Comments on the Walmart Bike. I weigh about 225 pounds:

1) If you put the battery in wrong the first time, the fuse will blow.
2) The motor is an ASSIST motor. It does not have the power to run the bike by itself.
3) Am not sure if it will help enough going up very steep hills. Will be testing.
4) The motor control has two SAFETY use modes for the motor. a) Power assist after you are moving. b) Power assist after you are pedaling. There is a twist DEADMAN throttle, which only continues working if you twist it.
5) Bike has an extra slot for a second battery pack. You switch between PACK-A or PACK-B depending on which has energy.