I've been buying and using Walmart/Duracell batteries because nothing else but Lithium is said to last very long. I'm only getting about 1 to a month and a half with them at best requiring constantly inspecting and replacing batteries through out the season for non-cell cameras. A pain except that my cell cameras that can notify me when batteries are getting low. Next year I'm going to shell out for lithium batteries. Any advice? I would use solar charged external batteries but most of my cameras are in the woods and I don't think they would receive enough sunlight to keep them charged. Are you using alkaline, lithium, or solar for power? Observations appreciated.