Shanghai (ZXZC)- China issued on May 12 three mandatory national standards about the safety of EVs and EV batteries (hereinafter referred to as “the mandatory standards” collectively), which will come into force on January 1, 2021.

The mandatory standards are formulated by China's Ministry of Industry and Information Technology (MIIT), and approved by the State Administration for Market Regulation (SAMR) and the Standardization Administration Committee (SAC). Based on the existing voluntary standards and geared to the Global Technical Regulation on Electric Vehicle Safety (UN GTR 20), the new compulsory one is designed to further raise and optimize the technical requirements on the safety of EVs and power batteries.

(BYD e2)

The newly-launched safety standards focus on three aspects, namely, the EV-used rechargeable battery, the EV and the electric bus.

The standard for the safety of EV battery not only points out the improvement on the safety of battery cell and modules, but also highlights stricter requirements on that of battery thermal system, machinery, electrical system and functions. The tests should take account of the system thermal diffusion, external fire, mechanical shock, simulated collision, thermal and humidity cycling, external short circuit, overcharge and over-temperature.

Besides, thermal runway of one cell should cause no fire or explosion for at least five minutes in a bid to afford the drivers and passengers with enough time to escape.

The EV safety standard mainly stipulates the requests on EV’s electrical and functional safety. A battery system is required to warn a driver of thermal accidents immediately, which is a new item over the current voluntary standard. Moreover, it underlines more stringent requirements over EV performances of watertightness, insulation resistance and monitoring, with a view to lowering the security risks for both vehicles in normal operation and waterlogged vehicles. To ensure the safety of EVs using high-voltage batteries, the new standard also improves the methods for testing such performances as insulation resistance and capacity coupling in order to elevate the testing and detection accuracy. 

The last one is set for the security of electric bus. Given the big busload, large battery capacity and high driving power, the new standard put forth more rigorous safety demands on battery holder collision, charging system and vehicle watertightness test. Moreover, it also adds the request on flame-retardant performance of high-voltage parts, and the appraisal requirements over thermal runaway of the battery system’s minimum management unit.