Pro Shot L3 and L5 lasers run on 2 D batteries, while the L4, L4+, L1-AS, and L1-AS Magnum run on 4 C cells. Disposable alkaline batteries or rechargeable NiMH batteries can be used. We recommend the NiMH rechargeable batteries. They provide almost as much run time as alkaline batteries, (more than 40 hours in all our lasers), and can be charged up to 500 times under optimal conditions. They provide hundreds of dollars of savings in battery costs over the life of the laser. Furthermore, NiMH batteries are less toxic to the environment, and put less strain on our landfills than alkaline or NiCd batteries.