Click to follow Liaoning Fire 2024-05-13 Liaoning
Recently, the mandatory national standard of "Safety Technical Specification for Lithium-ion Batteries for Electric Bicycles" (GB 43854-2024) (hereinafter referred to as the Technical Specification) drafted by the Ministry of Industry and Information Technology has been issued by the State Administration for Market Regulation (National Standards Committee) and will be officially implemented on November 1, 2024.
It is understood that the technical specifications stipulate the safety requirements and test methods for lithium batteries for electric bicycles applicable to the "Safety Technical Specifications for Electric Bicycles" (GB 17761) from the two levels of single batteries and battery packs. Among them, the single battery mainly considers six safety requirements: overcharge, overdischarge, external short circuit, thermal abuse, acupuncture, and marking; The battery pack mainly considers 22 safety requirements in 7 aspects, including electrical safety, mechanical safety, environmental safety, thermal diffusion, mutual recognition and collaborative charging, data collection, and marking.
It is worth noting that the technical specifications are only applicable to lithium-ion batteries for electric bicycles with a maximum output voltage of no more than 60V specified in the "Safety Technical Specifications for Electric Bicycles" (GB 17761), and are not applicable to lithium-ion batteries used in electric scooters, balance bikes, electric motorcycles, electric tricycles and other vehicles. According to the regulations, after the implementation of this standard, lithium-ion batteries for electric bicycles sold in China must meet its requirements.
At present, the social ownership of electric bicycles in mainland China has exceeded 350 million, and in 2023, enterprises above designated size in the country will produce a total of 42.28 million electric bicycles. More than 20% of the new models of electric bicycles released by major domestic electric bicycle brands are equipped with lithium-ion batteries.
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Authoritative interpretation
1. What is the background of the formulation of the Technical Specifications?
In recent years, the production and sales of electric bicycles in mainland China have grown rapidly, and the current domestic social ownership of electric bicycles has exceeded 350 million, and in 2023, enterprises above designated size will produce a total of 42.28 million electric bicycles. There are two main types of batteries used in electric bicycles: lead-acid batteries and lithium-ion batteries. Among the new models of electric bicycles released by major domestic electric bicycle brands, the proportion of lithium-ion batteries has exceeded 20%. With the expansion of the industrial scale, standards, as an important technical support for industrial development, have been continuously improved and improved, so as to standardize the design, production and sales of lithium-ion battery products for electric bicycles, and improve product quality.
2. What is the significance of the release of the Technical Specifications?
As a mandatory national standard for the safety of lithium-ion batteries for electric bicycles, the "Technical Specifications" will effectively improve the intrinsic safety level of lithium-ion batteries for electric bicycles, reduce the incidence of safety accidents such as fires during use, protect the personal health and life and property safety of consumers, and promote the healthy and orderly development of the electric bicycle industry.
3. Which vehicle batteries are the "Technical Specifications" applicable to?
The "Technical Specifications" are only applicable to lithium-ion batteries for electric bicycles with a maximum output voltage of no more than 60V as specified in GB 17761 "Safety Technical Specifications for Electric Bicycles". Lithium-ion batteries are not suitable for use in electric scooters, balance bikes, electric motorcycles, electric tricycles, etc.
4. What are the main types of lithium-ion batteries for electric bicycles? Do they all meet the requirements of the Technical Specifications?
Common lithium-ion batteries for electric bicycles mainly include lithium manganese oxide batteries, lithium ferrous phosphate batteries and ternary lithium batteries. Among them, ternary lithium batteries can be divided into nickel-cobalt-manganese batteries with high nickel systems, nickel-cobalt-aluminum batteries and nickel-free lithium manganese iron phosphate batteries.
The "Technical Specification" stipulates strict overcharge (1.5 times), acupuncture and other tests for single batteries, and it is difficult for high-nickel ternary lithium batteries to pass the above tests, and it will be difficult to be used in the field of electric bicycles in the future.
5. What are the test items specified in the Technical Specifications?
The "Technical Specification" stipulates 6 test items for single batteries, including marking, overcharging, over-discharge, external short circuit, thermal abuse, and acupuncture; 22 battery pack test items, including marking, electrostatic discharge, over-discharge, over-charge, temperature protection, external short circuit, mutual recognition of collaborative charging, data acquisition, insulation resistance, extrusion, acceleration shock, vibration, free drop, handle strength, flame retardancy, low air pressure, over-current discharge, temperature cycling, water immersion, salt spray, damp heat cycling, thermal diffusion.
Among them, the following test items need to be focused on:
1. The overcharge (1.5 times) test and acupuncture test of the single battery can effectively screen the safety of the battery.
2. The battery pack should have a unique code, and the code identification needs to be made of high-temperature resistant (950°C) material, which can be traced even in the event of a fire.
3. The overcharge, external short circuit, and overcurrent discharge tests of the battery pack should be carried out under normal working conditions and under the condition of single fault of the protection components, so the battery pack may need to adopt a double protection design to meet the requirements.
4. The battery pack needs to have a mutual recognition and collaborative charging function to reduce the risk of charging the battery pack caused by the mismatch of the charging device.
5. The battery pack should collect the battery voltage, battery pack voltage/temperature/current in real time during the charging and discharging process, which requires the battery pack to be equipped with a management system (intelligent "brain") for real-time monitoring.
6. Manufacturers should clearly mark the "safe service life" on the battery pack to remind users to phase out old batteries in time, because as the service life of lithium-ion batteries increases, their safety risks will gradually increase.
7. Flame retardant materials should be used for the shell, printed circuit board, and wires of the battery pack to reduce the spread rate of flames after a fire.
8. The thermal diffusion test of the battery pack requires that when a single cell in the battery pack catches fire, it shall not spread rapidly to the entire battery pack.
6. What are the aspects of the "Technical Specifications" to improve the intrinsic safety of batteries?
The "Technical Specification" not only stipulates the safety requirements of lithium-ion batteries for electric bicycles, but also sets the product safety access threshold for battery packs from seven aspects, including electrical safety (including overcharge, overdischarge, external short circuit, temperature protection, etc.), mechanical safety (including extrusion, acceleration shock, vibration, etc.), environmental safety (including low air pressure, temperature cycling, water immersion, etc.), thermal diffusion, mutual recognition and collaborative charging, data collection, and marking, so as to improve the intrinsic safety level of lithium-ion batteries.
7. Do all e-bike batteries have to comply with the Technical Specifications?
According to Article 25 of the Standardization Law of the People's Republic of China, "products and services that do not meet the mandatory standards shall not be produced, sold, imported or provided." ”。 Therefore, after the implementation of this standard, lithium-ion batteries for electric bicycles sold in China must meet its requirements.
8. How can consumers buy lithium batteries that comply with the "Technical Specifications"?
When purchasing an electric bicycle, consumers can confirm whether the battery meets the "Technical Specifications" by checking the nameplate, specifications, instructions for use and other information of the battery, or asking the seller to request the corresponding "Technical Specifications" test report or certification certificate of the product.
9. Why is it required to mark the safe service life of the battery?
With the increase of service life, the capacity of lithium-ion batteries gradually decreases, and the existing safety risks will gradually amplify. The "Technical Specifications" require manufacturers to mark the "safe service life" on the battery pack, remind users to eliminate old batteries when they expire, reduce the potential safety risks caused by old batteries, and protect the safety of users' lives and property.
Producer: Liaoning Provincial Fire and Rescue Corps All Media Center
Source: China Fire Protection