I have an 18+3 Hudson deck over trailer rated 10000 # payload. It has two axles with brakes on both axles. It uses a small motorcycle battery for the break away system. I have added a 9k winch and a deep cycle RV battery to power the winch. The trailer gets used intermittently and the motorcycle batteries do not last long. I would like to eliminate the motorcycle battery and power both the winch and breakaway from the RV battery. Right now I charge the RV battery with a charger, it is not wired to the trailer wiring. My initial thought is to wire an alternator diode and a 30 amp circuit breaker in the line between the RV positive terminal and the trailer 12v hot wire. That would prevent the RV battery from ever feeding power back to the truck electrical system. Have any of you guys done this setup and do you have any advice or see anything wrong with my proposed setup?