Cottage Q&A: How to store lithium batteries

Lithium batteries stacked on top of each other By ArnyGFX/Shutterstock

What’s the best way to store Li batteries? I have a pack for an electric chainsaw and several individual 18650 2500mAh cells. I put them all in a steel military ammo box and keep them in my unheated garage.—George Waters, via email

Ideally, you want to store lithium-ion batteries at about 40 per cent charged and above 0°C. “Lithium is a great product, but it is more sensitive than lead acid,” says Phil Beauchamp, the owner of Rosspar Limited and Batteries Expert in Pickering, Ont. Freezing probably won’t destroy the batteries, but it will likely affect their ability to hold a charge. The steel box, meanwhile, is unnecessary, says Beauchamp. “People get scared about lithium batteries catching on fire. But when that has happened, it’s been during charge, or during discharge when someone was operating a tool,” he says. “And it was usually because there was a problem with the battery or because the tool was used incorrectly.”

(In 2006, Sony issued a worldwide recall for their Li-ion computer batteries because of “overheating incidents”—people’s laptops were bursting into flames; in 2015, Li-ion-powered hoverboards became notorious for exploding. In both cases, experts believed manufacturing defects, and cut corners, were to blame.)

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Is it possible that your batteries could explode while sitting inert? Well, heck, anything’s possible. But “that’s incredibly unlikely,” says Beauchamp.

Keeping the batteries in a metal box while you charge them, however, isn’t a bad notion, says Isidor Buchmann of Cadex Electronics in Richmond, B.C. “I wouldn’t discourage anyone from doing it,” he says. At the very least, “it provides peace of mind.”

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This article was originally published in the June/July 2020 issue of Cottage Life.

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