Will Towing Vehicle Provide Charge To Trailer Battery Through Trailer Connector

Updated 11/10/2015 | Published 11/09/2015

Question:

I installed a 4 pin connector on my truck C55379 and later added a brake controller and a 7 pin UTBC 7. This was all to tow a camper trailer, a vintage trailer I am restoring and wired myself. I have checked that all my connectors are working properly and the 12VDC hot lead is powering all of my lights and appliances just fine. Im going to be installing the battery soon. I am wondering about charging the battery. If I simply run a duplex cable from my junction box to the battery I understand my 12VDC circuit will be powered. Will the battery on my trailer also charge while its connected to my truck? I have seen that one needs a solenoid to prevent the trailer/battery from draining the truck battery while the ignition is off. If I just dont use the trailer appliances or lights before disconnecting the trailer from the truck I should be good, right? Eventually Ill be getting a trickle charger to plug into my 110VAC circuit. Im just trying to figure out if the battery will charge without additional equipment. Thanks,

asked by: David H

Expert Reply:

The battery on the trailer will not charge if it is attached to the 12V power wire from the towing vehicle. It will provide a small amount of current that helps maintain the current charge of the trailer battery.

I recommend using a battery charger like the CTEK MULTI US 7002 12-Volt Universal Battery Charger, part # CTEK56353. This charger features pulse maintenance and will not overcharge the battery like many of the common chargers do.

expert reply by: Jeffrey L