If the batteries are that bad, then maybe I should be filing a claim against Mountain Electronics. They're the ones that sold me them. But I guess I should make sure they're the problem somehow. We have a Batteries Plus store here. I imagine they'd probably test them for me just so I can tell right away if they're the problem. Or yes, I could buy a tester. I thought it was bad enough to have to purchase special batteries and a special charger just because I wanted a laser, and now it looks like I need a special battery tester as well.
EDIT: I forgot to mention that the tester I have has settings for 3V 1ma, 6V, and so forth. When I put it on 6V, both batteries made the needle go up about half way. Since these are 3.7v, that sounds about right, doesn't it?