Can Dual Battery Setup of Trailer Wiring be Disconnected When Towing

Updated 06/06/2022 | Published 06/02/2022

Question:

I have a travel trailer that has 2 12V batteries in parallel. My question is do both batteries have to be attached while traveling and does having two batteries drained the battery of the toe vehicle?

asked by: Michael J

Helpful Expert Reply:

In order for both batteries to charge while you are traveling both batteries would have to be connected. You can have one or both batteries disconnected though and the rest of the trailer taillight wiring will still function.

A parallel battery setup would not drain the tow vehicle battery when towing. The alternator would easily be able to provide enough amperage. If you left the trailer connected when the vehicle is off the batteries would slowly discharge though.

expert reply by: Jameson C