Linsheng , Portable Car Air Pump: 5 Steps
linsheng here guides the correct use of car air pump, for your reference:

  
Instructions

  
1. Insert the rubber valve top valve directly into the tire valve. When you hear the tire venting sound, it indicates that the air has flowed and tighten the charging knob.

  
2, remove the power clip, red clamp the battery positive, black clip battery negative, or directly into the cigarette lighter power;

  
3, open the motor, you can start to inflate;

  
4. When inflating, the meter pointer starts to rise with the air pressure, and when the large pointer reaches the appropriate tire pressure of the car (the general tire pressure is 30-40 PSI), the inflator switch is turned off, and the plug and the nozzle are taken out.

  
5. Please use the professional ball needle and mouthpiece equipped with this machine to connect with the air nozzle to inflate the ball and other gas-demanding equipment.

  
https://www.linsheng.com