I did a battery pull due to phone freezing, I tried to reboot and the phone would not reboot. I then plugged into a charger and the Motorla "M" icon appeared and a strange battery icon I have never seen. It was animated, went from 0%, to 60% and 100%. The animation was like liquid inside the battery filling up. About 15 minutes later it rebooted and turned on.
Today (about 3 days later) it happened again and it's been on the charger for a while and nothing.