Etek motor sub-frame36V 30 Ah lithium sub-packDual 36V/8A chargers
OwnerMalcolm Berry
LocationNewcastle upon Tyne, England United Kingdom map
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Vehicle2000 Cagiva Planet 125cc
Alloy frame, original weight around 130 kg
MotorBriggs and Stratton Etek Permanent Magnet DC
DrivetrainDirect chain drive: 13t front sprocket, 60t rear sprocket,
giving ratio of around 4.6 to 1.
ControllerAlltrax AXE 7245
A reliable waterproof and programmable controller that
operates up to 90 volts and 450 amps. My only criticism is
that the throttle response is a little too twitchy, even with
careful adjustment of ramps and throttle curve.
Batteries72 LifeBATT 10 Ah, 3.20 Volt, Lithium Iron Phosphate
Twice the range of the original lead acid pack, but around 15
kg lighter. Some of that gain is lost due to the added
protection needed by cells.
System Voltage72 Volts
Charger Lifebatt 8A 36V
One charger for each 36V sub-pack. These are isolated, so
can be connected in series. Auto-cut off at 43.8V = 3.7V per
cell. Fechter/Goodrum battery management system
( makes sure no cell is overcharged or
DC/DC Converter 72V marine DC converter
InstrumentationDrain Brain, high amp version with speedometer.
Top Speed70 MPH (112 KPH)
Increasing the pack voltage from 60 to 72V and reducing the
gear ratio from 5.5 to 4.6 has made a big change in
performance. Lots more torque between 40 and 50 mph.
AccelerationGood. Able to stay in front of most city traffic.
Range30 Miles (48 Kilometers)
30 is the maximum using modest acceleration and pulse and
coast technique.
Watt Hours/Mile85 Wh/Mile
Mostly city use, with short stretches of urban motorway.
EV Miles
Current:600 Miles (965 Kilometers)
    As of 9/26/2010
Seating Capacity2 adults
Curb Weight290 Pounds (131 Kilograms)
About the same as the original ICE bike.
Tires17 inch. 150/60 rear, 120/70 front.
Conversion TimeAbout two months of weekends and evenings actually doing
stuff, and about 18 months scratching my head.
Conversion CostStopped counting a long time ago.
Many thanks to the good people at Endless Sphere forum for their help and inspiration,
and to all the other contributors here!

code by jerry