Because of battery capacity limitations. Unlimited. Can't work for a long time, the air pressure is not enough. Some people connect it directly to the cigarette lighter. The power can be higher.
The use of vehicle air pump:
1. Obtain power
The vehicle air pump can be powered in two ways, namely through the 12V cigarette lighter interface and through the battery.
2. Connect the air nozzle
Unscrew the tire nozzle cover and connect the pump's inflation tube to it (in general, the connection port of the inflation tube is connected by threaded rotation).
3. Set the inflation pressure
After the pump is successfully powered and connected to the air nozzle, the air pressure can be set on the setup panel. The gas pressure standard labeling is generally affixed to the B-pillar area of the vehicle or the inside of the fuel tank cap.
Car air pump I think is wired easy to start the car power supply power can be normally input to the air pump