USB car charger is an universal charger used in car for charging 5V devices like smart phones, ipad , GPS and so on. USB car charger is a adapter which can turn 12V and 24V into DC 5V. Normally the output of usb car charger is 5V 500mA, 5V 1A and 5V 2A. Different output for charging different devices in a fast way.
Below is the basic structure of usb car charger:
Insert the positive pole of usb car charger into the cigarette lighter hole. The USB ports are towards outside
Pls note that there are two spring strips around cigarette lighter hole. pls make sure negative poles of usb car chargers not inserting into the hole just right above of spring strips.
When the usb car charger is connected rightly, the LED indication would be on.
Once connected rightly, you can charge your smart phones by USB cable.