Choosing the power rating of a Bafang motor for legal operation under EN15194?


Staff member
Local time
1:59 PM
Jun 16, 2018
The Electronically Power Assisted Cycles (EPAC) Standard of EN15194, states that the maximum rated power of an ebike is 250W.

Power at the driving wheel (or wheels) of an ebike will be less than the motor’s rated output. This is due to transmission losses, wheel-spoke distortion, tyres ect. If the e-bike’s maximum output power is 250Watts, the motor’s maximum output power should be about 320Watts.

The motor’s maximum output power is also related to the design of the ebike. Transmission losses should be reduced as much as possible so that the battery resources are used efficiently.

Under the following conditions the motor power draw is between 150Watts and 250Watts:

  • Speed of 25 km/h
  • Flat road
  • 75 kg Rider Weight
  • Wind speed Force 3 or less, – as determined by the rider’s pedalling power and the controller’s setting. When going uphill or with an increased weight or stronger headwind, the motor draws more power.