Are Diodes Needed to Separate 2 Trailer Batteries Charged by the Same 12 Volt Circuit

Question:

The instructions say to splice the black wire on Break-Away box to trailer 12 volt auxiliary power lead.This will charge the Break Away battery when vehicle is in use. However,I already have the auxiliary power wire hooked up to the house battery that powers my interior lights. Is it okay to connect both batteries to the same wire,or do I need something else like a diode or something? Thanks.

asked by: DARYL B

Expert Reply:

I do recommend installing diodes on the wires going to each of the batteries so that the power can only flow in one direction (to the batteries) and not back feed to each other. You would just need 2 of diode # RM-690.

expert reply by: Michael H