Paul Nilssen's Ransomes Electric Mower

Owner	Paul Nilssen
Owner's Other EV	Electric Mower Mark ll
Location	Penguin, Tasmania Australia ^map
Email
Vehicle	Ransomes Self propelled lawnmower
Motor	Lucas Separately Excited DC Originally a car starter motor. I rewound the field and now have a two speed motor.
Drivetrain	Seperately excited DC and chain reduction
Controller	Switch and relay for two speeds and switch and solenoid for armature current
Batteries	1, 12.00 Volt, Lead-Acid, Flooded Second hand from a diesel Hilux
System Voltage	12 Volts
Charger	Home brew
DC/DC Converter	None
Top Speed	Low speed is too fast and fast is dangerous.
Acceleration	Woah!
Range	Good for a very small flat lawn
Tires	Steel drum drive
Conversion Time	A couple of months after work and weekends
Conversion Cost	Mower (rescued from the tip) $0 Motor $20 Bits and pieces from my shed and 'donated' from work. $30 Total = Not much.
The original series DC motor configuration was way too fast. I cobbled together a 100A PWM controller, but this just slowed the acceleration not top speed. This led me to rewinding the field coils. Now the motor runs only a little too fast on slow speed (with field current) and way too fast on high speed (without field current). PWM controller is no longer used. The starting circuit includes a switch to control an automotive starter-motor solenoid for armature current. On or off. With a bit of sideways thought and a few skills, a scrapheap mower has been turned into a (nearly) useful electric device. Minimal cost and heaps of fun!