The desired performance targets are:
If a 100 lbs vehicle with a 700 lbs load does not have a multiple speed transmission and the motor will directly power the drive wheels via a chain then our Motor Power Calculator calculates that a motor around 4000 Watts would be needed to be able to climb a 10% grade with a top speed gear ratio that provides 15 MPH top speed.
However since the target speed on flat ground and minimum speed while traveling up a 10% incline are so far apart a 1000 Watt motor could be used provided that there was a multiple speed transmission in the driveline which would provide a 1 to 4 gear reduction for climbing 10% inclines and a 1 to 1 gear ratio for traveling on flat ground.
We do not currently carry motors in the 4000 watts range or multiple speed transmissions so we would not be able to put together a kit for this type of project at this point in time. We do have many parts which could be used for the project though, but unfortunate not all of them.
We have a Ride Time Calculator which can be used to estimate ride times for electric powered vehicles and carts.
For anyone interested in our kits we have hundreds of Electric Power Kits available for projects ranging from electric scooters and bikes to beach wagons and industrial carts.