For an AA Alkaline battery, the Eveready data book lists the
following loads vs. hours, to a cutoff voltage of 1.0 volt:

1500 ohms = 1850 hours
300 ohms = 340 hours
150 ohms = 160 hours
75 ohms = 82 hours
50 ohms = 54 hours
30 ohms = 32 hours
10 ohms = 7.8 hours
4 ohms = 2.3 hours

Hope someone will find this to be helpful.