Bafang and Tongsheng motor and battery kits from $600 - $1500. I will inspect your bike for the best motor setup. You purchase the motor kit from Amazon, Ebay or AliExpress. 500w to 1000w Mid Motor Conversion Kit with Large Capacity Lithium Battery The most powerful electric motors on the market with the longest lasting battery. Turn your old or new bike into a pedal assisted or full throttle with a choice of motors, frame or rack battery mounts. Install and tune your motor kit for $150.