Will the Brakeaway Battery Backfeed into My Tow Vehicles Battery?

Question:

Hi, I have a small trailer and a Tesla. The 7 pin connector on the Tesla powers lights on the trailer, but the brake appears to be powered by an onboard battery on the trailer itself. My question is, how do I make sure that any battery on board the trailer doesnt back feed into the Tesla battery. How can I isolate the two batteries or at least make sure that power flows only one direction, from the Tesla to the trailer?

asked by: S W

Expert Reply:

I believe you are talking about the brakeaway switch on your trailer such as the Hopkins # 20400. The only occurrence when that battery backfeeds into the Tesla battery is if the pin is pulled in the event of the brakeaway. If that pin is not pulled on the brakeaway switch, there will not be any feeding into your Tesla's battery.

If you are still concerned, you can always install the Roadmaster Hy-Power Diode - (Qty 1) # RM-790 so that it is impossible for the current to backfeed into your battery. To install this, you need to splice into the 12v and splice the side going into the front of the vehicle on the input side and the side going back to the vehicle on the diode's output side.

expert reply by: Bob C