Power Assist to behave like a turbo-charger or cruise control?

Mike leroy

Active Member
In my case, I need power assist to behave like a turbo-charger, not cruise control. I would like to use power assist to function like a transmission, rather than energy conservation. Match torque to RPM to optimize power. I was told transmission-like functionality is not possible.

My option is to turn pedal assist off (PAL 0). I will use the throttle as a turbo charger in the few, short, extremely steep sections.

To my way of thinking, throttles are better than pedal-only systems. At the very least, a throttle enables you to optimize the tradeoff between speed and battery consumption to find the best balance.
  • How to configure PALs to correspond to hill steepness optimize the entire power system, rather than just battery consumption?
  • Is it wasteful to use power assist in a high gear?

The BBS02 allows nine (firmware update) levels of assist to be configured. Each assist level specifies the ratio of leg/motor power, not wattage. Wattage is not a parameter because the controller software factors cadence into the algorithm.

Both torque and gear shift sensors will be available for BBS02 or BBS03 from lectriccycles.com in the near future. Only a controller replacement is necessary. Additional sensors improve gear shifting, but make power level configuration even less possible.

Mashing gears will become less of a risk with these future improvements.

My main route is 2700m or 1.7 miles and 600 foot elevation change. My trip is entirely up or down a canyon, not rolling hills:
  1. 10% grade for 400m
  2. 02% grade for 400m - power unnecessary.
  3. 18% grade for 250m
  4. 10% grade for 200m
  5. 05% grade for 500m
  6. 02% grade for 1000m - power unnecessary.
My guess is the PAS Cadence algorithm is expressed conceptually, below. The throttle overrides the PAS algorithm.

Watts = (CadenceRPM x MotorPAL% x MotorMaxWatts) + leg power;
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