I bought this charger because I'd harvested some 18650 cells from a pair of old laptop batteries and wanted an inexpensive means of charging them individually. I also have a motley collection of NiMH AA cells that I use in multimeters and other test gear. I don't like alkaline cells for tools because they have a tendency to leak after they discharge, and I''m sick of cleaning corrosion off the battery terminals on my less frequently-used equipment.
This charger topped up every 18650 and rechargeable AA that I plugged into it. I have 4 AA cells in it now that have been in it for a week. No danger of overcharging and I know I'll have fresh batteries when I need them. It even charges some garbage "recycled" AA NiMH batteries I bought in bulk lots that my other battery charger won't even recognize. It would be perfect if it had a spot to charge a 9V battery, but it does everything else so well that I really can't complain.