How to Charge Trailer Battery with Power from Trailer Connector Socket

Updated 09/07/2017 | Published 09/05/2017

Question:

How do I wire a trailer mounted winch to a separate trailer mounted battery and tend the battery through a 7 way trailer connector on my tow vehicle? Which pin is the auxiliary battery tending pin? My tow vehicle is a 2017 Super Duty Diesel with dual batteries and upfitter switches.

asked by: Mateyo

Expert Reply:

On your trailer's 7-way the pin in the 1:00 position is the 12 volt power circuit and would be what you'd want to run to your trailer battery. Basically this circuit would get ran to the positive terminal of your trailer's winch battery and it would help keep it topped off when you're towing. It wouldn't be able to recharge a dead battery though. I'd recommend 10 gauge wire for this like part # 10-1-1 which is sold by the foot.

Then your winch would get powered off of that battery by running to it's positive and negative terminals.

expert reply by: Jameson C