According to my battery graph the phone went from 85% to 0 in an instant. I wanted to add a screenshot, but I do not have enough reputation. The last time I checked it was nearly full, and 7 hours later in the morning it was empty. At home I charged it until it showed 29 percent, but by the time I got to the office, it was 32.
How can this be? How can I prevent it in the future?
LG P990, Android 4.0