The EcoReco M5 is a 'last mile' electric scooter. It weighs ~36lbs and costs $1200. Where does the weight and cost come from?
Our observations (teardown gallery below)
- Battery (blue) fills most of the space in the main chassis.
- There are a standard set of battery discharge and charge connectors, throttle and display, power.
- The motor includes Hall-effect sensors
- There are jumpers to limit speed to 7.5mph or 12.5mph and to disable the 'safe-start' feature.
- The hub, motor and brake are combined in a single unit
- Electronic speed control is sealed against weather and has a row of IGBT transistors inside the heat-sink.
- Battery 3kg (5cm x 10cm x 39cm)
- Rear motor/wheel 3.1kg
- Back cover 220g
- Top plate 85g
- Bottom chassis, front wheel, handlebars: 10kg (22lbs)
- Battery: 256 watt-hour LiFePO4 battery weighs ~3kg; $124 retail.
- Frame: un-powered kick-scooter weighs 4.5kg (9.9lbs); $249 retail.
- Motor: An e-bike conversion kit (complete with controller and brakes) -ships- at 6.6kg (14.6lbs); $280 retail.
- The frame, handlebars and front wheel are overbuilt and could be reduced in weight by half (from 10kg to 5kg or so) so that the entire package could weigh 10-11kg (22-25lbs) even using the same battery and motor.
- It may be possible to shave another kilogram off through different choice of battery/packaging or by limiting range/acceleration.
- Also may be able to reduce some weight in motor but this would require close work with motor manufacturer.
- Electronics don't take up much space or appear to need a lot of cooling, so are not a limiting factor for higher power.
- Speed control could be improved by adding a 'freewheel' mode - this should be not difficult given that the motor has position/velocity feedback from the Hall effect sensors.
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