Winn L. Rosch Hardware Bible, Sixth Edition

Power

Digital cameras are electronic devices and consequently need a steady supply of electricity. With today's technologies, their needs border on the prodigious and often sneak to the far side of the border. That power has to come from somewhere, and the places of choice are two—from self-contained batteries or from utility-supplied electricity through an external transformer, the ubiquitous power brick.

Batteries

Unlike camcorders, the batteries for most digital cameras are standard sizes. Most digital cameras use standard AA or AAA batteries, typically about four (the number needed to get enough voltage for conventional logic circuits). Most manufacturers generously include batteries with their products.

Digital cameras are high-current devices. ...