the battery on the go

Have in some forums eigntlich only good about Anker Accessories - especially with batteries for charging cell phones read.
In my opinion, a good price / performance / weight ratio. Have taken intentionally know because housing in piano finish. In black you see immediately every scratch, in white, it does not fall quite so on and yes it is a commodity.
Now I have only used the battery twice with my Iphone. So can not make any long-term proposition. Bin so far satisfied.
A side note: I am beginning not the same thought, the full capacity is not available, because otherwise the battery pack itself would be fully discharged and thus would very quickly become unusable.