best batteries to use?

i bought a new laser and it eats through alkaline 1.5v batteries. what would be the best batteries to buy? i have considered rechargeable nimhs but they are only 1.2v, would that make a difference?

You can use the nimhs safely for most of the lasers in the market. The worst that could happen is that you had a very reduced lifetime or that it simply didn't work, which would be a very rare case. Just try them, every laser driver is different from each other