Why this happens
Swelling, hissing, smoke and sweet or chemical smells are signs that cells inside the battery are breaking down and releasing gas, which can lead to thermal runaway. These failures can escalate quickly, and smoke from lithium batteries is toxic, so the right response is to protect people and get professional help, not to investigate.
What you need
Tools
- Phone to call 112
- Heat-resistant gloves (only for a cool, non-smoking battery)
Materials
- Open outdoor area with a non-combustible surface such as concrete or sand, away from buildings and vehicles
Before you start
- People come first. Do not pick up, carry or try to cool a smoking, hissing or burning battery.
- Smoke from lithium batteries is toxic; stay out of it and ventilate only after the fire service says it is safe.
- Do not charge, use or store a battery that has swollen, smoked or smelt unusual, even if it seems fine later.
- If someone is injured or affected by smoke, call 112 and follow the operator's instructions.
Step by step
- 1
Stop charging or riding at once
If you notice the signs while charging, switch off the wall socket if you can reach it safely, then unplug. If you are riding, pull over safely, switch the vehicle off and step away from it. Do not continue the journey or resume charging to see if the problem goes away.
- 2
Judge the danger quickly
If there is smoke, hissing, popping, sparks, flames or the battery feels very hot from a distance, treat it as an emergency: do not touch or move it. If it is only slightly swollen or smells unusual but is not hot or smoking, you have a little more time, but still treat it as dangerous.
- 3
In an emergency, get everyone out
Get all people and pets out of the room or building, closing doors behind you to slow smoke if it is safe to do so. Call 112 and tell them a lithium-ion battery is involved and where it is. Do not go back inside for belongings, and keep away from the smoke, which contains toxic gases.
- 4
If cool and not smoking, isolate it
Only if the battery is cool, not smoking or hissing, and is a removable pack you can lift safely, wear gloves and move it outdoors onto concrete or sand, well away from buildings, vehicles and anything that can burn. If it is fixed in the vehicle, move people away and keep the vehicle outdoors in the open if you can do so safely.
Tip: Never put a damaged battery in a car boot, lift or closed room.
- 5
Keep watch from a distance
Keep children, pets and onlookers well away. Watch from a safe distance for smoke, flames or worsening swelling for several hours, since a damaged battery can fail some time after the first signs. If it starts smoking or burning, call 112 and keep everyone back.
- 6
Do not open, puncture or test it
Do not press on a swollen battery, open its case, puncture it, charge it or connect a meter to check it. Do not throw it in household waste or water bodies. Each of these can trigger a fire or release harmful chemicals.
- 7
Contact the manufacturer or service centre
Once the situation is stable, contact the vehicle manufacturer, dealer or authorised service centre. Describe what happened, when and any photos you took from a safe distance. They can arrange safe collection, inspection and warranty processing. Keep your purchase and service records ready.
How to tell it worked
Everyone is safe and away from the battery, emergency services were called if there was smoke or fire, a cool damaged battery is isolated outdoors, and the manufacturer or service centre has been informed.
Stop and call a technician if
- Any sign of smoke, flame, hissing or heat; evacuate and call 112.
- The battery is swollen, cracked or leaking; do not use it again and arrange collection through an authorised service centre.
- The vehicle is under warranty; let the manufacturer inspect it before anyone opens or repairs anything.
Questions
Can a slightly swollen battery be used until I get a replacement?
No. Swelling means gas is building up inside damaged cells, and it can fail without further warning. Stop using it and contact the service centre.
Should I put a damaged battery in a bucket of water?
Do not handle it beyond the steps above. Keep it outdoors on a non-combustible surface, keep people away and let the fire service or manufacturer deal with it.