Can a Trailer Battery On a Dump Trailer Be Charged Using The 7-Way Trailer Connector

Question:

When we try to charge our deep cycle battery by trickle charging it burns up our harnesses. How can we keep that from happening?

asked by: Jeff

Expert Reply:

First, a trailer battery cannot be charged up from the 12 volt circuit on a 7-Way connector. The 7-Way can only provide a maintenance charge which will keep the battery at is current charge level. It is possible that the battery is back feeding when the truck is turned off and the trailer is still connected.

You may also need to increase the size of the wiring. Wiring that is too small a gauge may not be able to handle the power draw. A short circuit or corrosion in the trailer connectors could also be a concern. Clean out the connectors, front and back, and make sure the 12 volt circuit wiring is show bare wire and rubbing against something metal.

The battery may already be fully charged and adding any additional current is actually overcharging the battery. You should have the battery tested locally to determine if the battery is still good.

Then, I recommend disconnecting the battery from the 12 volt circuit on the 7-Way and using a regular battery charger like # CTEK56353, to charge and maintain the battery. Unlike trickle chargers, this charger will not overcharge the battery.

expert reply by: Michael H