Last year I began to have a lot of issues with miaomiao unable to connect to phone for hours, or connecting and disconnecting after a short time. Eventually gave up and bought miaomiao 2, but left version 1 lying on the side. The other night I heard a noise and the front of miaomiao 1 and the battery were on the floor, with the back still in the original place. It wasn't in the sun, and the room wasn't particularly hot. Just glad I wasn't wearing it at the time!!