The disclosure provides a charger including a base and a charging circuit. The base includes a coupling portion for detachably coupling with one of multiple supporting stands. Each of the supporting stands has a supporting container with different standards. The coupling portion has a coupling surface. The coupling surface is used for supporting one of the supporting stands. The charging circuit is disposed in the base and the charging circuit has a first electrical connector. The first electrical connector protrudes from the coupling surface. When the coupling portion is coupled with the supporting stand, a portion of the first electrical connector is disposed in the supporting container.