The process of thermal runaway starts when a battery cell overheats, perhaps due to an internal fault, physical or electrical abuse, or extreme temperatures. This elevated cell temperature results in exothermic reactions, which produce more heat than can be dissipated to surroundings. Eventually the internal structure of the cell begins to become unstable and collapse, resulting in the venting of flammable and toxic gases, fire and explosion. The heat spreads to nearby cells, causing them also to enter an uncontrollable and irreversible state of thermal runaway.
In the videos below you can see what can cause thermal runaway to occur, especially in relation to e-bikes and e-scooters along with advice on what to do if you find yourself in a situation where thermal runaway happens. Additionally we have footage of thermal runaway occuring during a session at a test lab that shows just how dangerous these fires are.
If you find yourself in a situation where thermal runaway is happening:
- Warn others
- Get out
- Call the fire service.
Find out more about thermal runaway in our new report Battery Breakdown.
Return to the Battery Breakdown portal.