Homemade Electric Kart using a 2,9 kW Forklift Motor
Specification
- Top-Speed: 35 km/h forwards and backwards
- Weight: 240 kg
- Turning radius: 0,5 m
- Brake: Rear only, wodden block
- Suspension: Rear swing arm only
Features:
- Switch for selecting driving direction
- Switchable differential-lock
- Front light
- Trailer hitch
Components
Motor
- Type: Serial wound DC motor
- Previous application: Forklift
- Power: 2,9 kW
- Voltage: 24 V
- Current:
- Rated: 156 A
- Measured: 25 - 500 A
- Rotational speed: 1780 rpm
Early setup with temporary wiring
Drivetrain
- Custom adapter from motor (helical cut spur gear) to sprocket for chain
- Chain: 06B-1(3/8’ x 7/32’)
- Sprockets:
- motor: Z13
- axle: Z40
Tires
- from car trailer
- 4.80/4.00-8
- Tubeless
- diameter 400 mm
Control
- Custom PCB with ATMEGA 8 microcontroller
- Control method: 124 Hz PWM
- 600 A 1000 V IGBT (FUJI 1MBI600PX-140-01)
- Audi gas pedal
- Custom knife switch for direction selection
Drivetrain maintenance
Direction selector, IGBT and Diode
Battery
- Voltage: 24 V (2x 12 V in series)
- Capacity: 2,4 kWh (2x 12 V 100 Ah)
- Type: Deep cycle AGM
Experience with battery types:
Over the years different kinds of batteries were tested:
- VRLA Starter battery
- Positive: Very high discharge current
-> Noticably higher motor torque - Negative: Fast loss of capacity when discharged too much and often
(bad deep cycle capability)
- Positive: Very high discharge current
- Lead GEL battery
- Positive: Suitable for very deep cycle applications (high actual usable capacity, with comparably less capacity loss)
- Negative: Low discharge current
-> Significantly reduced torque in combination with this very current demanding motor (was almost unusable)
- AGM deep cycle battery
- Slightly less discharge current than the Starter battery, but higher cycle stability
- Best option so far
- Lithium-Ion battery?
As Experienced in the E-Bike project, Li-Ion would be the best type in terms of weight to capacity ratio and cycle stability. But building a lithium-ion battery in the appropriate size for this project would simply be too expensive.
Different battery types used: VRLA, GEL, AGM deep cycle
Battery change
Videos
YouTube video
Tests
First test drive
2015.04.16
First motor test
2015.03.01
Suspension test
2015.12.10
Fails
Battery pole melts
2019.05.27
Short circuit
2015.12.10
Build process
Axle thread cutting
2018.07.06
Casting battery pole
2019.06.01