Four tips for making camera batteries last
Like a desert mirage, revolutionary new battery technologies always seem to be just beyond the horizon. New materials, nanotubes, and fuel cells all offer the promise of dramatically longer runtime and shorter (or nonexistent) recharges. But until that elusive day comes, we're going to have to contend with our existing battery technology. Recently, I offered some tips for dealing with your memory card, so this week I thought we should turn our attention to batteries. Here are a few tips for getting the most out of your camera batteries.
Check your batteries before hitting the road
Batteries lose their charge continuously, not just when in use. That means you shouldn't charge up a battery, put it in your camera, and then let it set in the closet for three months. When you eventually do reach for your camera, you might find that the battery is already dead, or nearly so—and you haven't taken a single picture.
If you've already had this happen to you, don't worry—it's the way that batteries work. All batteries slowly lose their energy when they're sitting idle, but how slowly depends upon the kind of battery. Alkaline batteries are extremely stable—they'll only lose 1 or 2 percent of their total capacity over an entire year. And that's a good thing, because they need to work well after sitting on a store shelf for a long time.
Rechargeable batteries, however, are far more volatile. Typical NiMH batteries, for example, can lose about 1 percent per day—so a fully charged battery will be depleted after 3 or 4 months just by sitting idle in your camera. Keep that in mind when you grab your camera bag before your next trip.
Store batteries in the fridge
You might have heard that batteries stay "fresh" longer when stored in the refrigerator or freezer. That's not a myth: It's absolutely true, but there are some caveats.
Freezing your battery works because the chemical reactions that generate electricity are temperature dependent. When you put a battery in cold storage, you impede the process, so the battery loses its charge more slowly. But remember how I said that alkaline batteries lose their capacity very slowly? That means there's essentially no advantage to putting store-bought batteries in the freezer. The best you can hope to recover is some fraction of a percent of its overall charge over the course of a year. The freezer space is better dedicated to frozen custard. (I recommend a batch from Shake Shack in New York.)
There's a lot of value in freezing rechargeable batteries, though. According to Greenbatteries.com, rechargeable batteries stored in a freezer will retain over 90 percent of their charge for a full month.
Warm your batteries for better performance
Shooting outdoors in the winter? Your battery might give up fairly quickly, leaving you with a camera-shaped paperweight. That happens for the same reason that freezing batteries make them keep their charge longer—the cold impedes the electricity-generating chemical reaction. Batteries discharge better when they're warm. So if your battery does quickly die due to the cold, remove it from the camera and warm it up using your hands inside your jacket. If you can raise the battery's temperature, it'll spring back to life and allow you to take a few more pictures.
Use your camera to shoot pictures—and that's all
Here's some advice that seems obvious, but still manages to regularly elude folks. Everything you do with your camera uses battery power, so if you have only one battery and have no ability to charge up, don't use all the extra features on your camera. Specifically, don't use your camera to review photos, delete images from the memory card, or record audio annotations about each photo. Stick to the basics: Taking pictures.
Similarly, it's worth pointing out that long exposures—like you'd take to capture light trails in night photos and blurry waterfalls—use significantly more power than faster, ordinary snapshots. If you are trying to take special effects shots like those, know that you won't be able to capture as many photos as usual, and pack a spare battery.