Stop
A swollen or extremely hot lithium battery can catch fire or vent toxic gas. Stop use immediately, keep it away from anything flammable, and take it to a battery recycling center rather than a repair shop.
Symptoms
- Battery casing looks bulged or misshapen
- Battery feels excessively hot even when not charging
- Battery won't sit flush in the tool or charger anymore
- Unusual smell from the battery
Likely causes
- CommonInternal cell degradation or damageAge, deep discharges, or physical damage can cause lithium cells to swell.
- PossibleOvercharging from a faulty chargerA malfunctioning charger can overcharge cells and cause swelling.
- PossibleExposure to extreme heatLeaving batteries in a hot car or direct sun can accelerate degradation.
What to do
- Stop using the battery immediately and do not attempt to charge it further.
- Move the battery outdoors or to a non-combustible surface away from flammable materials.
- Do not puncture, crush, or attempt to open the battery casing.
- Contact your local hazardous waste or battery recycling program for safe disposal.
- Check the charger with a different, known-good battery to see if the charger itself is faulty.
- Replace the battery with a new one rather than continuing to use a swollen pack.
- If you notice smoke, extreme heat, or a leak, move it outside immediately and call your local fire department for guidance.
Tools and parts
Replacement cordless tool batterySearch: “cordless outdoor tool battery replacement”
When to call a pro
Battery recycling centers, not repair shops, are the correct place to safely dispose of a swollen lithium battery.
Safety
Stop
A swollen or extremely hot lithium battery can catch fire or vent toxic gas. Stop use immediately, keep it away from anything flammable, and take it to a battery recycling center rather than a repair shop.