I just went back over my post and i said the coach battery was what went bad. It was the chassis battery that melted down.The one that starts the v10 engine. It was about 2 years old. I was plugged in to shore power and the only thing running was the heat pump. Could this be a random bad battery malfunction or could something be wrong somewhere. Nothing has changed or different. We have done this many times before. Sorry for the confusion, but would really like some replies as to what to do.
The chassis battery? Most chassis batteries do not charge off the converter/charger and yours shouldn't have.
It sounds like you probably have a bad battery isolator or solenoid. Usually, these will allow current to flow only one way so your engine/chassis generator will charge both the coach and chassis batteries while traveling. A stuck "emergency start" switch could cause this as well.
To see if that battery is cooked, you need to remove from the vehicle, charge it with your external charger, and check each cell with a hygrometer. Remove the caps from the cells while charging it. If you see a lot of boiling or bubbline on some cells, and none on others, it's pretty sure sign you have shorted plates as well.
All of that aside, the charging/battery isolation problem needs to be sorted out.
2005 31' Coachmen Freelander 3150SS, Stargazer II - Mobile Astronomy Unit Do you remember when the sky was dark, and the stars were bright? The International Dark-Sky Association American by birth...Scottish by the Grace Of God.