Please Check: Ready to Start Building this Design

BretS

Solar Enthusiast
Is it also fed from your vehicle 7-pin?

That’s the start of issue
Do what works for you if you deem it safe

I prefer separate brake systems when we put high power batteries and SCCs into our RVs
No, power from the 7 pin is useless... it is disconnected. I have a 30A DC-DC charger with 6 AWG wire from the truck. It only allows power to go one direction and charge my bank when driving.
 

shadowsteve

Solar Enthusiast
No, power from the 7 pin is useless... it is disconnected. I have a 30A DC-DC charger with 6 AWG wire from the truck. It only allows power to go one direction and charge my bank when driving.
I'm assuming he's referring to the 7pin feed from the truck brake controller. The +12v feed from the 7pin has no bearing on the brake system and for LFP/solar installs can be disconnected.

The current drawn by an engaged breakaway system is the same regardless of where the power comes from (truck, FLA or LFP) and is only changed by the voltage on the circuit. It's about 3.5A or so per brake drum. It needs to be available for 15min so you need about 2Ah/axle to meet DOT requirements.
 
Top