1200mAh sounds first not bad, at second glance, things look but quite different. I can believe that can give the USB charger 1200mAh out, but he does not as a rule. This is mostly due to the connected cable. Assuming that is a standard USB cable then detect the connected mobile phone charger as a USB port and then contracts, according to the USB specifications, only 500mAh. For the full charging current, the phone would only pull when it "thinks" it depends by power supply to the power outlet. This charging mode detects the mobile phone but only if the two data lines are bridged in the cable, they are not so in most cables. So if you utes the full charging current will have to buy either a suitable cable or bridge the two lines right in the car charger. I have indeed done, open housing and bridged the two middle contacts of the USB socket on the board by soldering and already shows me my phone to which it takes full charge current (AC).
