I left my Garmin 478 on my bike for the last few days. Not on, but just plugged in where it will charge. Somehow, this drained my PC680, bought in Sept of 2012, to the point where it wouldn't start my bike this morning. Wasn't dead, in that dash lights would come on, but rat-tat-tat-tat-tat when I tried to start. I tried hooking up the Sears 2A/4A auto charger I have, and it just kept saying "check battery"....would never go into charging mode. Any ideas? Different charger? I'm kind of shocked that the trickle charging from a GPS would kill the fabled Odyssey battery.