Emergency Brakes

I made that mistake years ago on a pull trailer and everything worked perfect,was leaving for vacation after the grave yard shift and left the pin out and came home and all was good. I think as long as the magnets are in contact with metal they will not get fried from the prolonged energization. The brakes themselves do nothing till the disk forces the energized magnetic puck to pull the pads open
I think you are good to go amy have taken some long term life out of the batteries though.