Gamingdeputy reported on May 6 that in order to further improve the quality and safety level of lithium-ion batteries for electric bicycles and promote the safe and healthy development of the industry, the Ministry of Industry and Information Technology was responsible for drafting the “Safety technical specifications for lithium-ion batteries for electric bicycles“(GB 43854-2024, hereinafter referred to as “Technical Specifications”) mandatory national standard was officially released by the State Administration for Market Regulation (National Standards Administration) recently.
The announcement stated that at present, electric bicycles have become an important means of transportation in consumers' daily lives. my country is not only a major producer of electric bicycles, but also a major user of electric bicycles. At present, the number of electric bicycles in my country has exceeded 350 million. In 2023, enterprises above designated size nationwide will produce a total of 42.28 million electric bicycles. There are two main types of batteries used in electric bicycles: lead batteries and lithium-ion batteries. Among the new electric bicycle models released by major domestic electric bicycle brands,The proportion equipped with lithium-ion batteries has exceeded 20%.
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The “Technical Specifications” stipulates the safety requirements and test methods for lithium batteries for electric bicycles that are applicable to the “Technical Specifications for Safety of Electric Bicycles” (GB 17761) from both the single cell and battery pack levels.Will be officially implemented on November 1, 2024. Among them, the single battery mainly considers six safety requirements: overcharge, over-discharge, external short circuit, thermal abuse, acupuncture, and marking; the battery pack mainly considers electrical safety, mechanical safety, environmental safety, thermal diffusion, and mutual recognition collaborative charging. 22 safety requirements in 7 aspects including data collection, marking, etc.
The Ministry of Industry and Information Technology stated that the “Technical Specifications”, as a mandatory national standard for the safety of lithium-ion batteries for electric bicycles, is of great significance for regulating the design, production and sales of lithium-ion battery products for electric bicycles, improving product quality and safety levels, and will promote the health of the electric bicycle industry orderly development.
In the next step, the Ministry of Industry and Information Technology will work with relevant departments to systematically organize and carry out publicity and implementation training on the “Technical Specifications” for electric bicycle and lithium-ion battery manufacturers and related dealers. At the same time, the Ministry of Industry and Information Technology will intensify the implementation of standards to guide and supervise relevant production enterprises. Strictly produce in accordance with the requirements of the “Technical Specifications” to promote the effective implementation of mandatory national standards and ensure safe and reliable product quality.
Gamingdeputy notes that the “Technical Specifications” only apply to the maximum output voltage specified in GB 17761 “Safety Technical Specifications for Electric Bicycles”Lithium-ion batteries for electric bicycles not exceeding 60V. Not suitable for lithium-ion batteries used in electric scooters, balance scooters, electric motorcycles, electric tricycles and other vehicles.
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Common lithium-ion batteries for electric bicycles mainly include lithium manganate batteries, lithium iron phosphate batteries and ternary lithium batteries. Among them, ternary lithium batteries can be divided into high-nickel system nickel-cobalt-manganese batteries, nickel-cobalt-aluminum batteries, and nickel-free lithium manganese iron phosphate batteries.
The “Technical Specifications” stipulates strict overcharge (1.5 times), acupuncture and other tests for single batteries.It is difficult for high-nickel system ternary lithium batteries to pass the above tests and will be difficult to be used in the field of electric bicycles in the future..
The “Technical Specifications” stipulates 6 test items for single cells, including marking, overcharge, over-discharge, external short circuit, thermal abuse, and needle puncture; 22 test items for battery packs, including marking, electrostatic discharge, over-discharge, Overcharging, temperature protection, external short circuit, mutual recognition cooperative charging, data collection, insulation resistance, extrusion, acceleration impact, vibration, free fall, handle strength, flame retardancy, low pressure, overcurrent discharge, temperature cycle, water immersion , salt spray, heat and humidity cycle, heat diffusion.
Among them, the following test items need to be focused on:
1. Single battery overcharge (1.5 times) test and acupuncture test can effectively screen the safety of the battery.
2. The battery pack should have a unique code, and the code mark needs to be made of high-temperature resistant (950°C) material, so that it can be traced even if a fire occurs.
3． The overcharge, external short circuit, and overcurrent discharge tests of the battery pack must be conducted under normal operating conditions and under single fault conditions of the protection components. Therefore, the battery pack may need to adopt a dual protection design to meet the requirements.
4. The battery pack needs to have the function of mutual recognition and collaborative charging to reduce the risk of mismatched charging devices for charging the battery pack.
5. During the charging and discharging process of the battery pack, the battery voltage, battery pack voltage/temperature/current should be collected in real time, which requires the battery pack to be equipped with a management system (intelligent “brain”) for real-time monitoring.
6. Manufacturers should clearly indicate the “safe service life” on the battery pack to remind users to eliminate old batteries in time. This is because as the service life of lithium-ion batteries increases, their safety risks will gradually increase.
7. The casing, printed circuit board, and wires of the battery pack should be made of flame-retardant materials to reduce the spread of flames after a fire occurs.
8. The thermal diffusion test of the battery pack requires that when a single cell in the battery pack catches fire, it must not spread quickly to the entire battery pack.