Motor choice and battery for uphill riding
I'm building a heavy duty electric bike to help me pull stuff upp a long hill. No need for it to go very fast ~15km/h is fine, but it needs to be strong so that it can work for a long time with load and uphill. Weight of the total vehicle + rider is ~130 kg and the slope angle is max ~20%. Would be great if the engine could work continiouselly for at least 2-3 hours.
Any idea if is possible? Can I use a "standards" e-bike engine? What power do I need (500W or more?). Which batteries would be suitable? Do I need to "gear down" a standard e-bike engine to fit this purpose? Any idea of typical weight of a motor + battery pack for this application?
Thank you very much in advance for input.