I run my black box and my Ultra 122 Livescope system 8 hours plus off of a single 35AH AGM battery with no issues. I think the lowest I've seen the voltage drop to is 11.9. It is really a pretty small battery. It sits right beside my black box in a small compartment in the bow of my Lund. I would definitely recommend connecting both the black box and the unit to the same power source and not the cranking battery. I've been running my Livescope system this way for the last year without any issuses.