An independent test of BYD's new megawatt flash-charging system showed the battery surface heating up to 76.4°C during ultra-fast charging. The results immediately sparked a discussion on Chinese social media about battery longevity and the risks of thermal stress.
Chinese auto blogger James Yu (Caishendao) live-streamed the charging of a BYD FCB Tai 3 model — from 8% to 97% charge. Temperature was measured in two ways: through the car's diagnostic data and external sensors attached to the battery pack surface. The system is based on second-generation Blade batteries with liquid cooling. However, temperature management is precisely the main limitation for charging "almost like refueling with gasoline."
The maximum temperature on the external sensor reached 76.42°C, while the car's diagnostic system showed about 71°C. This is above the recommended threshold of 65°C specified in the appendix of the Chinese standard GB/T 44500-2024 for LFP batteries.
This refers to the surface temperature of the battery pack, not the internal temperature of the cells. BYD also did not report any malfunctions or changes in system characteristics. The blogger himself later clarified that definitive conclusions about battery degradation cannot yet be made — additional tests are still to come.
Ultra-fast charging is becoming a key weapon for Chinese brands in the battle for customers. BYD is actively deploying a network of megawatt stations: the company already claims over 5,700 locations in China. But the higher the charging power, the more challenging the task of thermal control.