You can easily charge the battery of the Zehus all-in-one hub motor by connecting the e-bike to a normal power outlet with the supplied charger adapter. Take off the screw cap carefully that's mounted on the axis of the rear wheel and then just connect the adapter to the battery. A full charge of an empty battery takes around 3 hours. Don't forget to return the screw cap after charging your e-bike. For safety reasons it is important to charge the battery indoors. Outdoor charged should only be considered on dry days and with great care.