Last week I went up to New Hampshire in an area where I had barely any reception. My battery would come pretty close to dying in about a day, so I would have to charge every night. Now that I'm back at home, my phone is still acting like it did last week. I'm at 48 minutes of usage / 5 hours 29 minutes of standby, and my battery is at 75%. Usually at this point, it's barely gone down at all. What's the deal?