How to Charge a Trailer Battery Using a 4-Way Trailer Connector

Published 08/31/2018

Products Featured in This Question

Wiring Kit for Hydrastar Electric Over Hydraulic Actuators

(12)

$83.69

Redarc In-Vehicle BCDC Battery Charger - Dual Input - DC to DC - 12V/24V - 40 Amp

(87)

$620.00

Question:

I have a 7 way plug on my truck. the trailer is a flat 4 wire. I use the adapter 7 way to flat 4 to get trailer lights to work. my question I want to charge a battery on the trailer . whats the best way? should I use the side marker lights to charge the battery or is there an adapter or a simpler way

asked by: Aaron

Expert Reply:

The best way to maintenance charge the 12 volt auxiliary battery on your trailer would be to upgrade to a 7-way trailer connector. For this, I recommend using the Trailer Wiring 7-Way Upgrade Kit part # HS381-9000. The 12 volt hot lead (black wire) that feeds into the trailer connector will need to connected to the positive post on the battery and will work to provide a maintenance charge. However, if you need to provide an actual charge then you will need to use a battery charger instead like the Redarc BCDC Dual Battery Charger part # 331-BCDC1240D.

expert reply by: Conner L