Preventing Cargo Trailer Lights From Draining Vehicle Battery

Question:

Hello so I am wondering if my cargo trailer interior lights will drain a tow vehicle battery if I add a auxiliary battery to the trailer? Normally the vehicle has to be on to power the cargo trailers interior lights so thinking of adding a auxiliary battery to be able to have the lights on for a short time while the truck is off and want to k ow if the trucks battery will be depleated as well

asked by: Josh W

Expert Reply:

If the 12V power for the 7-Way connector is active it will pull power when the vehicle is off and installing a Battery Isolation Solenoid # PK5231201 would definitely help you avoid this situation and keep your cargo trailer interior lights running from the auxiliary battery only. The battery isolation solenoid will shut off the 12-volt feed from your vehicle battery to 12-volt accessories on your trailer when the ignition is turned off. This lets you run the trailer's electrical components without draining your battery.

Another backup option for your auxiliary battery is a charger like part # CTEK56158 to charge the battery when land power is available. This would make sure your towing vehicle battery stays charged when you need it.

expert reply by: Patrick R