I've had a Nikon 400 laser rangefinder for a number of years now, probably 10 to 12, something like that. We use it infrequently for measuring distance - how far did that Frisbee throw or golf shot go, how far away is that building, etc. It's very useful for sports, none of us hunt any more.

Originally a battery lasted at least couple of years. CR2s are about $10 each, so that wasn't bad.

Now it's a couple of weeks. They seem to discharge when not being used. Is that characteristic of an older electronic device, that it may develop some small leakage current over time. I can leave the battery out until I need it, but I'm curious.