Open circuit voltage ranges from 1.5 to 1.6 volts. Nominal voltage is 1.5 volts. Operating voltage is dictated by the state-of-discharge and the actual load imposed by the equipment. The voltage profile under discharge is a sloping curve as seen in the following figure. In most instances, 0.8 volts is considered to be the end-voltage.

Typical discharge profile of the DURACELL alkaline MN1500 (“AA” size) cell.