All my trucks have been wired that charging wire is hot only with ignition on. That prevents truck battery discharge by camper/trailer.
On one truck PO replaced fuse with automatic 30 amp breaker. I guess he was having pretty good draw there.
Also my converter is lousy way to recharge deeply discharged batteries.
At higher draw it will overheat and shut off for some time.
I did wonder why 1 hr of generator running did not recharge batteries too much till I notice that. Now I take computerized 25 amp charger with me.
