I can say one thing the Cateyes only last 5 to 10 hours using alkaline, after that the power drops off. Yes you can get up to 100 hours of lesser and lesser light output from them but they suffer in the brightness category. When I notice this the first few times, I started swapping them out and saving them for future use in a couple of headlamps I own. With the lithium batteries I get up to 40 to 60 hours of good output. Then for my own peace of mind, I swap them out for new lithium batteries.