I have a weekday alarm to wake me up in the mornings. The past 2 nights, I've forgotten to take my phone with me upstairs so it has stayed and obviously the alarm has gone off on its own. Yesterday morning the phone was dead which was to be expected because my battery was kinda low. I fully charge the phone yesterday and didn't talk on it a whole bunch. This morning, same thing happened yet again. And the phone acts like the battery has been fully drained. Any explanations?