Laser line generator failure

I have two of these laser line generators, (**broken link removed**) and when I got them they would make a line visible 20ft away. I tested them with a 3V watch battery. Now (~2 months later) I tested them and they are barely visible on a surface 1" away when its dark! What would cause them to be so horrid. I tried using different batteries. Could it be that I mishandled them? Or could the battery sending too much current to the module? I would have thought that the lasers had internal current limiting resistors though. Any help would be greatly appreciated.

Thanks!

ps: If I need to get new lasers, do you know of any good sources to get cheap class II laser line generators?

I feel stupid Even though the two watch batteries were outputing 3V they couldn't provide the amperage. Two seriesed AAs fixed the problem. Again, I can't believe I made that mistake

whoops

Some little lasers and keychain LED flashlights use the internal resistance of small battery cells to limit the current. They wouldn't last long with a battery with a lower internal resistance.