Monday, January 29, 2007
POWER GUIDE: Battery Options & Tips
New batteries and chargers let you keep shooting and shooting and shooting...
NiMH. The first real alternative to alkalines and NiCds, NiMH batteries can store as much as 40 percent more energy than NiCds, and they're far more resistant to cold than alkalines, providing superior capacity in those conditions. NiMHs don't suffer from memory problems like NiCds, so you can freely recharge them without needing to drain them all the way first. Since NiMHs can be recharged about 500 times, they cost next to nothing to run.
In flash units, NiMHs recycle your flash in half the time than fresh alkaline batteries. Unlike alkalines, NiMHs' recycling times won't get longer and longer as the battery's charge is used up.
So what's the catch? Like all rechargeables, NiMH batteries may lose 1 to 2 percent of their charge per day just sitting in your camera bag. If you charge your battery and let it lie around for a few weeks before you use it, you'll only get a fraction of the shots you were expecting. Let your batteries sit longer between uses, and you could come back to a discharged battery.
Li-Ion. These batteries have terrific capacity, they're much smaller and lighter than other batteries that hold the same energy, and they're even more resistant to cold than NiMHs. Like NiMHs, they're free of memory problems, and they can be recharged up to 1,000 times. Li-ion batteries also self-discharge and will need to be recharged after sitting for several weeks. These batteries require a dedicated charger; if you use a third-party unit, make sure it's compatible with the battery you're charging.
Alkalines. While alkaline technology isn't at all new, it works well enough in flash units and other devices that get only occasional use. Alkalines aren't the best choice if you're going to be shooting lots and lots of images, but they do have some advantages: Unlike rechargeables, you always can buy more of them at the supermarket—or in the Grand Canyon—and they're inexpensive.
Digital cameras drain alkalines quickly, making the batteries costly to use if you shoot a lot. In flash units, recycle times increase dramatically as the batteries are used up; before the alkalines are spent, you'll wait twice as long or more for the "flash-ready" light to come on.
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