It was a joke (about the battery).I hadn't updated to 4.1, was still on 4.0. Just tried it, and it opens up a menu that had 3 options: Update the system, Initialize data (without deleting saves) and Initialize System (deletes everything). I just updated from there. I didn't notice it doing anything funny with the battery though.
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You have to hit reboot and then hold the vol-, vol+ and power/sleep button until the maintenance menu appears.
I wonder if they finally added support for Bluetooth headphones.