EPA-AA-TAEB 75-3
Performance of the Electrosport
Electric Vehicle
June 1974
Technology Assessment and Evaluation Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
Environmental Protection Agency
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Background
The Electric Fuel Propulsion (EFP) Company of Ferndale, Michigan,
has been converting conventionally powered vehicles to electric
power. EFP does the required design work, fabricates system
components as necessary and installs the system in a vehicle.
The Special Vehicle Program Branch of th.e Advanced Automotive
Power Systems Development Division contracted with EFP (con-
tract #EH SH-71-008) for the use of a prototype vehicle to
evaluate its performance. The test of the vehicle reported herein
was conducted over a one-year period from August 1972 to July 1973,
The performance tests were conducted by the Test and Evaluation
Branch of the Emission Control Technology Division in support of
the Special Vehicle Programs Branch.
Vehicle Description
The car tested for this project was an American Motors (AMC)
Hornet station wagon modified for electric operation by EFP.
The engine usually installed in this vehicle is either a 258
CID 6-cylinder or a 360 CIDV-8 gasoline fueled internal com-
bustion engine.
The EFP designed electric power system installed in the vehicle
consists of a 20 hp Porter 144 volt D.C. motor1, control 'circuits,
and twenty-four 6-yolt lead-acidJbatteries in series. The motor
uses a separately excited shunt field and is installed in the
standard engine position. The batteries were placed in the front
in the engine compartment, at the rear under the floor, and under
the rear seat. The standard vehicle manual transmission (with
ratios of 2.548, 1.558, and 1:1) and rear axle (4.44:1 ratio)
were used. Additional control circuits protect the motor and
step down the battery voltage to the vehicle operating require-
ments. Power is controlled by the standard foot pedal. Battery
charging used 220 V and takes about 6 hours to fully recharge
the batteries.
The curb weight of the car in stock condition is 2830 pounds
with the 6-cylirider engine and 3060 pounds with the V-8 engine.
The electric-powered vehicle weighed 5260 pounds, due to the
battery weight. Vehicle instrumentation consisted of an amp-hour
meter, battery and motor volt and amp meters, motor speed and
motor pyrometer (temperature). All lab testing was done at an
inertia weight of 586,0 pounds to duplicate road test weights.
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Test Program
The car arrived at the Ann Arbor laboratory on August 18, 1972.
After initial checkout and familiarization, the car was taken to
the Dana test track at Ottawa, Michigan, for performance testing.
Due to vehicle problems these tests were not completed until
January. Other EFP commitments for the car prevented completion
of laboratory testing until July 1973. The vehicle was tested for
acceleration, steady state range, transient range, power, per-
formance at partial battery charge, and energy economy.
Road performance testing was done by Dana at their track under
an EPA contract. The Dana test track is a 1 3/4-mile concrete
oval with a design speed of 60 mph. The vehicle speed and
mileage were measured with a calibrated 5th wheel. Vehicle
braking distance was recorded by using detonators to mark start
and stop of braking. For performance at partial charge, the
vehicle's amp-hour meter was used to indicate state of charge.
Recharge energy was measured with a three-phase power meter
connected in series with the battery charger.
Vehicle acceleration runs were done with the batteries both fully
charged and 801 discharged. Maximum speed capability mileage tests
were a repetitive cycle using the motor current-time limits to
set vehicle speed.
For transient range the vehicle steady state power requirements
were duplicated on a chassis dynamometer. The Federal Driving
Cycle was used and end of range determined when the vehicle could
no longer follow the velocity profile.
* . •
Results and Discussion
Results of the performance tests are detailed in the Appendix
for both the road and dynamometer tests, and are summarized below.
The average of three tests at each speed gave these results:
Vehicle Range at Constant Speed
• . • ' ' '• !
MPH MILES RECHARGE K-W HOURS
28.8 64.9 21.5
42.8 47.1 18.2
60.7 34.0 15.2
These results are plotted as energy economy and'distance vs.
speed in Figures 1 and 2 respectively. The K-W hour values for
these tests are suspect. A comparison with previous tests (Ref.l)
shows that previously the vehicle was able to travel about 40%
further, although it consumed about 301 more kilowatt-hours per
miles.
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For the transient range tests both the standard dynamometer road
load and test road load data (Table I) were used. The results are
VEHICLE RANGE ON FEDERAL DRIVING CYCLE
Date
2-7*
2-12*
2-20*
6-21*
7-3**
Mileage
30.0
37.5
25.7
22.6
25.0
*Standard road load for 5500 Ib. vehicle is 13.9 hp at 50 mph,
per Federal Test Procedure
**Vehicle road load curve
To obtain vehicle range over a transient driving cycle it is
important to use an accurate road load curve, since a battery's
energy capacity is strongly dependent on its discharge rate.
Therefore, the EFP vehicle's actual road load horsepower was
also used for a range test on July 3. Results were comparable
to the two previous tests. This road load curve and the actual
dynamometer curve are listed in Table Ii They are in reasonably
close agreement.
MPH (vehicle)
TABLE' I
Vehicle Horsepower
HP Delivered HP Required
HP dyno
10
20
30
40
50
3.4
6.4
8.0
12.9
21.1
2.4
5.5
9.7
15.5
23.7
2.0
4.9
9.3
15.6
22.8
Delivered HP is calculated from the motor current and voltage
requirements during steady state road tests. HP dyno is the
horsepower delivered to the dynamometer with corrections made
for rear wheel and drivetrain losses. HP required is an esti-
mated value for the vehicle weight and frontal area.
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The acceleration tests (figure 3) showed a marked increase
in acceleration times for the 80% discharged battery com-
pared to the fully-charged condition. The car took about
twice as long to reach a given speed. These results do
not reflect the best performance the vehicle is capable
of due to difficulties experienced in the upshifting of
the manual transmission. The difficulty may have been
worn transmission synchronizers. No attempt was made
to repair the transmission.
When operated at maximum speed the car went 53*6 miles
at an average speed of 35.7 mph. In braking tests the
car stopped in 75 ft. at 40 mph and in 173 ft. at 60 mph.
Maximum speed on a 5% grade was 40 mph when 65% charged
and 30 mph when 35% charged.
The vehicle recharge energy was measured with a standard
building kilowatt hour meter. Apparently it was unsuitable
for accurately measuring the charging energy since the
batteries and charger present an unusual load and power
factor to it. An indication of this is the road test of
June 25. The power used by the motor, calculated over the
entire route, is 12.8 KW-hrs. Yet the indicated recharge
energy of 14 KW-hrs infers a charge/discharge efficiency
of 91%. This is considerably higher than the 70% efficiency
that could reasonably be expected from experience with other
battery systems. Also, when the charger was adjusted for low
current draws (15 amps at 200 volts) the meter would indicate.
no energy consumption even after several hours.
During the vehicle dynamometer testing there were considerable
odors during heavy load conditions. This was probably either
hot insulation or gases from the rapidly discharging batteries
Momentary power cutbacks also occurred, probably due to the
motor thermal protective device. The vehicle also seemed to
operate at times in an anamolous fashion - two widely varying
power consumptions under identical conditions. The tests on
June 25 showed 40% changes in power consumption from lap to
lap at both 20 and 30 mph. The vehicle would operate at a
certain level of current and voltage for a lap and then
suddenly change 40% and hold the new setting, while the
vehicle neither accelerated nor decelerated.
©verall vehicle handling was poor. The car weighed 65% more
•than the standard car and most of the additional weight was
at the front and rear of the car. Therefore, steering was
extremely poor. Also, the required oversize springs were not
tuned to the vehicle suspension.
Prior to EPA testing, EFP conducted extensive tests at Dana.
These tests (Ref. 1) were conducted in accordance with the
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"Specifications for Battery Powered Electric Multi-purpose
Work Vehicles" of the Electric Vehicle Council, February 1972
(Ref. 2) . These specifications are for battery powered,
multi-purpose work vehicles for use by the electric utility
industry, public agencies, and private corporations. In
general the vehicle easily met the performance requirements.
However, during the testing by EPA, vehicle performance did
not meet these same standards. The only major vehicle change
between the EFP and EPA tests was a complete battery change
after the start of EPA's track testing, which should have
improved performance.
These tests of the electric vehicle showed that the car was
capable of light duty city-suburban use. However, considerable
improvements in handling would be necessary before the vehicle
was safe to drive.
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REFERENCES
1. William F. Volk, "Performance Tests of Electric Fuel
Propulsions Electrosport Electric Vehicle," Dana
Laboratory Report #599 for Electric Fuel Propulsion.
2. "Specifications for Battery Powered Electric Multi-purpose
Work Vehicles," February 1972, Electric Vehicle Council.
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10
APPENDIX
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11
EFP ELECTROSPORT
To Drive:
Start in First Gear, drive in First Gear between
0 and 25 mph.
Drive in Second Gear between 26 and 45 mph.
Drive in Third Gear over 45 mph.
Manual Transmission - Use clutch to change gears.
Current Limit on DC Motor:
150 amps continuous
200 amps for 10 minutes
300 amps for 5 minutes
Starting surge currents are as high as 1000 amps.
Recharging the Batteries:
Maximum Charging Potential 175 volts
Maximum Charging Current 200 amps
Electrosport
February 20, 1973
Battery Voltage Indicated amp Battery
Miles* Start Stop hours in battery Temp.
7.45 155 142 225 74°F
7.35 142 140
7.35 140 140
3.55** 140 139 85 90°F
Net 25.7 miles
*Federal Driving Cycle
**Loss in acceleration at 360 seconds, test was 505 seconds
duration.
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12
Mileage Electrosport
June 21, 1973
Battery chg.(corrected) 1265 Start
Battery temp. 75°F
Amp-hours 0
Mileage 0000.0
Motor case temp, (end of run)
Tire pressure 45 psi
Inertia wt. 5500 Ibs.
Battery chg.(corrected) 1240 End 1st LA-4
Battery temp. 80°F
Amp-hrs.35
Mileage 7.85
Motor case temp. 120°F
Net mileage 7.85 miles
Battery chg.(corrected) 1197 End 2nd LA~4
Battery temp. 85°F
Amp-hrs. 67.5
Mileage 15.55
Motor case temp. 145°F
Net mileage 7.7 miles
Fnrl ^1-rI T A - d
Battery chg. (corrected) 1134 cna <5ra LA *
Battery temp. 90°F
Amjp-hrs 112.5
Mileage 22.55
Motor case temp. 160°F
Net Mileage 7 miles
Unable to keep up with road speed trace
recharge 13.4 kw hr•(this measurement is in error)
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TABLE II
CONSTANT SPEED POWER REQUIREMENTS
Road Data June 25
Dynamometer Data
MPH MPH Battery
Indicated Actual Amps Volts
10
20
30
35
40
45
50
55
60
66
10
20
31
36
41
47
52
55
55
.0 97
.5 100
.1 112
.3
.7 127
.0
.3 197
• 8
.8 237
26
48
53
76
80
100
Watts
2522
4800
5936
9652
15700
23700
34800
HP
at motor
•3.4
6.4
8.0
12.9
2.1 . 1
31.8
46.7
** Dyn°
Dyno Torque
HP est? HP cal. cal.
2.4
5.5
9.7
12.3
15.5
19.3
23.7
28.9
1.3
3.1
6.0
. 8.1
10.7
13.8
17.6
22 . 2
94
113
146
167
192
220
252
288
Dyno
Torque
Set
65
90
135
162
195
213
237
264
Dyno
HP
Set
.9
2.5
5.6
7.9
10.8
13.3
16.5
20.3
HP *
Dyno
2.0
4.9
9.3
12.1
15.6
18.8
22.8
27.0
HP - TV/750 T = dyno torque, V = mph
*HP estimated'-^ f(.015) (5840) + (.0015) (20) V2J
**Dyno HP cal. -3ys £ (.015)(2720) * (.0015)(20) V2}
***Includes rear wheel losses
HP (at motor) does not include driveline efficiency (95t)
Weight = 5840 Ibs.
Frontal area: 20 sq. ft.
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14
Road Loads - Electrosport
June 25, 1973, at Dana Test Track
Tire pressure 33 psi
3 people in vehicle
total mileage 44 miles
26 laps of 1.75 miles
recharge 14.0 kw hr (this measurement is in error)
0-25 1st gear
25-45 2nd gear
45 up 3rd gear
Test Series #1
Battery
Battery
Battery
Battery
Battery
Temperature
Speed-
ometer
MPH Direction
specific gravity 1275 (corrected)
specific gravity 1247 (corrected)
temperature 80°F at start
temperature 85°F at end
amp-hours 0 at start, 25 at end
SE 6-8 knots
at
at
start
end
82°F,' wind
10
10
20
20
30
30*-
30
30
30
40
40
50
50
60
60
W
E
W
E
W
E
W
E
W
E
W
E
W
E
W
DC Amps
90-95
100
100
100
105
155
105
120
101
135
;120
200
195
245
230
DC Volts
25-26
27.5
47.5
48
56
60
50
56
51
79 '
73
81
80
100
99
RPM
1250
1350 '
2350
2325
2075
2150
2100
2150
2775
2900
2300
2450
2650
2700
Motor
Temp.
80°F
85°F
87°F
87°F
89°F
89°F
90°F
92°F
92°F
92°F
93°F
95°F
95°F
95°F
Test Series #2
Battery specific gravity 1247 (corrected) at start
Battery specific gravity 1193 (corrected) at end
Battery temperature 85°F at start
Battery temperature 87 °F at end
Battery Amp-hours 25 at start, 81 at end
Temperature 86°F: wind, east 4 knots at end'
10
10
10
20*-
20*
20
20*
2.0
E
W
E
W
E
W
E
E
91
95
93
59
42
95
78
95
28.5
27.5
27.2
45
44
45.
39
41
1850(?)
1350
1350
2350
2300
2350
2300
2450
103°F
107?F
105°F
103°F
100°F
100°F
100°F
10.0°F
*Anomalous data points
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15
Speed-
ometer
MPH
Direction
DC Amps
DC Volts
RPM
Motor
Temp.
30
30
40
40
50
50
50
60
60
63
66
66
W
E
W
E
W
W
E
W
E
W
E
W
150
125
133
155
225
236
260
240
240
330
305
295
59
55
70.1
77
80
81
84
95
93
109
118
114
2150
2175
2700
2800
2300
2325
2300
2700
2675
2900
3000
3000
102°F
99°F
99°F
97°F
95°F
98°F
97°F
97°F
97°F
97°F
Test Series #3
Battery specific gravity 1193' (corrected) at start
Battery specific gravity 1156 (corrected) at end
Battery temperature 87°F at start
Battery Temperature 93°F at end
Battery AMP-Hours 81 at start, 108 at end
Temperature 84°F wind East 8-12 knots at end
10
10
20
20
30
30(29)
40
40
50
50
52
51
E
W
E
W
E
W
E
W
E
W
E
W
90
83
85
75
122
102
173
135
230
215
240
223
26,
25
45
43
55
47
85
74
83
79
84
79
1350
1350
2300
2300
2150
2180
2825
2800
2300
2300
2375
2375
125°F
125°F
115°F
115°F
113°F
108°F
108°F
105°F
105 °F,
105°F
105 °F
105°F
Test Series #4
2 laps maximum speed attainable 45 and 35 mph
Battery specific gravity 1156 (corrected) at start
Battery specific gravity 1125 (corrected) at end
Battery temperature 93°F at start
Battery temperature at end
Battery AMP-Hours 108 at start, 125 at end
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16
Electrosport
June 28, 1973
Tire pressure 45 psi
Recharge 3 kw hr
Battery specific gravity 1280 at start
Battery temperature 76°F at start
Amp hour at start 0
0-25 mph 1st gear
25-45 mph 2nd gear
45 up mph 3rd gear
.le dyno
iph mph
10 10.5
20 21
30 31.5
40 42.0
50 53.0
60 63.5
amp hour
10 10.5
20 21
30 31.5
40 42
50 52.5
60 63.5
Battery
Battery
Amp hour
10 10.5
20 21
30 31.5
40 42.0
50 52.5
60 63.5
batt
volts
146
146
146
143
140
135
15
146
141
146
144
139
133
batt
amp s
26
46
55
85/70
123
195
50
100 (?)
58
86
137
224
motor
volts
29.5
50
53.5
73/68
76
98
39.5
70
51
71
77.5
100
motor
amps
97
98
112
125
195
235
93
98
110
130
193
220
torque
ft/lbs
30
56
24
54/22
92
164
50
65
45
70
119
21,
specific gravity 1263
temperature 76 °F
30
147
145
142
140
134
131
30
47
76
115
180
218
32
53
61
82
86
99
104
102
130
140
213
215
85
175
100-105
138
199
194
Battery Specific gravity 1244
Battery temperature 78°F
Amp hour 48
HP = Torque (ft. Ibs.) X Velocity (MPH)
750
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17
Electrosport
July 2, 1973
Tire pressure 45 psi
Battery specific gravity 1275
recharge 4 kw hr
battery temperature 75°F
amp hours 0
Level Road Load
vehicle dyno batt.
mph mph volts
10
20
30
40
50
60
10.5
20.5
31
41
52
61.5
147
146
143
140
134
130
batt
amps
62
52
95
135
233
270
amp hours 21
Road load with 5% grade
10 10
20 19.5
30 30
40 38.5
142
136
126
118
87
190
300 +
300 +
battery specific gravity 1225
battery temperature 85°F
amp hours 43
Level road load
10
20 20
30 31
40
50
60
10.5
41
53
64
147
145
140.5
136
126
51
49
90
144
260
Road load with 5% grade
10 10
20 19.5
30 31
135
123
90
105
185
battery specific gravity 1190
battery temperature 90°F
amp hours 75
Level road load
10 10
20 20.2
30 31
142
140
124
52
48
83
motor
volts
30.5
57
64
85
88-91
98
47
79
88
116
27
48
64
86,
93
59
79
88
26
50
63
motor
amps
102
115
162
178
275
285
torque
ft/lbs,
48-50
90
146
188
261
271
238
250
385
410
600
640
690
777
98
111
172
200
315
375
240
250
390
48
81
150
200
277
350
590
634
699
90
100
152
46
89
147
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18
Electrosport, July 2, 1973 continued:
40 40.5 112 153 82 170 190
40+ 42.5 85.5 200 88 190 207
battery specific gravity 1165
battery temperature 92 °F
amp hours 83
Torque (ft. Ibs.) X Velocity (MPH)
750
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19
Start
End 1st LA-4
Mileage Electrosport
July 3, 1973
Battery chg. (corrected) 1277
Battery temp. 72°F
Amp hours recharge 12 kw hr
Mileage 0000.0
Motor case temp. 72°F
Tire pressure 45 psi
Inertia wt. 5500 Ibs.
Battery chg. (corrected) 1242
Battery temp. 82°F
Amp hours 25
Mileage 7.8
Motor case temp.
Net mileage 7.85 miles
Battery chg. (corrected) 1215
Battery temp. 90°F
Amp hours 60
Mileage 15.5
Motor case temp. 140°F
Net mileage 7.35 miles
Battery chg. (corrected) 1163 End 3rd LA-4
Battery temp. 100°F
Amp hours 103
Mileage 22.4
Motor case temp. 160°F
Net mileage 7.25 miles
Unable to keep up with road speed trace at end 10 min,
End 2nd LA-4
Battery chg. (corrected) 1150
Battery temp. 95°F
Amp hours 115
Mileage 25.0
Motor case temp. 155°F
Net mileage 2.6 miles
Maximum speed 41 mph
28 mph
20 mph
End 4th LA-4
57 mph desired
35 mph desired
30 mph desired
Test terminated after 440 seconds
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