How to Prevent Winch Battery From Charging Breakaway Battery When Unplugged from Trailer

Question:

I have a breakaway brake system on my trailer with the battery testing unit thing whenever it is connected to my truck the amber led on the breakaway unit is lit. I just installed a winch with a deep cycle battery I and hooked it up to the 12v circuit from my 7pin to maintain/slightly charge the deep cycle while its being towed. My problem is with how its wired the winch battery is putting power to the breakaway system and the yellow led is constantly lit how can I have them both charge and stay seperate so without a switch

asked by: Richard S

Expert Reply:

If two batteries are connected to each other they will both try to equalize in terms of voltage. The higher voltage battery will charge the lower battery.

What you will need is a diode to install on your 12 volt accessory circuit like # RM-790 after the 12 volt circuit runs to your breakaway charger and between the battery for the winch. A diode would prevent the voltage of the winch battery from backfeeding to the breakaway battery.

expert reply by: Jameson C