Shimano Steps Battery Charger mooth and Silent Riding with INTELLIGENT POWER : Discover high-level E-bike performance. Shimano STEPS lifts E-bike enjoyment to the next level by optimally balancing range, lightweight performance, and low noise with battery power to spare. SENSOR TECHNOLOGY : Shimano STEPS incorporates sensors that pick up information about torque, speed, cadence, and crank position so that the system can provide smooth and optimally matched pedaling force. SYMPHOMATIC: Shimano STEPS computer-assisted shifting system provides a more responsive and stable shifting performance. This innovative system monitors rider's motion and determines the optimal timing to momentarily decrease power to the pedal-assist motor. The temporary reduction of chain tension allows the gear movement of drive train to function smoothly and unimpeded. CONVENIENT FUNCTIONS Start Mode: When you come to a stop, shifts down automatically to an appropriate gear for when you're ready to push off again. As E-bike riders tend to use higher gears and sometimes forget to shift down when they stop, this feature can reduce the drain on battery power. It's another Shimano original Di2 technology.