What every best Batteries has:
- Long shelf life.
- For rechargeables, short charging time.
- Long life.
Testers at TheWirecutter.com put six types of rechargeable AA batteries and four brands of AAAs through (ahem) a battery of tests. They spend over 1,000 hours measuring capacity with a battery analyzer and 20 hours testing batteries with headlamps, flashlights, and a high-powered RC car. They also charge up four batteries from each brand and set them aside for nine months to evaluate their shelf life. They name two top picks for AA batteries but say AAAs all perform much the same.
ConsumerReports.org's editors test 13 brands of alkaline AA batteries and two brands of lithium AA batteries, measuring how long each one lasts in a toy and in a flashlight. Lithium batteries outlast most alkalines, but they cost around twice as much. The editors recommend lithium batteries for high-drain devices and alkalines for low-drain ones. Rechargeable batteries and sizes other than AA are not tested. One of the recommended brands is now discontinued.
BitBox Ltd., a British electronics company, tests over 50 brands of disposable AA batteries. Using a specially constructed rig that drains the batteries at a steady rate, they test each battery under high and low current. Lithium batteries perform the best overall, but they cost more per ampere-hour than alkalines. Among alkaline batteries, well-known brands like Energizer and Duracell fare no better than store brands from Costco and Ikea.
Michael Bluejay is an energy expert who has been interviewed in Newsweek and on NPR. His comprehensive guide to batteries names the best types for a wide variety of uses, from smoke detectors to cameras. Bluejay recommends low self-discharge (LSD) rechargeable batteries for most purposes. His favorite AA rechargeable battery, the Powerex Imedion, is now discontinued, but he also says Eneloop Pro batteries combine high capacity, lots of charge cycles, and a long shelf life.
Electronics enthusiast Stefan Vorkoetter tests 13 brands of LSD rechargeable batteries to see how well they hold their charge during storage. He measures each battery's power right out of the package, after a full charge, one week after charging, and seven weeks after charging. He doesn't test the batteries' performance during actual use, however.
Choice, an Australian publication that's similar to ConsumerReports.org, tests rechargeable batteries under laboratory conditions. Editors put 12 NiMH batteries through 200 cycles of charging and discharging and measure their life cycle, time to discharge, and how fast they lose their charge in storage. In a separate test of 25 disposable batteries, editors measure performance and endurance under high-drain and low-drain conditions. Most of the batteries in both tests are not available in the U.S., but a handful are.
You can find just about any type and brand of batteries at Amazon.com. In fact, there are so many brands here, in so many sizes and quantities, that it's difficult to compare them. To simplify our search, we looked only at AA batteries that had high overall ratings. We found six rechargeable batteries, and six single-use ones, that had overall ratings of at least 4.5 stars from 1,500 users or more.
A team of students at Worcester Polytechnic Institute tests a variety of AA batteries for DealNews.com. Testers measure each battery's initial voltage, use it for 19 straight hours, and then check to see how much voltage remains. All the alkaline batteries, from Duracell and Energizer to cheap generics, perform pretty much the same. Energizer Advanced Lithium batteries retain much more power, but they're also pricier, and their high initial voltage could damage sensitive devices.