I have a leed's power bank 7120-49 capacity 3.7V/2200mAh, input DC 5V/550mA. It doesn't seem to charge I have had it charging 24hrs and nothing. The output is 5V/100mA. If anyone can give me any ideas. When I first got it it did have some charge and it did seem to charge my s4 at least for a short time. But now it doesn't, I have used same USB cable.