Cordless Batteries in Hot Weather: Using, Charging and Storing Them Safely

Lithium-ion tool packs don't like heat. High temperatures make them age faster, and very hot packs can become dangerous.

1. What heat does

• Cells lose capacity faster when they're kept hot.
• Hard work in hot weather heats packs from the inside as well as the outside.
• Very hot or damaged cells can go into thermal runaway, which can cause fire.

2. Why the charger won't charge a hot pack

Most chargers check the pack temperature and wait until it cools. A flashing light after heavy use often just means "too hot, waiting". Let it cool in the shade. Don't put it in a fridge or freezer.

3. On the job

• Keep spare packs in the shade, not on the dash or in a closed ute tray.
• Rotate packs so each one gets a rest.
• If a pack is too hot to hold comfortably, stop and let it cool.

4. Storage

• Store packs somewhere cool and dry, out of direct sun. A hot shed or car in summer can get very hot.
• For long storage, many makers suggest a part charge rather than full. Check the manual.

5. Warning signs

Stop using a pack and keep it away from anything flammable if it's swollen, cracked, leaking, smoking, hissing or smells odd. If it catches fire, get away and call 000.

6. Quick summary

• Keep packs shaded and cool.
• Let hot packs cool before charging.
• Store cool, dry and part-charged.
• Retire damaged packs safely.

Follow your tool and battery maker's instructions. Don't open a pack or a mains-powered charger, and recycle any pack that is swollen, burnt, leaking or damaged.

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