Got a question about a winch i am installing on my car trailer. I trying to set up the winch so it can be removed from the trailer and i want to use a battery on the trailer to power the winch. Looking and reading a few articles it appears i can use either a deep cycle marine battery or maybe a garden tractor battery. My question is about charging the battery, i have a 7 pin plug on the back of the truck and from the trailer, it has 1 hot wire that doesn't go to anything, it's just a spare i guess. Could i use that wire and run like a 10 gauge wire from the plug to the battery and use it to charge the battery? I'm not sure if a hot wire just being hot will actually charge the battery or not. Can't really find anyone that has done this, so i am hoping that someone here may have used a battery on the trailer before.