Storing your power tool batteries in winter: the right habits

Your battery-powered tools are going into hibernation? Lithium-ion batteries don't like extreme cold, don't like being left flat, and don't like being charged to 100% for months on end. A few simple rules prevent finding a battery in spring that no longer holds any charge. Here's how to store them properly.

The ideal charge: neither full nor empty

Contrary to popular belief, you don't store a lithium battery either completely charged or completely empty for a long period. The ideal zone is around 40 to 60% charge. A battery left flat all winter can discharge deeply and become irretrievable.

Cold, an enemy

Lithium hates extreme cold. Avoid storing batteries in an uninsulated garage or shelter that drops below freezing: store them indoors instead, in a temperate and dry room. Cold doesn't destroy the battery instantly, but prolonged freezing storage accelerates its aging.

The right habits

• Separate the battery from the tool (prevents constant micro-discharge).
• Charge to ~50% before storing.
• Dry and temperate location, sheltered from humidity and temperature fluctuations.
• Check once during winter and recharge a bit if the level has dropped significantly.
• Never leave a swollen or damaged battery stored — send it for recycling.

For understanding platforms and compatibility, see power tool battery platforms.

In spring

Recharge fully before resuming use, and if a battery has lost a lot, it's a sign it's nearing the end of its life. Careful storage, winter after winter, significantly extends its lifespan.

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