I use genuine Garmin rechargeable batteries, and I have never had a problem with my GPS Today, wanting to ensure my battery did not die while skidooing, I plugged a 12volt usb adapter into the skidoo outlet, and using a genuine Garmin cable plugged into my Garmin. My Garmin did not turn on, and it has not turned on since. I have tried new batteries, I have tried all resets. Ultimately it appears my 64s is dead. Has anyone else every encountered this My suspicion is a surge from the charging outlet, but I would has assumed the batteries would have taken the overload, vs hurting something in the unit itself. Any thoughts or feedback would be appreciated,