I've noticed that when I travel with the Mophie, the battery drains incredibly quickly even when I'm not doing anything on the phone. Today was really ridiculous. I went to dinner with around 30% battery, left after 3 hours and my phone was dead! I'm wondering if anyone else has seen this problem. I speculate it's because the case is interfering with reception and causing the iPhone to have to transmit with higher power. But who really knows?