So I bought this extra battery to charge my iPhone 4S and my iPad 2. I expected to get one maybe two charges out of it. Now granted I did not have a fully drained device when I charged them, but even so my experience with other batteries has been that they don't last but one or two charges.  Another trait of the other batteries is that they don't hold a charge very well, i.e. if you don't use them often then tend to die fast. This battery lasts just fine.