The hazard
Thermal runaway can spread from one cell to the next
A lithium-ion cell can overheat after damage, defect, internal short circuit, inappropriate charging or exposure to heat. Self-heating may accelerate, venting flammable gases and transferring heat to neighbouring cells.
The risk in a phone or laptop is not the same as an e-bike charging room, battery-energy-storage system or waste-battery facility. The FRA should record battery type, quantity, energy, condition, charging, separation and occupancy.
Control before suppression
Charging, storage and separation provide the first controls
Use compatible manufacturer-approved charging equipment, follow instructions, inspect for damage or swelling and keep escape routes clear. Do not create charging areas in protected escape routes or where a fire could trap sleeping occupants.
Commercial and higher-energy arrangements may require dedicated locations, detection, ventilation, fire-resisting separation, quarantine for damaged batteries and emergency isolation.
- Battery inventory and responsible owner
- Approved chargers and electrical provision
- No charging on protected escape routes
- Damage, recall and quarantine procedure
- Combustible separation and housekeeping
- Detection, isolation and emergency instructions
Portable equipment
Do not treat a specialist extinguisher as a universal answer
Environment Agency guidance recognises several possible suppression and cooling methods and says the most appropriate depends on the battery type, quantity, location and scale. Large battery rooms and fixed systems require specialist design; portable extinguishers should not be used as a substitute.
Check the product’s tested scope and instructions. Marketing terms such as “lithium” or a coloured band do not prove suitability for every lithium-ion battery. Lithium metal and lithium-ion hazards are also not interchangeable.
Emergency response
Evacuate early and warn the fire and rescue service about batteries
If a device becomes unusually hot, swollen, hisses, vents or smokes, follow the premises emergency plan, raise the alarm and move people away without taking personal risk. Call 999 and provide information about the battery type, quantity and location.
A battery may re-ignite after apparent extinguishment. Do not move, reopen or return damaged equipment to use without a competent post-incident plan.