Czech website SuperApple (via Engadget) did extensive testing of Apple's new batteries, and found that they have many of the same characteristics as the Sanyo Eneloop model HR-3UTG batteries. In addition to having identical performance, the Sanyo rechargeables also have the same minimum capacity of 1900 mAh.
The website also took apart one of the AA batteries from Apple, but did not find any evidence on the inside that they are manufactured by Sanyo. The Apple-branded charger, which re-powers two batteries at a time,was also taken apart and found to have a "startling" amount of unused space inside.
As noted in AppleInsider's first look at the new Apple Battery Charger and AAs, the batteries do not have an Apple logo on them. Instead, they feature a plain silver design that simply reads "Rechargeable."
In fact, the only mention of Apple on the battery is in the fine print: "Charge only with Apple specified charger. Made in Japan." Sanyo's corporate headquarters is in Osaka, Japan, and its Eneloop batteries are said to be manufactured in both Japan and China.
Apple has not commented on who manufactures its batteries, but the included charger does carry the traditional "Designed by Apple in California" fine print.
In all, users get 6 AA batteries and a charger for $29. For comparison, a Sanyo Eneloop four-pack of batteries with a charger that can recharge four batteries at a time retails for $21.99.