I am running a single, LiFe 3000mah, in my Pitts with a Tech-Aero ign cut off. So far I can fly two days, 3 flights each, before recharging. About 1-1/2 hour air time, and not a single glitch to boot.
It is powered by a 55cc twin.
I am so happy with the set-up I am switching my Ultimate over to one battery. It needs replacements.