My Forerunner 55 completely drains over night even though it was almost fully charged the day before. I've noticed this tends to be after I've done a pool swim that day. I often wake up and realise I have to unexpectedly charge it before going for a run. It seems to last ages if I'm just running but if I swim, it is almost guaranteed to drain and turn off overnight. Has anyone else had this problem or know if there's a fix? Thanks!