Modern hazard
Lithium-ion battery safety
E-bikes, e-scooters, vapes, laptops, cordless tools and power banks — almost every rechargeable in the home now runs on lithium-ion. Handled correctly they are safe; handled wrong they are one of the fastest-growing causes of serious house fires in the UK.
If a battery is smoking or on fire
- • Get everyone out immediately — including pets — and close the door behind you.
- • Call 999. Tell them it is a lithium-ion battery fire (the fire brigade uses different tactics).
- • Do not attempt to use water or a domestic extinguisher on a large pack — thermal runaway will reignite.
- • Do not go back in for the device. Nothing on that battery is worth your life.
Why lithium-ion is different
Thermal runaway is fast and violent
Once a lithium-ion cell goes into thermal runaway it can hit 600 °C in seconds, vent toxic hydrogen-fluoride gas and set fire to anything nearby. Standard smoke alarms detect the smoke — but by then the escape route may already be blocked. Prevention is everything.
Charge on a hard, non-combustible surface
Never charge on a bed, sofa, carpet, or under a pillow. Charge on a tiled floor, laminate, worktop or in a metal cabinet. Don't cover the battery or charger while charging — heat has to escape.
Use only the manufacturer's charger
Counterfeit and "universal" chargers do not match the battery's charge profile — they overcharge, over-current or fail to cut off at 100%. Fake chargers are the single biggest cause of e-bike and e-scooter fires. Buy from the original manufacturer or a UK-authorised retailer.
Five rules to live by
Never charge overnight or when you're out
The vast majority of lithium-ion fires start during charging. If you cannot see or hear the device, you cannot respond to a fault. Charge when you are awake and at home — unplug when full.
Keep charging routes clear of escape
Do not charge an e-bike, e-scooter or larger battery in a hallway, stairwell or the only exit from a bedroom. If it ignites, it must not block the way out. A garage or outbuilding is far safer than the hallway.
Stop using a swollen, damaged or hot battery
Bulging casing, hissing, popping, an unusual chemical or fishy smell, or a battery that is hot when it should not be — all signs of a failing cell. Do not attempt to use, charge or bring the battery inside. Move it (carefully, wearing gloves) to a metal container outdoors, well away from anything combustible, and contact the manufacturer.
Register the product and honour recalls
Register e-bikes, e-scooters, power banks and cordless tools with the manufacturer. Recalls are common — the Office for Product Safety and Standards publishes them at gov.uk. Recalled batteries have a known failure mode; keep using them and you are gambling.
Never buy converted, DIY or refurbished battery packs
Second-hand or backyard-repaired e-bike packs, especially those built from mixed 18650 cells with a cheap BMS, are behind many high-profile fires in the UK. Buy new, from the original supplier, and never mix packs.
Home battery storage (LFP) — a note
Modern domestic battery storage systems (Tesla Powerwall, GivEnergy, SolarEdge Home Battery, etc.) use LFP (lithium iron phosphate) cells — chemically far more stable than the NMC cells in e-bikes and phones, and installed under BS 7671:2018+A4:2026 Chapter 57 with dedicated protection. They are not the same fire risk as an unbranded e-bike pack. Paul installs and inspects these systems to the current regulations.