1 Advanced drive train components for electric vehicles Understanding e-Bike Propulsion Systems: The Controller Robert Lankin September 23, 2010

Agenda What’s a controller? Servicing a controller Selling a controller 2

What’s a controller? Electronic module Between battery and motor Regulates motor speed Prevents excessive currents and overheating 3

Controller complexity Simplest: on/off switch for DC motor Variable speed DC motor + twist throttle Brushless motor with hall sensors Brushless motor without hall sensors Pedelec torque sensor Smart communication with battery Smart communication with display Built in diagnostics and programming 4 Increasing Complexity

Simple DC System 5 M1

More Complex System 6

7 M1 Controller Throttle Brake Switch BMS Display Bottom Bracket Sensor More Features More Complex to Troubleshoot

Agenda What’s a controller? Servicing a controller Selling a controller 8

Servicing a controller 1.e-bike doesn’t go at all 2.e-bike doesn’t go as far or fast as it used to 3.e-bike acts or sounds strange 9

Servicing a controller 1.e-bike doesn’t go at all –Check power to controller (battery, fuse, switch, wiring) –Burnt smell? –Check controller LED for error codes (read manual!) –Check throttle and brake signals at controller –Check motor hall signals (wet?) –Spin hub motor backwards, check for AC voltages – zero voltage means failed wiring somewhere 2.e-bike doesn’t go as far or fast as it used to 3.e-bike acts or sounds strange 10

Servicing a controller 1.e-bike doesn’t go at all 2.e-bike doesn’t go as far or fast as it used to –Weak battery or defective charger –Low tire pressure –Mechanical friction (bearings, alignment, brakes) –Intermittent operation may be overheating due to loads, friction, or defective temperature sensor 3.e-bike acts or sounds strange 11

Servicing a controller 1.e-bike doesn’t go at all 2.e-bike doesn’t go as far or fast as it used to 3.e-bike acts or sounds strange –Pulsations or dead zones may be bad hall sensor, wet hall sensor, or hall sensor wiring problem –Erratic forward motion may be faulty or lose connectors –Conversion kits may have mechanical fatigue in axle, spokes, rear sprocket 12

Agenda What’s a controller? Servicing a controller Selling a controller 13

Selling a controller Power rating (250W vs. 500W vs. 750W) –Hill climbing, acceleration, head wind, loads –Compare bikes, compare routes Voltage rating (24V vs. 36V vs. 48V) –Higher voltage typically with higher power Throttle vs. pedelec –Inexperienced vs. experienced riders Feel: smooth and intuitive vs. hesitations –Ride and compare different systems 14

Selling a controller Features –Sensorless – fewer service issues, but may need a running start –Regenerative braking – improved range, perhaps improved braking feel –Reliability, durability, weather resistance –Integrated diagnostics 15

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