Shaft encoder mountedbatteries and controllermaking the motor mounting frame20Ah rear battery boxesDanfoss controller sitting in positionThe pic-axe based BMSEngine bay
OwnerTuarn Brown
Owner's Other EV1980 Isuzu Gemini
LocationPerth, Western Australia Australia map
Web/Email email image
Vehicle1982 Suzuki Sierra SJ40
4WD soft top
MotorAsea Brown Boveri AN314008 ABB 3-Phase AC
11kW (peak 48kW on controller) 4pole 415V (delta) 80kg
Aluminium frame
300mm wide 500mm long
1450 RPM (50Hz) 22A cos0.81 frame 160M
Locked rotor current 165A @ 415V.
87% efficient @ full load
42mm dia keyed shaft 110mm long
M12 lifting eye.
72.5Nm rated, max 337Nm on controller thus no gearbox required.
Now fitted with Dynapar shaft encoder.
There is nothing special about this motor. It is just a good brand, general purpose, industrial motor. Torque calculations put it at least equal to the ICE and gearbox that it replaced. This motor is a 1980's model from a salvage yard. For new types see ABB WebPage
DrivetrainDirect drive from motor to transfer case.
4WD high / low ratio
Ratios motor to wheels through transfer case..
High 2wd 6.5:1
Low 4wd 10.5:1
4000 RPM (132Hz) gives 82 km/h in high ratio
ControllerDanfoss VLT5042 30kW nominal, 380 to 500V AC line in
DC bus min 470V, max 750V
Extended braking and DC bus sharing options fitted. Weight 41kg.
Max 56kVA. Efficiency 96% at full load.
Controller claims to supply 466% torque on 11kW motor at low revs. This is current limited at lower revs to 97A and voltage limited at higher revs by the DC bus voltage (576VDC) to 408V RMS. Controller often reports 37kW going to the motor and suggests max of 48kW.
Controller can be operated in Speed Open or closed loop mode and also offers Torque open loop and a special torque/speed mode.
Shaft encoder now fitted to the motor so we can run in any mode and use full PID options of controller.
Speed closed loop and torque/speed closed loop are the favourites.
... still learning about the controller settings. But having lots of fun on the way. See
Batteries48 Henda 20Ah SLA, 12.00 Volt, Lead-Acid, AGM
Battery pack is broken into 12 x 48V modules for safety. These are connected in series as +288V, ground ,-288V via relays to the Danfoss controller DC Bus. The relays are operated by the vehicle ignition switch.
Pack capacity @20hr rate is 11.52kWh but at high discharge rate capacity seems to be around 7kWh as expected with SLAs.
Batteries weigh 320kg
NOTE 1st battery pack was 7.2Ah batteries for testing. They had a limited 11km range but otherwise worked fine.
System Voltage576 Volts
Charger 240V single phase
12 x 55V 100W SMPS units. One across each of the 12 x 48V battery modules.
Each battery has the trusty 2 x 6.8V zener diodes and 5ohm resistor for eq.
Charging in 48V modules reduces much of the unbalance in a high voltage string.
Charge time is 8 to 10 hours depending on DOD.
Charging is voltage regulated at 13.6V per battery so is left in float charge. This can be with just one charger if for days or more.
HeaterIt's Perth !
Motor and controller don't get hot so will probably need some electric heating if required.
Airconditioning (reverse cycle) would be my preference.
DC/DC Converter 13.6V 20A
Actually 2 x SMPS one running off +288V to 0V and the other -288V to 0V

Keeps 12V 26Ah SLA charged.
InstrumentationNormal car speedometer and anything you could possibly want to know from the Danfoss. (volts, amps, kW, Hz, torque, etc)
Top Speed51 MPH (82 KPH)
will climb 30 deg gravel slope in 4wd low ratio (wheels spinning, lots of fun).
Acceleration0 to 60 km/h in 6 seconds.
Very satisfactory.
Range30 Miles (48 Kilometers)
Looking for 40km range.
Watt Hours/Mile205 Wh/Mile
From Wh meter before charger. Average over 3 recharges / runs.
Danfoss also logs the kWh output to the motor. This seems to be high, compared to charger input at around 89% (SLAs are not that good !) of recharge power so I need to separate out regen power as regen is obviously contributing a fair bit and regen power is counted twice.
EV Miles
Start:7,276 Miles (11,707 Kilometers)
Current:7,923 Miles (12,748 Kilometers)
Total:647 Miles (1,041 Kilometers)
Seating Capacity2 adults
Curb Weight2,340 Pounds (1,063 Kilograms)
Tiresblack, round, filled with air
standard off road equipment 205/75R15LT
Conversion Time12 months
Conversion CostAUD
motor SH $250
controller SH $2000
wiring/relays/battery eq./fuses sundries $1000
20Ah battery pack $1500
Additional FeaturesVehicle is manual steering and manual brakes, although you don't get to use the brakes much with the very effective regenerative braking.

I should put in a plug (no pun intended !) here for the

Australian Electric Vehicle Association
If you are into EVs in Oz then visit them.
(Yes I am a member)
Project started January 2006 with donor vehicle strip down.

**** Update 14/4/2007 ************************
First road trials last weekend.
Range is small (11km) with the 1st and very modest battery pack and a heavy foot !
We put a peak of 37kW into the motor. It ran cool.

Can't see why you would need a gearbox or clutch. This direct drive system is great. Simple and efficient.

**** Update 20/4/2007 ************************
Just bought 50 x 12V 20Ah Henda SLA's. (320kg)
That will be a more respectable 12kWh.
I'm looking for a 40km range @80% DOD.
The 7.2Ah's are coming out.(4.32 kWh , 127kg)

There is something fantastic about an electric car.
The sounds, the feel, the amps the volts the.. the... lack of petrol !
Each drive is a great experience, like you have only just got your licence !
This will all fade when every second car is electric, but right now it's great.

**** Update 1/5/2007 *************************
Still using the 7.2Ah's (and going strong) while we build battery boxes for the 20Ah units.
Also mounting up an encoder to trial speed closed loop mode of the controller. Will report.

**** Update 12/5/2007 ************************
Shaft encoder works well. Controller now works in full PID closed loop speed mode. This is far more natural from a driver's accelerator pedal point of view. We can now use shorter ramp times on acceleration.

**** Update 24/5/2007 ************************
Still on the 7.2Ah's. Setting up individual battery monitoring and charge equalisation on the 20Ah pack.
... and fitted some new seats !

**** Update 29/5/2007 ************************
New battery boxes with 32 of the 50 x 20Ah SLAs fitted in the back. The other 18 will go under the bonnet.
I talked to a helpful guy at Danfoss and got the torque mode sorted out. It's great. The controller comes up calibrated in Nm torque and the accelerator pedal simply demands Nm !

**** Update 31/5/2007 ************************
ABB Australia came up with the original specs on the (20+ year old) motor, so I have updated these above.
They noted that the new motors in premium range are now 92.2% efficient at full (11kW) load, 92.6% efficient at 75% load and 91.9% efficient at 50% load.

**** Update 17/6/2007 ************************
I was asked why use 600V battery pack. Simple... the most common and least expensive 3 phase controllers are 380 to 500V AC input and an 11kW 4 pole 415V motor is one of the most common in the range and one of the best power to weight. (415V AC x 1.414 = 587V). Remember the idea of this conversion is to use standard low cost industrial parts. Another advantage is the light weight wiring and switches / contactors. I use 6 sq mm wire and have measured total wiring and relay losses at 2V @100A. That's 200W in 60kW = 0.3% ! The batteries are arranged as +300V GND -300V DC so the potentials are no more than standard 240V AC mains.

**** Update 1/2/2008 ************************
Changed down to 576V and 48 x 12V arrangement for the 20Ah batteries as I could not take full advantage of the regenerative braking. Power was being dumped to the braking resistor before batteries reached their max cyclic charge voltage of 15V.
Built prototype of pic-axe BMS and fitted to one module.

**** Update 13/3/2008 ************************
Louis Palmer (solartaxi) has now experienced the awesome regenerative braking of the Red Suzi ! I even fitted a 5W solarpanel on the bonnet so he would feel at home.
Look out for the solartaxi on it's world tour and Louis. He is a fantastic ambassador for EVs.

**** Update 25/5/2008 ************************
More info and pics at

code by jerry