Electric vehicle test:
VW Golf variant ECE
P.F. van Oorschot, R. Vos
DC 2010.036
DC report
Eindhoven University of Technology
Department of Mechanical Engineering
Dynamics and Control Group
Eindhoven, May, 2010
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This report describes the test results obtained during the test of an electric VW Golf variant. The
focus of the tests was to determine the energy consumption of the vehicle at different constant
speeds and during normal (sub)urban driving.
Test conditions The vehicle has been tested on the 21
st and 22
nd of April 2010. During the test the outside
temperature was 19 degrees Celsius at average. All tests have been performed with 2 persons in
the vehicle, weighing a total of 160kg. The tire inflation pressure was checked and put at the
prescribed pressure of 2.5 bar for the front wheels and 3.0 bar for the rear wheels.
All measurement data are based on the information display available in the vehicle. Due to the
limited time available, no calibration of the measured values has been done. The display provides
the following data: speed [km/h], power [kW], current [A], average energy consumption [Wh/km],
lowest cell voltage [V], highest cell temperature [°C] and motor temperature [°C].
Vehicle The vehicle tested is an electrified VW golf variant. The vehicle has been converted to a full
electric vehicle by ECE cars located in Lochem. Essent is the owner of the vehicle and agreed to
make the vehicle available for testing at the TU/e for two days.
Vehicle: VW Golf variant
License: 12-JND-2
Length/Width/Height: 4556/1781/1467 mm
Weight
The weight of the vehicle is measured on all wheels to determine the weight distribution. The
curb weight is measured without persons in the vehicle and is listed in table 1.
LF 390.0 kg RF 380.5 kg Front 770.5 kg
LR 410.5 kg RR 421.5 kg Rear 832.0 kg
Weight: 1602.5 kg
Front: 48.1 % Rear: 51.9 %
Table 1: Curb weight
The weight distribution is shifted to the rear compared to an original VW golf variant 1.6. This
leads to less under steer behaviour compared to the original vehicle. During driving no particular
behaviour has been observed. The total vehicle weight of 1602.5 kg is relatively high compared to
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the original VW weight of 1235kg. The conversion process increased the weight by 367.5 kg. To
compensate for the higher weight at the rear, extra support springs are mounted. As shown in
appendix III.
Drive train and components
The electric drive train of the vehicle consists of a conversion kit provided by AC Propulsion. The
motor is an air cooled 150kW AC induction motor. The motor is coupled to the original VW
gearbox, which is locked in second gear. During driving the motor reaches temperatures of up to
110 °C. The inverter, charger and DCDC converter are all integrated in a relatively large, air cooled,
box. The box is mounted in the original engine bay. The charger is able to charge up to 6kW DC
power, using 32A/230V AC power. The DCDC converter can deliver up to 100A of 12V power. The
datasheet of the AC Propulsion set can be found in appendix I. The interior heating of the vehicle
is provided by a 3kW external electric water heater, provided by MES-DEA. The air conditioning
pump is driven by an industrial air cooled electric motor.
Battery
The vehicle is equipped with a lithium ion battery pack with a total capacity of 37 kWh. From the
gathered data can be concluded that the usable capacity of the pack is 28 kWh, approximately
75% percent of the nominal capacity. The nominal voltage of the battery pack is around 330V, the
maximum current drawn from the batteries at full power is 460A. The voltage of the lowest cell
drops around 0.1V per 100A current drawn. During driving the temperature of the battery cells
reaches up to 48 °C. The complete battery is divided in two separate packs, one under the rear
seats and one in the trunk. The battery packs are air cooled.
Energy consumption The energy consumption of the vehicle is measured over a range of constant speeds up to 140
km/h, with increments of 10 km/h. The power consumption of auxiliaries and vehicle systems is
not dependant on the vehicle speed and is measured separately, during standstill. The power
consumption of these systems is listed in table 2.
Consumer Power
Vehicle systems only 0.3 kW
Vehicle Systems, lights 0.5 kW
Vehicle systems, lights, heating 3.5 kW
Vehicle systems, lights, air conditioning 4.1 kW
Table 2: power consumption of vehicle systems and auxiliaries
During the constant speed consumption test no auxiliaries are used, only the vehicle systems are
online. The results of the constant speed tests are listed in table 3.
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Power [kW] Consumption
Speed [km/h]
Trial
1 2 3 Average Wh/km
10 0.9 1 1 1.0 96.7
20 2.2 2.3 2.2 2.2 111.7
30 3 3.3 3.1 3.1 104.4
40 4.1 4 4.1 4.1 101.7
50 5.5 5.9 5.4 5.6 112.0
60 7.3 8 8.5 7.9 132.2
70 9.7 11.5 10.4 10.5 150.5
80 11 11.1 13 11.7 146.3
90 14 15 15.2 14.7 163.7
100 18.8 22 21.1 20.6 206.3
110 24 25.4 23.8 24.4 221.8
120 31 28.9 31.9 30.6 255.0
130 38.8 36.8 37.8 290.8
140 44 43 43.5 310.7
Table 3: Energy consumption at constant speed
As expected, the energy consumption increases rapidly at higher speeds. The vehicle drag is the
most important factor for the energy consumption at higher speeds. The use of auxiliaries such as
the heating or air conditioning has a large impact on the energy consumption of the vehicle.
Especially at low speeds, the power consumption of the auxiliaries is high relative to the traction
power. At a speed of 40 km/h the power consumption of the heating or air conditioning is as high
as the required traction power. At this speed the range of the vehicle is split in half when the
heating or air-conditioning is used. Figure 1 shows the energy consumption characteristics with
and without auxiliary loads. This clearly shows the negative influence of auxiliaries on the energy
consumption and range at low speeds.
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Figure 1: Energy consumption characteristics at constant speed, with and without heating
Energy consumption during (extra)urban driving.
To determine the average energy consumption during (extra)urban driving a specific route is
driven. The route is chosen as a representative route for driving in the Netherlands. During driving
the speed is kept close to the speed limit. The route has a length of 26.2 km of which 36% is
highway, 23% is suburban roads and 41% km is urban traffic. The route is driven in 38 minutes, at
an average speed of 42 km/h. The average energy consumption over the route is 230 Wh/km.
Considering the 28 kWh usable capacity of the battery this results in an average range of 122 km.
Table 4 shows the average consumption measurements during the tests, as well as the
percentage of regenerative braking. A description of the complete route can be found in
appendix II.
Trial
1 2 3 Average
Distance 26.2 26.2 26.2 26.2 km
Energy 6.0 6.0 6.1 6.0 kWh
Regenerative 7.4 8.4 9.8 8.5 %
Consumption 229 230 232 230 Wh/km
Table 4: Average consumption during suburban driving
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Performance The performance of the vehicle has been measured. The acceleration performance of the vehicle
is good at high speeds, but quite slow at low speeds. The reason for this is a software limit on the
motor torque at low speeds. Table 5 shows the acceleration performance at different speeds.
Time [s]
Acceleration
Trial
1 2 3 4 Average
0-50 km/h 7.1 7.3 7 7.1 s
0-100 km/h 13.8 14 14 13.5 13.8 s
50-80 km/h 3.9 4.3 3.9 4 4.0 s
80-120 km/h 6.6 6.4 6.4 6.5 s
Table 5: Acceleration performance
The top speed of the vehicle is limited to 140 km/h.
Regenerative braking
The regenerative braking performance of the vehicle has been measured at different speeds. The
vehicle utilizes regenerative braking only on release of the throttle pedal. The brake pedal does
not influence the regenerative braking power and only controls the hydraulic brake system. The
regenerative braking power is surprisingly low compared to the maximum traction power of 150
kW. Table 6 shows the regenerative brake power at different speeds.
Power [kW]
Speed [km/h]
Trial
1 2 3 Average
50 7.3 7.3 7.2 7.3 kW
80 11 11.5 12.2 11.6 kW
100 14.3 15.2 15.6 15.0 kW
120 19 19.5 19.2 19.2 kW
Table 6: Regenerative braking power
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Appendix I: AC Propulsion set datasheets
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Appendix I
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Appendix I
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Appendix II: (sub)urban route for consumption tests
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Appendix II
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Appendix II
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Appendix III: Pictures of vehicle and component location
All pictures can be found at:
\\Wtbfiler\control systems technology\VDL\Studenten\projects\VW Golf ECE test
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Appendix III
