I have an 81 Odyssey. The battery box is empty except for dangling wiring that has been cut at some point and then wrapped up with electrical tape. I have no idea why or when. But I would like to restore the wiring to use a cabin battery and of course my appliances when we are off the grid. The interior lighting and appliances do function when hooked up to the 120VAC grid. I want to make sure that the new cabin battery is correctly installed and that it can be charged off the alternator when driving. Can you help me with diagrams, specific or generic, or an explanation of how the circuit should look? Thanks, Leroy