Many digital cameras use AA alkaline or AA rechargeable batteries for their power source while others use proprietary rechargeable batteries. As with everything in photography, there are advantages and disadvantages to each option. When you buy a camera, the way a camera is powered should be included in your consideration.
Disposables don't require managing. Here are some of the pros:
AA alkaline disposable batteries are available everywhere.
They are generally inexpensive.
If you carry around plenty of extras, you will never be caught short without a fully charged power supply.
You can use them in other devices you have, such as a flash, that require AA alkaline batteries.
Disposables can be a nuisance to deal with:
Good rechargeable batteries will not have to be switched as often as AA alkalines.
In cold weather, alkaline batteries will die right away.
You will have to constantly buy and stock dozens of AA batteries to make sure you have enough ready power.
Rechargeables may be much cheaper in the long run, although they do not last indefinitely.
Batteries are rated with an mAh (milliamp hour) rating. The higher the rating, the longer you can use the batteries. For example, rechargeables are typically available from 700 mAh to 2,700 mAh. To determine how long a battery will last, divide the mAh by the electrical demand of the camera or device.
You can save a lot of money with AA disposables if you know how.
You can pay as little as 25 cents per battery or as much as a dollar per battery depending on what brand you buy, where you buy them, and how many you buy.
Buy AA alkaline batteries in bulk because they are much cheaper that way; consider buying twenty or more at a time.
Lesser-known brands such as Panasonic work just as well as better-known and highly advertised brands; these are often available at Dollar Stores.
Buying AA alkalines at convenience stores or other such places will cost you an arm and a leg — a dollar or more a battery — yet in an emergency it is nice to know that you can find them anywhere, anytime.
Battery technology has advanced quite a bit. Rechargeables now claim that they last much longer than AA disposables and that the batteries can be recharged up to 1,000 times. Some manufacturers claim batteries can be recharged quickly, in as little as an hour. You can expect to pay as much as five dollars per battery. However, if you use your camera a lot, the savings over several years could be hundreds of dollars.
With rechargeables you will not have to carry around as many batteries or buy batteries very often. However, you will need to keep your batteries recharged. This requires management; you will need a system so that you know which batteries are dead and which are recharged and you will need to take your recharging device with you.
Also keep in mind these requirements for rechargeables:
Always charge up your new rechargeable batteries before you use them the first time.
Your recharger must be compatible with the size of battery and the type of battery you have.
If you are not going to use batteries for a while, give them a full charge before storing them.