Nimh Rechargeable Battery

The sleek, compact Apple Battery Charger is all about efficient charging. It's optimized for Apple-supplied batteries, but it works with AA NiMH batteries from other companies, too. And with a feature that automatically reduces its power intake once your batteries are fully charged, the Apple Battery Charger is one of the most energy-efficient rechargeable battery solutions available.
Each Apple Battery Charger comes with six NiMH batteries — two for your keyboard, two for your mouse or trackpad, and two for charging. Not only do these high-performance batteries have up to a 10-year lifespan1, they also hold a charge for an incredibly long time. So you always have power when you need it.