@thomasfuchs I have 4 of these I use while traveling. They don't have the capacity of a quality NIMH cell, but because they're voltage regulated, they basically keep putting out a pretty consistent voltage until they're nearly dead, instead of starting at sub alkaline volts and sagging off like NIMH batteries. I find them very convenient, because I don't have to carry along another charger in my gadget bag. These things are great imo. The ones I have charge via micro-usb, but same concept.