467-2023<\/td>Test Methods for the Electrical Performance of Lithium-Ion Battery Packs<\/td>Primarily focuses on electrical performance; not a general standard for airtightness leakage rates<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

One thing must be made clear:The type test requirements of GB 38031-2025 cannot be directly applied to production lines.airtightness meter<\/a>Pressure values and leakage rate limits.<\/strong>\u00a0Production line parameters must be established separately in accordance with the product technical agreement, the automaker\u2019s acceptance criteria, and the specific IP rating targets.<\/p>\n\n\n\n

\"\u4e00\u6587\u770b\u61c2\u52a8\u529b\u7535\u6c60\u6c14\u5bc6\u6027\u68c0\u6d4b\u5168\u89e3\uff1a\u56fd\u6807\u66f4\u65b0\u3001\u68c0\u6d4b\u65b9\u6cd5\u4e0e\u9009\u578b\u6307\u5357\u63d2\u56fe1\"
GB\/T 48100-2026 Test Methods for In-Service Inspection of Electric Vehicle Power Batteries<\/em><\/figcaption><\/figure>\n\n\n\n

In addition, GB\/T 30038-2026 has been published and will take effect on March 1, 2027. When developing new projects, assess in advance how the revision of this standard will affect the validation plan.<\/p>\n\n\n\n

II. If the type test has been passed, why does the production line still need to be equipped with...airtightness meter<\/a>?<\/h2>\n\n\n\n

The answer is simple:Type testing proves that \u201cthis product is safe by design,\u201d while production line leak testing proves that \u201cthis product is actually leak-free.\u201d<\/strong> These are two completely different things.<\/p>\n\n\n\n

\"\u4e00\u6587\u770b\u61c2\u52a8\u529b\u7535\u6c60\u6c14\u5bc6\u6027\u68c0\u6d4b\u5168\u89e3\uff1a\u56fd\u6807\u66f4\u65b0\u3001\u68c0\u6d4b\u65b9\u6cd5\u4e0e\u9009\u578b\u6307\u5357\u63d2\u56fe2\"
Air Tightness Testing of Power Battery Packs<\/em><\/figcaption><\/figure>\n\n\n\n

The sealing structure of a power battery pack is extremely complex\u2014including the sealing gaskets between the top cover and bottom housing, the locations where high- and low-voltage connectors pass through the compartment, the cooling line connections and weld seams, the installation areas for the waterproof and breathable membrane, and the mating surfaces of die-cast parts and bolts. If a sealing defect occurs at any one of these points, the protection rating of the entire pack will be compromised. Yet visual inspections cannot detect even the slightest leak.<\/p>\n\n\n\n

Replace subjective judgments like \u201cit looks fine\u201d with quantifiable data<\/strong>...This is the fundamental reason for conducting airtightness testing on production lines.<\/p>\n\n\n\n

III. Four Testing Methods: Which One Should You Choose?<\/h2>\n\n\n\n

The key to selecting the right model lies not only in the instrument\u2019s accuracy, but also in a comprehensive evaluation of the product\u2019s volume, structural rigidity, target leak rate, production cycle time, and cost.<\/p>\n\n\n\n

Direct-Pressure Leak Test<\/h3>\n\n\n\n

Apply a set pressure to the workpiece and monitor pressure changes after a stabilization period. This method has the simplest structure and is suitable for battery casings, sealing covers, various fasteners, and workpieces with larger volumes.Key Considerations for Selection<\/strong>: Test volume, elastic deformation of the workpiece, equilibration time, and allowable leakage rate.<\/p>\n\n\n\n

Differential Pressure Leak Testing<\/h3>\n\n\n\n

The test piece and the reference chamber are pressurized simultaneously, and leaks are detected by comparing the pressure difference between the two sides. This effectively compensates for common-mode fluctuations caused by factors such as temperature,Higher repeatability<\/strong>, suitable for precision components with strict sealing requirements.Key Considerations for Selection<\/strong>: Reference chamber matching, temperature stabilization time, and sensor performance.<\/p>\n\n\n\n

Flow-Based Detection<\/h3>\n\n\n\n

This method quantitatively evaluates leaks by measuring the gas flow rate passing through the leak point per unit of time, making it suitable for scenarios where product standards need to be established in units of mL\/min or sccm.Key Considerations for Selection<\/strong>: Flow range, test pressure, unit conversion method.<\/p>\n\n\n\n

Helium Mass Spectrometry Leak Detection<\/h3>\n\n\n\n

Using helium as a tracer gas provides significantly higher sensitivity than air detection and is suitable for R&D validation or specific high-reliability applications.Due to high consumable costs and slow inspection cycles, this approach is not typically the first choice for mass production scenarios.<\/strong><\/p>\n\n\n\n

These four methods are not ranked in order of increasing accuracy; rather, they each have their own specific focus depending on the product and application. For mass-production leak screening, an appropriate air-tightness solution is easier to integrate into the production line; helium testing is only necessary for verifying extreme micro-leaks. Both methods can be used in conjunction within the same quality system.<\/p>\n\n\n\n

IV. Which Equipment Should You Choose for Different Components?<\/h2>\n\n\n\n
target of detection<\/th>Focus on Defects<\/th>Equipment Selection Recommendations<\/th><\/tr><\/thead>
Battery Pack Top Cover, Lower Housing<\/td>Failed sealing strips, cracks in the housing, and leaks at welds<\/td>Direct-Pressure or Differential-Pressure<\/td><\/tr>
Battery Pack Assembly<\/td>Leaks across multiple sealing surfaces, connectors, and interfaces<\/td>Select between direct-pressure and differential-pressure types based on volume and target leak rate<\/td><\/tr>
Liquid-cooled plates, cooling lines, quick-connect fittings<\/td>Welding sand holes, poor joint sealing, and pipeline leaks<\/td>Differential-pressure, direct-pressure, or flow-based<\/td><\/tr>
waterproof and breathable membrane<\/td>Abnormal air permeability, insufficient water-blocking capacity<\/td>Combined Air Permeability and Water Pressure Resistance Testing Equipment<\/td><\/tr>
High-Reliability Seals and R&D Prototypes<\/td>Extremely low leakage rates or specific failure mechanisms<\/td>Methods Such as Helium Mass Spectrometry Based on Target Leak Rate Assessment<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Large Thin-Walled Shells<\/strong>There is one pitfall that\u2019s easy to overlook:Elastic deformation during inflation introduces noise into the pressure data<\/strong>. Not enough time to balance things out,Material Expansion<\/strong>The resulting pressure fluctuations could be mistaken for a leak. When selecting equipment, one should not rely solely on sensor resolution; it is essential to run the entire process using actual workpieces and conduct continuous, repeatable tests.<\/p>\n\n\n\n

V. What Does Jingcheng Engineering Offer?<\/h2>\n\n\n\n

Jingcheng Engineering (JCGK) isShenzhen Jingchenggongke Technology Co., Ltd.<\/a>A proprietary brand specializing in airtightness testing, coveringAirtightness Tester<\/a>,Waterproof Tester<\/a>,Non-standard automation equipment<\/a>, supporting tooling and automation integration.<\/p>\n\n\n\n

The logic behind the JCGK solution is as follows:First, confirm the product requirements; then, select the testing method and fixtures; finally, use actual samples to verify whether the requirements can be met for mass production.<\/strong> We don\u2019t just sell equipment; we provide practical, end-to-end solutions tailored to product structure, production line rhythms, and data traceability requirements.<\/p>\n\n\n\n

Dual-station or multi-channel inspection<\/strong>: For similar structural components such as top covers and bottom housings, we design dedicated workstations and matching fixtures; the use of multiple parallel channels significantly reduces wait times.<\/p>\n\n\n\n