I recently traveled overseas. I powered off my fully charged phone before boarding the plane. When I arrived and turned on my phone some 18 or so hours later, the battery was practically dead. I couldn't do a think before recharging. This happened again on my way home. I needed to charge my phone upon arrival before I could call my husband to coordinate being picked up. Is this normal? I've only had my phone for a little over 2 months and don't know if this normal or a problem with the phone.