Bought six months ago, this external battery is reliable. Its max amperage slightly lower than 10.4A / h announced by PNY, but all batteries are affected by this phenomenon, the measurement being made probably empty out onboard electronics.
I still managed to make 3 full loads of a smartphone with a battery of 3000 mA / h. By cons, it failed to load 2 times a shelf with a battery of 5000mA / h. The second load was 90% when the battery was empty.
