I saw this today when the cover was off. It doesnt have to do with the battery i dont believe becuase the phone still works when its off. The phone didnt come up with any notifications either. There are conectors that match them on the phone as well. Any ideas gentlemen and ladies?
Good point. I thought the back has an rfid-like tag that can be read by another phone's near field. I was only guessing that the phone powers the pen by the magnetic near field via magnetic induction and communicates using NFC. Only a guess.