During the first few generations of digital cameras, you couldn’t help but pay a lot of attention to batteries. Early-model cameras were notoriously power-hungry, burning through a full charge in minutes, not hours. It was left to the battery manufacturers to develop longer-lasting, faster-charging power sources that could keep shooting for a reasonable period of time.

Cameras have come a long way in reducing their power consumption, but development of battery technology has continued to push ahead. The common battery chemistries of a few years ago—nickel cadmium (NiCd) rechargeable and conventional alkaline cells—are still around, but they’re no longer the first choice for digital camera applications. Today, lithium-ion (Li-ion) and nickel metal hydride (NiMH) are the typical rechargeable formulations, while oxy nickel hydroxide (Oxyride) and lithium dominate the disposable category.

The kind of battery your camera uses is generally predetermined; in most cases, you don’t have many options. For example, if your camera uses a proprietary lithium-ion cell, your choices are limited. On the other hand, if your camera uses AA cells, you have lots of flexibility. Several of the best-selling compact camera models, as well as power grips for high-end D-SLRs, use AA cells—and for good reason. The batteries are inexpensive and are readily available almost everywhere in the world. Equally important, they have already been vetted—it’s far more efficient for a manufacturer to adopt a known commodity than to do exhaustive testing of a new technology.