Breakaway System Kept Trailer Brakes On and Melted Wiring

Published 06/22/2018

Products Featured in This Question

Hopkins Engager Trailer Breakaway Kit w/ Charger, LED Tester, Hardware, and 5 Ah Battery - Top Load

(746)

$72.04

Question:

I JUST BOUGHT A 5TH WHEEL AND DISCONNECTED AT OUR DESTINATION AND FORGOT TO RELEASE THE BREAKAWAY CABLE PULLING THE PIN ON THE BREAKAWAY. THE WIRING BY THE 2 BATTERIES LITERALLY MELTED DOWN CAUSING A VERY CONCERNING SITUATION. THE DEALER IS TELLING ME THAT IF THE PIN IS NOT PUT BACK WITHIN AN HOUR THAT IT WILL CAUSE THIS TO HAPPEN. I FIND THIS SAFETY FEATURE TO BE GREAT BUT IF THIS IS TRUE ITS LIKE PULLING THE PIN FROM A GRENADE AND IT EXPLODING AFTER AN HOUR WITHOUT THE PIN BEING PUT BACK INTO THE GRENADE. I HAD TO UNHOOK THE CABLES FROM THE 2 BATTERIES THAT POWER THE TRAILER TO GET IT TO STOP COMBINED WITH A FIRE EXTINQUISHER. IS THIS NORMAL? THEY ARE TELLING ME THAT IT IS A COMMON THING WITH ALL TRAILERS? REALLY?

asked by: TIM W

Expert Reply:

The way that a breakaway system for electric brakes works is when that pin is pulled it completes the circuit between the breakaway battery and the brakes. They have to stay on full for at least 15 minutes to be legal. But there is nothing stopping the brakes from staying on after that 15 minutes is up.

Usually breakaway batteries are 5 amp hour rated. For 10 and 12 inch brakes each magnet draws between 3.2 and 4 amps. So if you have 4 brake assemblies that would be 12.8 to 16 amps. At that much draw they would deplete a standard 5 amp our battery in 18.6 to 23.4 minutes.

But if the breakaway system is connected to the regular trailer battery or batteries then there will be a higher amp hour rating and the brakes can stay on longer. Or, if you are plugged into shore power which has a feature that charges the trailer batteries then they would not lose charge that fast.

It sounds like one of the above scenarios is what is going on with your trailer. I recommend installing a dedicated breakaway battery so that you are in that 18.6 to 23.4 minute threshold (assuming you have four 10 or 12 inch brake assemblies). Breakaway kit # 20400 is a great option. You will also get a new switch with it and it has a built in charger so the breakaway battery will charge while you tow. You will want to make sure this system is not wired into the existing battery system. It needs to stay independent.

expert reply by: Michael H