Think of all of us that have brake systems that don't have that problem. I doubt they could sell many brake systems if we all had dead batteries at the end of a travel day.
I would take a hard look at why your Jeep can't hold a charge. You may have a draw you don't know of, a dead cell in the battery, running lights that stay on because a fuse isn't pulled, etc...
I only had a dead battery once and that was because when I had the key on Acc. the fan could run, I didn't notice it and that's what drew down the battery.
Having a jumper unit is a good idea regardless, but should not be needed to run your system.