Tendak Smart Battery 8400mAh Portable Charger External Battery Pack Backup Power Bank for Iphone & Smartphone and Tablets It has intelligent protect function and can recognise your cellphone and support a corresponding current. Charging the cellphone with the lagest current when in quick charging mode, smart change to 0.1A-0.3A when the cellphone is near fully charged, protect your cellphone and the power bank. This is really different with the ordinary power bank. For example, iphone 6 receives a 0.6A current after 90% of charging, but ordinary power bank will always support 1.0A Light weight with 8400mAh capacity for Charging iphone 6 about 3 times. With CE, FCC, RoHS certificate 2.1A output, can charge two devices at the same time, but the current must be lower than 2.3A. It has a overcharge protect function that will shut off the current when over 2.3A Only need about 4.5 hours to be fully charged power bank. 1.7A-2.0A input current when in quick charging mode (need 2.1A adapter, not included). Will be reduced to 0.1-0.5A after 90% of charging. Ordinary power bank with 1.0A input will take over 10 hours to be fully charged LED display shows the battery level and current so that you can see the true power and knows when to charge it. Ordinary power bank with a power button on the obverse, easy to be pressed and powered on when put it in the bag while our power bank features the power button on the side