That's why we're not surprised to learn that the AA batteries that ship with the charger come from a 3rd party. The folks at the website SuperApple have gone through the trouble (translation) of tearing them down. This is certainly the first AA battery teardown we've ever seen. What they found was that they're a near perfect match, both in construction and performance, to the Sanyo Eneloop HR-3UTG.
That's good news, as Engadget recently raved over those little buggers, claiming that they retained 70% of a charge after 3 years in a drawer. While it isn't news that Apple is using batteries not manufactured by their employee's hands, it's good to know that said batteries are of high quality.