Laser life on a miter saw

This is a question to get an idea if it’s worth replacing batteries again or if something is wrong.

I have one of those laser line indicators on my Bosch 12” sliding compound miter saw. It mounts on the armature of the saw right next to the blade. I kind of like it. It is a nice feature. The unit came with three button batteries installed and an extra set. I went through the installed batteries in about a month and installed the second set. They lasted a little bit longer. It’s not like the saw was spinning for hours to make them light up. I’m wondering if this is typical, if it is I probably won’t replace the batteries again, or if maybe I just got a set of batteries that were sitting a long time in the box in some warehouse until I purchased the saw and they might have been partially dead to begin with.

Does anyone have this saw or a similar setup and how long do your batteries last?

Thanks.

-- The smell of wood, coffee in the cup, the wife let's me do my thing, the lake is peaceful. http://web.me.com/deceiver6/Deceiver/Craftsman_on_the_lake/Craftsman_on_the_lake.html