E-bikes vary brand to brand and model to model. In general, they can be propelled down the street solely on battery power for a few miles, but the more common use of the bikes is for the biker to pedal, with the battery providing a boost. The Rad Power Bike, as with models from companies like A2B and GenZe, The e-bikes use small electric motors that can power the two-wheelers up to 20 mph and can run for 25-40 miles on a single charge.