Originally Posted by gmc
What he said... lol...
The power for lights for the toad comes from the RV wiring harness...
The brake system has to be wired into the toad's battery for breakaway.
Like the U.S. Gear System, Roadmaster's Invisibrake also has its own vacuum pump (to use the toad's power brakes rather than dead pedal) - and also handles the charging of the toad battery from the RV.
Seems newer Blue Ox Patriot (portable) systems now come with their own on board battery. Haven't heard how long they last - or if they are charged from RV...
I'm running the patriot for 2 years now. Has its own battery but is backed up by the toad battery via 12 acc plug. I use a constant hot in my glove box. I've towed for 12 hours straight without starting toad and haven't had any issues.