All digital cameras get their power from batteries. So if you're shopping for a digital camera it's important to know the battery options that are available so you can decide which will best meet your picture-taking needs. Also, as a non-working battery will turn even the most capable digital camera into a paperweight, it's essential to maintain your batteries properly so your camera will be available when you need it.
Types of Batteries
Digital cameras use two general types of batteries, lithium-ion and AA. Most cameras can use one or the other, but not both. Either can work well and be a dependable source of power.
The majority of digital cameras use rechargeable lithium-ion batteries. They are good for small cameras because they can be made thin and lightweight, provide good power, drain slowly and can be recharged. They are especially useful for ultra-compact cameras, where very small size and light weight are a priority.
Most lithium-ion batteries last for 150-350 pictures before they need to be recharged. Lithium-ion batteries are also used to power larger, more expensive DSLRs (digital single lens reflex cameras). These batteries cost more than the lithium-ion batteries in smaller cameras, but have much more power and can provide for well over 500 shots between charges. Keep in mind that battery life will be less if the user spends time accessing the camera's menu, shooting videos or using the camera's special shooting modes that involve taking multiple shots.
Until a few years ago, AA batteries were the most common battery type for digital cameras. Today they are found mainly in lower cost cameras, although they are sometimes present in larger, more costly cameras.
There are several different types of AA batteries used in digital cameras. The least expensive are non-rechargeable alkaline batteries. While they are convenient, as they can be purchased everywhere, they will not last long in your camera, so they are probably best saved for emergencies. In recent years, non-rechargeable lithium AA batteries have become available. While they are more expensive than the alkaline type, they have more power and last much longer.
Another type of AA batteries are rechargeable NiMH (nickel metal hydride). Although they have good power, are long-lived and can be recharged numerous times, they will lose their charge relatively quickly when the camera is not being used. Low-discharge NiMH rechargeable batteries are much better at maintaining their charge, though they tend to have less power than regular NiMH rechargeable batteries. As is the case with lithium-ion batteries, battery life will vary depending on how the camera is used.
Maintaining your Batteries
It's a good idea to have a full battery charge before taking your camera out for shooting so you don't miss that important picture or video. Remember, all batteries will eventually drain when not used. If your battery (or batteries) is rechargeable, keep in mind how long it will take to fully charge. Recharging time can be as short as 45 minutes or as long as 10 hours, depending on the battery and charger. If you are going to be shooting extensively, it's a good idea to bring along a second, fully charged lithium-ion battery, or several, fully charged AA batteries.
Finally, if you're not using your camera for a lengthy period of time (longer than a month), it's best to remove the battery (or batteries) to ensure the safety of your camera.