1. Many cars have their own interfaces, and some have more than one interface, but some usb interfaces are not for charging mobile phones, but are configured for audio data transmission, because most vehicles on the car have very small interface currents. 5V/ 0.5A, if you use the USB port on the car to give the mobile phone, if the current does not meet the standard, the device will be damaged. Therefore, it is recommended that the car owner purchase a car charger separately.
2. The more usb interfaces, the slower the charging speed: the current depends on the voltage and does not depend on several usb interfaces, because the current is intelligently identified and does not interfere with each other. Some manufacturers design multiple usb interfaces, mainly to meet the requirements at the same time Charge multiple mobile phones in the car.
3. Be sure to unplug the usb car charger after the flame is turned off: Generally speaking, the car will automatically cut off the power when it is turned off. Then, should you unplug the usb car charger when the car is turned off? It is recommended to unplug it, although it will be unplugged. A certain amount of battery power loss is negligible, but it is also very important for the maintenance of electronic products. Proper maintenance can extend the life.