Would Charging Vehicle Battery While being Flat Towed Cause RV Battery to Drain Toad Battery

Updated 02/15/2016 | Published 02/14/2016

Question:

I have set up my HHR for towing and would like to run a line from my RV to charge this. My RV is wired through the seven pin plug with a wire to do this. It is only on when the ignition is on. My concern is will the RV draw from the battery of the towed HHR. Should I put a diode in line to prevent this? If so what one should I use? Thank you

asked by: Phil P

Expert Reply:

If you ran a wire from the 12 volt accessory circuit of the 7-way on your RV to the positive post of your RV would not end up drawing from the HHR. Since the alternator of your RV would be keeping the charging system of the vehicle with higher voltage than the battery of the HHR the voltage would only be going to the HHR battery while flat towing.

A diode would not be necessary.

expert reply by: Jameson C