Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
It doesn't mention AA batteries on your link. :confused:

Flexible recharging system: Recharge your mouse using a flexible micro-USB system through your computer or a standard wall outlet—even while you’re using it. You’ll always have the power you need to get the job done.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.