decaturbob
Well-known member
negative (ground) is electrically the same right? I haven't verified, doesn't make sense if one was isolated from the other from the chassis. The pain of having zero electrical diagrams
The coach battery was grounded by the company that built the chassis. The house battery ws grounded by the company that built the coach. Two different companies who are not in communication with each other. But they both go to the same place so all is good.Bobtop46 said:True, but on my coach (no diagram, traced the cables) the engine battery is grounded to the engine block. The coach battery and the rest of the 12v system is grounded to a stud on the frame near the battery bay, even though both sets of batteries are nearly side by side.
Lou Schneider said:You need to worry about the positive sides of both batteries interacting with each other. You'll either need a charge controller with two isolated outputs, or an isolator after the controller to provide two outputs. You don't want to connect both sets of batteries to a common point.
If you tie the positive sides of both batteries together, you create a bridge between them and they'll both discharge when the solar panel isn't charging them.
More to the point, unless you put a fuse appropriate to the wire size at both batteries, you risk a short circuit or a heavy draw like an inverter or the starter motor overloading the interconnecting wires and creating a very real risk of a fire.
Lou Schneider said:You need to worry about the positive sides of both batteries interacting with each other. You'll either need a charge controller with two isolated outputs, or an isolator after the controller to provide two outputs. You don't want to connect both sets of batteries to a common point.
If you tie the positive sides of both batteries together, you create a bridge between them and they'll both discharge when the solar panel isn't charging them.
More to the point, unless you put a fuse appropriate to the wire size at both batteries, you risk a short circuit or a heavy draw like an inverter or the starter motor overloading the interconnecting wires and creating a very real risk of a fire.
John From Detroit said:On most all american made vehicles yes. NEgative is connected direct to chassis ground.
NOW.. Not all vehicles are AMERICAN MADE.. Sherlock Holmes (The fictional British Detective) and I both drove the same make and model for a while.. IT Was NOT Negative ground (English Ford) But for US built it's been negative ground as long as I can recall.
(Fun with that car. I eventually "Flipped" the electrical system)