Following up from the USB battery articles I wrote for Reviewed.com is this review of AA rechargeable batteries. Bottom line: most were pretty good but there was a surprising amount of variation.
After hours of testing, we chose the Energizer Recharge Universal (available at Amazon for $20.99) as our best rechargeable batteries. They provide the best balance of capacity and price, holding about 2200 mAh of charge and supporting up to 1000 charge cycles…For a less expensive alternative, we recommend AmazonBasic Rechargeable Batteries (available at Amazon). Each individual cell holds about 1800 mAh of charge so your devices won’t run for as long as they would with the Energizers or other higher capacity batteries.