Which batteries are suitable for use in (higher-powered LED) flashlights and (higher-drain) tools in cold weather?
The quick answer: lithium.
In general, alkaline batteries perform very poorly in cold weather. As alkaline batteries are engineered with a water-based electrolyte, cold near-freezing point temperatures can lead to reduced ion mobility which slows down the chemical reactions that provide electrical battery power. This leads to a drop in performance, runtime, or both.
In some cases, cold temperatures can cause alkaline batteries to burst and leak.
Rechargeable batteries tend to perform poorly in cold temperatures as well. I typically use Sanyo Eneloop NiMH batteries in my AA and AAA-sized flashlights, but these batteries aren’t any better than alkalines when temperatures drop near freezing.
According to Sanyo’s datasheet (PDF), basic AA Eneloops are only rated down to 0°C/32°F. Any colder than that and you can probably expect to see greatly reduced performance in medium and high-drain flashlights and devices.
Lithium batteries, on the other hand, perform quite well when it’s cold out.
Panasonic’s CR123A lithium batteries (PDF) have an operating temperature range of -40° to + 70°C (-40° to 158°F), while Energizer’s Ultimate Lithium L91 AA batteries (PDF) have a similar operating temperature range of -40° to 60°C (-40° to 140°F).
Based on recommendations stated in Panasonic’s datasheet and this capacity vs. temperature chart in Energizer’s L91 datasheet, both battery types are practically effective at temperatures down to about -20°C, or -4°F. Beyond that you are likely to see greatly diminished performance.
In addition to cold weather performance, CR123/CR123A and Energizer Ultimate Lithium batteries have longer shelf lives and higher charge capacities than alkaline batteries. You wouldn’t want to buy premium lithium batteries to power your TV remote, but they typically do work better and last longer in high-drain devices (such as bright LED flashlights).
I am not trying to suggest that alkaline batteries cannot be used in cold weather applications, but that lithium batteries will perform better, especially in higher drain devices. According to an Energizer white paper (PDF), and another by Duracell (PDF), their alkaline batteries will work at freezing temperatures, albeit at greatly reduced capacity.
In regard to alkaline batteries – but applicable to all other battery chemistries including lithium: as current drain increases, temperature impact becomes more dramatic. (Section 5.4 of Duracell’s bulletin.)
You can find both types of batteries for under $2.50 each in retail stores, or under $2/each online.
Buy Now: Energizer L91 (AA), Energizer L92 (AAA), CR123 (via Amazon)
With CR123/CR123A batteries, stick to reputable brands such as Streamlight, Energizer, Surefire, and Panasonic.
Energizer has a newer more economical Advanced Lithium battery, but their Ultimate Lithium batteries are the ones you want for cold weather applications.
There are plenty of CR123 lithium battery options, but we’re still searching for AA and AAA-sized alternatives to Energizer Ultimate Lithium batteries. If you know of any, please let us know!