Why can't the USB interface of car GPS charge Apple mobile phone with data cable?

The data cable for USB interface of car GPS can't charge Apple mobile phone because the USB interface current of car GPS is very small.

generally, the USB interface of vehicle-mounted GPS is used for importing data, just to keep the power supply of the USB flash drive or transmission equipment, which is not more than 5mA. Vehicle GPS Shenzhen GPS is called vehicle GPS when it is made into a GPS positioning terminal by hardware and software for vehicle positioning, but positioning alone is not enough, and this positioning information should be transmitted to the alarm center or the vehicle GPS holder. We call it a third party.

therefore, the GPS positioning system also includes GSM network communication (mobile phone communication), through which the satellite positioning information is sent to the third party by SMS. The short message is interpreted by microcomputer, and the vehicle position is displayed on the electronic map. In this way, the vehicle-mounted GPS positioning is realized.

Universal Serial Bus (abbreviation: USB) is a serial bus standard for connecting computer systems with external devices, and it is also a technical specification for input and output interfaces. It is widely used in information communication products such as personal computers and mobile devices, and extended to photographic equipment, digital TV (set-top box), game machines and other related fields. The latest generation is USB 3.1, the transmission speed is 1Gbit/s, the three-stage voltage is 5V/12V/2V, and the maximum power supply is 1W W. The new Type C plug-in is no longer positive or negative.