Fire regulations for charging lithium batteries

While lithium-ion batteries are widely used, regulations around their fire safety are still developing. At present, there are no UK standards specifically focused on the fire safety performance of lithium batteries. However, broader safety standards and legal requirements do apply.

China has just enacted the world's strictest fire prevention standards for lithium-ion EV batteries. Lithium-ion batteries, including those used in electric vehicles, pose fire dangers primarily due to their sensitivity to overheating, physical damage, electrical faults, and improper charging.

The most significant change in the new standard is the thermal diffusion test requirement. While the previous standard only required a warning signal five minutes before fire or explosion, the updated regulation mandates that batteries must not catch fire or explode, even during thermal runaway events.

Set to take effect on July 1, 2026, the “Safety Requirements for Power Batteries of Electric Vehicles” will essentially prohibit fires and explosions even after thermal propagation, or the spread of an uncontrolled temperature increase from one battery cell to another.

While the previous standard only required a warning signal five minutes before fire or explosion, the updated regulation mandates that batteries must not catch fire or explode, even during thermal runaway events. Additionally, any smoke generated must not harm vehicle occupants. The standard also introduces new tests, including:

Other relevant standards include UL-1642 and UL-9540, which also address battery safety and performance. Moreover, the proposed Safety of Electric-Powered Micromobility Vehicles and Lithium Batteries Bill aims to introduce stronger regulation in the UK.