Digital Camera Batteries
One of the most important items in digital photography is the battery. Since most cameras, camcorders and other accessories use batteries as their source of power they are useless without batteries or with dead ones. Make sure you always have an adequate supply of batteries with you as you may miss the photographic opportunity of a lifetime if you can't operate the camera. You can get a lot of photos from a single battery, but it will drain quickly. Most digital cameras use standard batteries, but others use proprietary batteries only, which are made by the camera's manufacturer. Some cameras can use both, but you shouldn't mix different types.
Most batteries are rechargeable so it's a good idea to get yourself a charger to save money. Rechargeable batteries come in three basic types: NiCD, NiMH and Lithium-Ion. Nickel metal hydride (NiMH) is the most popular as they have more capacity than NiCD and don't suffer from memory effect. They may lose some charge when not used so make sure you recharge them before using. Rechargeable batteries don't last forever though, and need to be replaced after about 500 - 1000 charges.
Remember other countries use different electrical systems, so you may need to take an adaptor with you to charge your battery somewhere else.
Batteries generally range in price from about $20 to $100.