Depends on how you built your coils and how far down you vape your volts. The amount and thickness of wire used will effect the battery drain. Single wire, twisted dual wire, twisted triple twisted ribbon, will all affect the drain on the battery. Anywhere from 2-3 hours total vape time is good.
I asked mister Owl, and he said it takes three licks to get to the center of a tootsie roll pop.