At first I was happy with dem.Akku, he has up to 8 times charged the Iphone. But after about 20 charge cycles he began to spin and fell several times completely. One could no longer make until he became the loading connected him. That has indeed now set back and he is working again, but he has now lost more than 50% of capacity. I've gotten a new phone (Xperia Z1) and this has a 3000 ma. Battery, the can powerbank charge just so twice (the second time only to 80 percent). This is a battery as quickly as weak, can actually lie on the manufacturer, because a good battery should lose at least about 20% percent after several hundred charging cycles