For powering high-drain electronics such as digital cameras, the most efficient batteries to use are high-capacity Nickel Metal Hydride (NiMH) cells. Higher capacity batteries store more charge and they can power your devices longer.
The highest capacity rechargeable AA batteries are: Ansmann’s 2850 mAh batteries and Powerex’s 2700 mAh batteries. Of these two batteries, Powerex’s 2700 mAh gets the most positive reviews from photographers. It received an average of 4 out 5 stars from 98+ reviewers on Amazon.
If you need batteries that hold their charge for an extended period (3 months or more), you should try the
“low self-discharge” batteries — see our review here.