Speed is no witchcraft, thanks to the USB-C port (PD/QC capacity). In PD operation, the charger performs to its full potential. Out: 8.4 V 1500 mA (1 battery) 1000 mA (2 batteries) IN: PD 9 V = 2 A Out: 8.4 V 1000 mA (1 battery) 600 mA (2 batteries) IN: 5 V = 2.4 A Supply - via USB PD power supply (USB-C to USB-C cable included in pack) or any USB source: USB power supply, laptop, PC, USB car adapter, power bank, solar panel, etc.