It may depend on which brake assist system that you use. I have a Blue Ox Patriot 2012 Brake Assist Unit. I had that happen to me when driving back from VA Beach to Manassas, VA. Just north of Richmond I got an error code 04 on my remote unit. I pulled off at the next exit because I was afraid that the toad would just brake and seize. It didn't. But the battery was dead and I had to jump start it. I just had my girl friend drive the toad the rest of the way. I later read in my manual that the Blue Ox Patriot stops working when power runs out except for the break away cable, if it is attached.