A Li-ion in Winter

Tips for using a digital camera in extremely cold weather.

Here are a few tips about how to get maximum life from your batteries in low temperatures.

Interestingly, I can’t find anything on the Web that supports the tips I’m about to give you, and I’ve never read about it in print sources.  I’m sure it’s not a breakthrough scientific discovery, but I can’t back it up with authoritative sources, at least none that I can find.  So, you might have to consider this something of a “myth,” but you can easily confirm it on your own.

Here’s the thing.  Electric batteries are a lot like old, cranky birdwatchers.  They get slower and crankier when it’s cold.

It doesn’t matter what kind of batteries you have, whether primary or rechargeable, carbon or alkaline, nickel-metal hydride or lithium-ion, lead-acid automotive batteries, or, I dare say, any battery that’s ever been invented or likely to be invented any time soon.  They all operate much better at temperatures closer to normal human body temperature than to the temperature of ice.

You can observe this very easily.  If you keep your camera (or other battery-powered device) outside in very cold temperatures, you’ll see that the batteries are depleted very quickly.  Place the camera inside your jacket for a few minutes, and the batteries indicate a much higher charge.

Any battery produces electric power by chemical reactions, and any chemical reaction occurs more efficiently at higher temperatures, within reasonable limits.  Just don’t drop your batteries into a fire and expect them to work better.

So what can you do about it?  Two things, one simple and one with ramifications.

First, carry your extra batteries in an inner pocket.  (You do dress in layers when you go outdoors in winter weather, don’t you?  Good!)  The nearer to your skin, the better.  I typically carry my extra batteries in my shirt pocket, with a couple of layers outside of that.

Second, keep your camera as warm as possible while you’re not actually using it.  This, as I alluded above, has ramifications.  The problem is that if you keep your camera at your body temperature, condensation will form on the lenses when you start using it.

So, while your extra batteries benefit from being kept at body temperature, the camera itself has problems with that.  Here are a couple of techniques that I use to reach a balance between these two requirements.

1.    Keep your camera at an intermediate temperature and, if possible, keep the battery warmer than the lens.  I keep my camera in an inside pocket of my outermost jacket, and I keep it lens-side-up.  Typically, my outermost jacket is unzipped, so the top of that inner pocket is only marginally warmer than ambient temperature.  The battery-end of my camera is buried deep inside a sort-of warm pocket, while the lens is just outside of the frigid White Mountain wilderness.
2.    Change out the batteries throughout the day, cycling them between the camera and your inner pocket.  When the battery in my camera indicates that it’s “dead,” I install the extra battery and put the “dead” one in my shirt pocket.  Then, when that second battery is “dead,” I switch back to the original battery, which is now warmed up and, magically, no longer “dead.”

One final note:  When you get back home, do not place a cold battery on its charger.  Let the batteries warm up to room temperature for a few hours before charging them.  The sudden change of temperature from freezing to charging, and the sudden flow of electrical current through a cold battery, will almost certainly cause permanent damage.

More details, and more ways to use this same underlying knowledge, are at http://www.HikingWithChuck.com/Gear/ALiIonInWinter.htm.