Finally einemal a USB charger, which supplies a Navi PLUS a smartphone with the power corresponding to the required! I've had some USB chargers plugged into my car to drive a Navi PLUS a smartphone at the same time! Only that was not long good! With this USB charger with no hassle! Due to the fact that each of the three existing USB port is interpreted differently (amperage), the use of the port is the best choice for every car!