The break away should be wired to your 12 volt battery, or to the positive wire in the 7 pin plug between the truck and the trailer battery. The systems that have the seperate smaller battery on the tongue frame, are for smaller, or older units, that (usually) don't have a 12 volt battery.
Follow the wires from the break away switch, and one will go to a positive power source and the other will connect to the blue wire going to the traile brake circuit. It doesn't matter which wire goes where, since they're interchangeable. When the pin is pulled, it just completes a simple 12 volt circuit.
If you're going to "regret it in the morning", sleep until noon.
2012 Jay Flight 19RD
2016 Ford F150 XLT 2X4 SC 3.5L Eco Max Tow
2010 Tundra TRD DBL Cab (Traded)
2 new fluffy Corgis, Bayley and Stanley