To function: The adapter can be used universally for all smartphones and other USB devices. The data lines in the USB connector pin 2 (white cable D) u. Pin3 (cable color green + D) to be bridged through the adapter that is shorted. Thus, the smartphone loads with higher charging current (about 850mA or more) in AC mode. (Smartphone "thinks" it would be connected to 220 volt). If you connect pin 2 + Pin3 not short, it would (max 500 mA) load only in USB mode. The guarantee only if all functions of the smartphone are used, the more the battery anyway Loading, provided one uses a high power car charger such as the Kensington PowerBolt Duo: Dual USB car charger for iPhone, iPad, iPod and other USB devices, 2.1A 1x, 1x 1A