theoldwizard1 wrote:
The only way you will ever be able to maintain/charge a "toad" battery is with a DC-DC charger. Have it permanently mounted in the toad, close to the battery. You can pick up B+ from the tow vehicle via the standard 7 pin connector.
You need to be ABSOLUTELY CERTAIN that B+ from the tow vehicle does NOT connect to B+ of the toad ! Thus way require some relays to keep these two systems isolated ! Using separate brake/turn signal lamps is a good first step !!
I was considering a dedicated charge wire from the MH battery to the car battery with a connector and a fuse in line next to the battery. That seems to be the easiest and least complicated approach.