104 HawkersBridgeboardPrius packBoom!
OwnerMike Phillips
Owner's Other EV1994 Chevrolet S-10
LocationSan Jose, California United States map
Web/EmailWebPage email image
Vehicle1994 Chevrolet S-10 longbed
This truck was assembled by the College of San Mateo and supervised by USE in 1996. Later a tilt bed was added.

This is my #1 USE truck.
MotorSiemens 3-Phase AC
50kw peak stock, 80kw peak modified, 16kw continuous, water cooled.
Drivetrain50-80kw 3 phase system named Dolphin by Hughes Aircraft. Water cooled motor and power electronics. Manual 5 speed Borg Warner T10 locked in 2nd gear from the USE factory. 4.11 rear axle.
ControllerHughes Dolphin
Three phase output. Normal max current draw from the pack is 180 amps. Software was changed to increase it 240 amps. Regen also capable of pushing up to 240 amps into the pack. Measured improvement in efficiency due to having regen is 25-42% !!
Batteries251 Saft BB600, 1.20 Volt, Nickel-Cadmium, Flooded
Right now 251 cells are in circuit to allow the 400v charge max to keep the current up enough to properly overcharge these cells. They require 20-40% overcharge to actually achieve 100% charge of both cell plates per the manual.

This pack has already paid for itself in gasoline savings, plus paid for 33% of the purchase price of the truck. That's why I picked them over lithium at the time.

Previous packs:
104 lead acid Hawkers
5 Prius packs in parallel.
Lithium test cells.
System Voltage312 Volts
ChargerHughes Dolphin
Factory built in 3kw charger using factory motor and igbt's to boost voltage. With appropriate changes to software, is able to charge lead acid, nimh, or nicad battery chemistries. 400v max output. Automatically charges from 120/208/240. Factory on board step down transformer allows for greater charging opportunities.
Heater2500 watt semi truck block heater used to heat the factory GM heater core.

Upgraded to Kim Hotstart brand of water heater. It's now about 2.5kw worth of heating. Warms cabin up much faster now!! One mounting tab of the Hotstart was machined off so it would mount in the factory box.
DC/DC ConverterDolphin Factory dc-dc from Hughes Aircraft.
100amp peak, 13.5-14.4v output. Analog hardware controlled.
Instrumentationsoc, temp, Emeter (amps, volts, ahr's, kwhr's). The software provides data from the built in data logger in the Dolphin hardware. There is basically no limit on info that can be taken from this system during driving or charging.
Top Speed72 MPH (115 KPH)
Electronically regulated top speed due to motor limit of 9000 rpm.
Range40 Miles (64 Kilometers)
Have driven it twice to 40 miles. But that's too hard on the pack. So it is taken to 30 miles only when needed.
Watt Hours/Mile225 Wh/Mile
200-250 summer/250-275 winter, as measured from the Emeter. Use to be 350-400 whr/mile with 1700lb lead acid pack. Now 250whr/mile with nicads. Right around 1000lbs lighter with nicads. Also depends on outdoor temperatures and wind. Warmer temps allow for better efficiency.

A recent(Aug '07) front end alignment setting the toe to zero, and changing the rear end and transmission fluids to synthetic has netted at least 10% better efficiency!

Best efficiency to date was 178 watt-hours per mile during work commute.

Going to the Palo Alto EV Rally with 300lbs of cargo and 200lb driver, the truck gets 200 wh/mi on the freeway at 45mph weighing 4400lbs. That is great efficiency!
EV Miles
Start:3,765 Miles (6,057 Kilometers)
Current:22,800 Miles (36,685 Kilometers)
Total:19,035 Miles (30,627 Kilometers)
    As of 2/11/2011
Seating Capacity3
Curb Weight3,900 Pounds (1,772 Kilograms)
As measured on a digital truck scale, without driver(234lbs). This truck is 1000 lbs lighter than with the stock trucks with 52 lead acid batteries. It rides much nicer and accelerates far better now.
TiresViva2 low rolling resistance tires by Goodyear. Sold only at Walmart. 44 psi stock, running them at 50 psi.
Conversion TimeFactory built. Required circuit board repair and major debug time to make operational.
Additional FeaturesThe current nicad pack has been estimated by a NASA scientist to achieve 50k miles if 50% soc is generally not exceeded. Although the pack does take watering, the cost of cell replacement is far higher than water. So it's worth the watering. The watering schedule is every 3k miles. It appears that the KOH concentration is related to capacity and longevity. Specific gravity should be maintained from 1.275-1.325.

12/2007 - A test module of 10 to 20 A123 Lithium cells in parallel is being designed for being driven within the nicad pack. The Lithium cells will have their own monitoring/management system.

2009 - Three Thundersky 40ah Lithium cells did fine with several hundred miles of road tests. They held up with no noticeable drop in pack impedance. A full pack of these cells would be required for a comprehensive test, to determine what operational impedance they really have.

There are 27 nicad cells that are a different rating than the rest of the pack. These cells have less capacity and therefor limit range. The plan is to replace these lower capacity nicads with the A123 Lithium modules.

12/2010 Found 2 shorted cells and one very low on water. Pack is working better now as it had very short range. The total capacity is 7kwh now (30 miles). Was 9 kwh when new(40 miles). The pack now has about 15k miles on it.
This truck had several circuit boards destroyed or damaged from the 12v aux battery being connected backwards by a previous owner. I've made the necessary repairs and the truck runs fine. I'm now able to professionally repair the main, dc-dc and charger boards used in all US Electricar vehicles. I own and operate a world wide motor control repair business.

Future upgrades will include using Coroplast to seal the under carriage for better aerodynamics.

It's used as my main daily transportation. I have a Honda Accord for long range requirements.

Now I have a 2002 Honda Insight that gets 50-103mpg for longer range needs!

Modified the Dolphin to put out 70kw from it normal 50kw. More is possible.

I've started a site dedicated to helping USE vehicle owners. Please visit USElectricar.net.

code by jerry