there are 4.2 A distributed promised to 2 USB ports with 2.1 A In the bedinungs guidance of my unit 2A are required. I do not care Welsh port use, my device is loaded only in the off state and that does not even besonderst much in 2H 20% off device. With my car power adapter with 24V truck. If the device is fully charged in betrib after 3h.