Does Battery Charge Kit from Towed Vehicle Have Potential to Damage Tow Vehicle Battery

Published 12/17/2023

Question:

Going to pull a 2015 xterra behind my 2005 f350 when I have the camper on. Want to run a wire from the existing trailer charge wire in the ford trailer plug to charge the batteries on the xterra while towing it, with out a diode or isolator wont the towed vehicle battery back feed into the truck and up the voltage and cuase damage to the electrical system?

asked by: Kevin

Expert Reply:

The Roadmaster Battery Charge Line Kit part # RM-156-25 would be the kit you would need to charge the battery of your 2015 Nissan Xterra when it is being flat towed. This type of charge setup does not require a diode nor does it have potential to damage either battery. Worst case scenario is the towed vehicle battery might get drained or charged from/by the tow vehicle which is totally safe and normal. Basically the batteries when connected will seek to equalize to each other so whichever one has the higher voltage will charge the other one.

expert reply by: Jameson C