You probably don't want to use my method but here it is anyway!
I run a # 1 or #2 positive battery cable from my trucks dual batteries all the way to the back & have installed a "NASCAR" quick disconnect battery plug (175 amp, I believe they are originally used in marine applications) on the underside of the rear bumper. The negative cable is just a foot or two long attached to the frame in the rear of the truck. I put the relay pack supplied with the winch in the cable under the hood to keep it out of the weather. I then put another NASCAR plug on the trailer. When you have trucks with dual batteries, there is no need for a heavy battery in or on the trailers
Both trucks have this setup to accommodate both trailers (open & enclosed) In the enclosed trailer, those cables also power the lift leg on the front of the trailer, as well as my inverted that is used for my 8ft dual bulb AC lights & my compressor to air up tires. For the open trailer, the winch is in the "V" shaped tool box on the front to keep it out of the weather.
God bless
Bill
https://www.jalopyjournal.com/forum/...closed.614419/