My edc is run off of a stack of lithium disks running one led. I've been using it now for about 2 1/2 months and it seems to be doing fine. It cost me about $4, and when the batts go, I think it will be cheaper actually to replace the whole thing rather than chase down the batteries for it. I am always finding something else that catches my eye, so I guess I am too consumer oriented

I used to have a 4 AAA cell three led light as my edc. I think I replaced the batteries in it once in two years. I just don't use a flashlight that much.