The voltage on the industry standard 9-volt battery is, obviously, 9 volts. Energizer's 9-volt battery's milliamp hours equal 610, or 5.49 watt-hours. Thus, the 9-volt battery has a greater capacity than the AA, which means that it is likely a 9-volt Energizer battery will outlast a AA battery.
Herein, how many milliamps are in a 9 volt battery?
A circuit that draws 10 ma powered by a 9 volt rectangular battery will operate about 50 hours: 500 mAh /10 mA = 50 hours The cell voltage of alkaline cells steadily drops with usage from 1.54 volts to about 1 volt when discharged. The voltage is near 1.25 volts at the 50% discharge point.
How many hours do you get out of a 9 volt battery?
So, if your 9V battery is rated at 600mAh and your device draws at a maximum of 25mA, then your battery would last 24hours in theory.