The F-Stop for cameras is the aperture that allows light in to the lens. There is a range of f-stops that go from f-1.4 all the way to f-16. The smaller the number the larger the opening of the aperture... the larger the opening the more light... if you can manually control the F-stop then you can use more light in situations where you would normally use a flash... this would save batter life.
Hey, thanks for your response, davenmidtown. I don't think I can control the F-stop...it seems automatic, so I'll have to read my instruction book. I don't use the flash a lot, but I do perform editing on-camera a lot and I'm sure that is some of the down battery use. Appreciate your help! Someone told me before to freeze batteries to make them last longer, but I don't accept that. ?