The weather has a lot to do with that. Somewhere around 2 months I guess. That's about 10,000 pics into it. The m-80 can go for a month longer alot of times and the m-880 can last even longer. My cameras take 15,000-20,000 pics a year, probably more. If your cameras won't be taking a high volume of pics like that then you shouldnt even worry about it.