Cold weather poses a problem for lithium batteries—they can lose their charge more quickly and also become unable to charge as temperatures drop. This is because the chemical reaction in a lithium ion battery will slow down when the temperature drops below about 40 degrees. If you have battery powered snow-removal tools or if you just have outdoor home projects you need to tackle when it’s cold outside, this can be frustrating. It’s more than frustrating when you take into account that charging batteries outside of the safe charging temperature range can damage them permanently. Here are some steps to take to keep your batteries working, even when the mercury drops.
First, you should store your tool batteries in a climate-controlled environment during the cold winter months. If you have an unheated garage, you should bring batteries and chargers indoors to avoid damage, but also to avoid the step of warming batteries up before charging them. This will help you prevent the most common type of winter battery damage, which is caused by attempting to charge batteries in temperatures below 40 degrees. Also, getting a full charge is the first step to extending battery life later on.
When you’re not using tools outdoors, you can use the pocket method to keep them warm. Slipping idle batteries or spares into a coat pocket, or better yet, an inside pocket closer to your body, will help them stay warm and avoid losing charge when they’re not in use. Using your own body heat has the added benefit of being free, but it’s limited by the number of pockets you have for carrying capacity. If you’re using a larger tool that requires multiple batteries, you might need something a little more advanced.
When you’re using your tools, keeping them running while they’re in the cold will warm up the batteries a little bit—but the downside is that running the tools all the time also reduces battery life. For a short job, or for snow-removal tools like snow blowers, this might be okay, but for longer-term cold-weather use, you’ll need to take more steps to keep the battery juice flowing.
When tools are in use, consider using a battery cover to help keep tool batteries warm. These are usually made from silicone, but you can also fashion one out of neoprene foam or another flexible insulation material. Adding covers to your batteries does make battery changing a clumsy affair, but if the insulation buys you some more battery life, you won’t need to swap them out as often.
To charge batteries outdoors, or to keep batteries in the temperature range where they will hold a charge, using an insulated lunch bag or a cooler to keep them warm can work wonders. A soft-sided lunch bag can accommodate charged batteries, but you can also run the cord for a charger through the opening, zip it closed around the cord, and use a battery charger inside the bag to avoid damaging the battery during charging. With a hard-sided cooler, you’ll need to cut slots in the lip around the top of the cooler between the sides and the lid to accommodate cords for chargers, but these can be excellent for containing heat during charging.
Using hand warmers as a back-up heat source or when the temperature is extremely cold can also help, and can be used in conjunction with both the pocket and the cooler method of battery insulation. There are both disposable and reusable hand warmers, so you can choose whichever one works best for your conditions. While you don’t want your batteries to get too hot (over 100 degrees), some instances call for external heat sources. You can toss a hand warmer into your battery insulation cooler, or you can use one in your pocket if you notice that the batteries are getting chilly.
