How to Charge Trailer From Secondary Battery with Isolator

Updated 08/22/2017 | Published 08/19/2017

Question:

Im looking for kind of an obscure answer I cant seem to find. I have a 2010 Suburban for towing my 30foot travel trailer. My travel trailer has two 12v batteries in parallel, and Im looking to charge them via the 7-pin trailer connector. However, I also have a dual battery setup with a battery isolator, and my secondary battery is a deep-cycle. Im looking to charge my trailer via my secondary battery, but without draining my primary battery. Is there a way to convert the Stud A, which gives power to the 12v pin in the connector, to receive power from my secondary battery only?

asked by: Ian

Expert Reply:

It sounds like you currently have an isolator like the Deka # DW08771 installed between your primary and secondary battery on the trailer. If this is the case, then running a 12V wire from the 7-Way connector to the secondary battery positive post should give you exactly what you are looking for.

I have included a diagram that might help with the wiring for this setup.

expert reply by: Chris R