My 5th wheel does not power off of my vehicle when connected to it. A couple of times after it has set for a period of time, with no power connected to it, the 12V battery needs an assist to get the f...
It could be something like this Battery pack Some shops use a large battery fixed to a hand truck. I carry one of the battery packs in each of my vehicles for winter use and on the road for emergencies. Not only for me, but for others that have difficulties. Harbor Freight quite often have them for less then $40.