Question: how many volts is 6 aa batteries?
Answer: Looking at Duracell alkaline battery specs, 6 AA cells will last roughly 15 hours at 100 ma drain to 7.2 volts. One 9V battery will last 2.5 hours at 100 mA drain to 7.2 volts. 7.2 volts is about the cutoff for battery use per cell for most electronics (1.2 volts per cell).