Monday, January 29, 2007
POWER GUIDE: Battery Options & Tips
New batteries and chargers let you keep shooting and shooting and shooting...
Lithiums. Disposable lithiums greatly outperform most other batteries. Although lithium disposables cost a little over twice the price of an alkaline battery, they last about three to five times longer than the alkalines do in digital cameras and electronic flash units. Like the rechargeables, lithiums recycle your flash unit quickly and maintain most of that speed until they're used up. They share Li-Ion batteries' resistance to cold and can deliver the bulk of their capacity even in freezing weather.
Lithium disposables also have about double the shelf life of alkalines—if your camera can use them, disposable lithiums make a great backup for rechargeables.
Whichever battery you choose, how you use your camera and the type of pictures you take can affect battery life. One of the best things about digital photography, the LCD monitor, also is among the hungriest for battery power. Turn your camera off when you're not using it, and keep image review times as short as possible.
For those of us making time exposures at night, keeping the shutter open-and the sensor live—for long periods eats power more rapidly than quick handheld shots. Cooler temperatures at night don't help power consumption either—if you do a lot of this kind of shooting, make sure to have spare batteries on hand.
"Is It Dead Yet?"
Except for alkaline batteries, which put out less and less power as they're discharged, other battery types put out a fairly constant voltage until they're nearly exhausted. That's generally good news, as it means your gear will keep working consistently while the batteries have juice, but there's a downside. The first is that apart from the alkalines, there's little warning of impending battery exhaustion—your batteries can produce normal power levels one minute and be dead shortly thereafter.
Because most battery-check indicators rely on output voltage to estimate batteries' remaining strength, the indicators in your camera aren't much better at predicting battery exhaustion than you are. At best, they can merely report that you're "nearly" exhausted, just before the battery quits.
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