Evaluation of Electric Vehicles as an Alternative for Work Trip and ...

ALAB Car Evaluation Completed
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Electric Commuter Vehicle Evaluation in Connecticut
1998 - Final Year of ALAB Evaluation
Discussions took place about the future of the electric vehicle in this project. An
energy budget model for a fuel-cell hybrid was prepared by engineers at Neocon
Technologies in December, 1997. The model addressed the effect on driving-range
extension of a small power generator. A small fuel cell outputting a constant 1.2 kW
showed a potential to extend the range between 70 and 150 miles above it's
demonstrated 60-70 miles between charges, assuming the vehicle was driven on flat
terrain at 30-35 mph.
There was interest in the concept of extending the range of the vehicle to a more
practical 150-200 miles between recharging while maintaining zero emissions. A
small fuel cell would be more affordable than a large unit and may have practical
application as an EV range extender. The computerized battery management system
can be configured to turn the fuel cell on and off in relation to the battery
charge/recharge state.
Another possibility was to use a larger 5 kWh fuel cell combined with a smaller
battery or a capacitor.
A third possibility was to utilize the vehicle as a test bed for a different battery with
the potential to provide not less than a 100-mile range, as it appears this will be
required for small EVs to be viable state fleet cars in Connecticut.
OUTCOME --
● One battery with excellent characteristics is the Lithium-ion battery. The battery, still
in prototype at battery manufacturers, has a specific energy that is 120 Watt-hours per
kilogram, 140% higher that the specific energy of a Nickel-cadmium battery. The
implication is that range of our typical subcompact EV could increase from 70 miles
to over 210 miles for the same weight of batteries carried in the car. This would
almost certainly provide for most in-state daily driving-range needs of state
employees. Unfortunately, the Li-ion battery is not anticipated to be in production
until 2005 and pricing is undefined.
● Another battery with very good characteristics is the Nickel-metal Hydride (NiMH)
battery. The battery, which went into production in November 1998 at the Ovonics
company, provides 70 Watt-hours per kilogram, 40% greater power storage capacity
that the NiCd battery. Unfortunately the 40% increase in specific energy cost 392%
more than the NiCd battery. The range of the Solectria Force subcompact has been
established by others (Boston Edison for example) and is about 90 miles in daily
driving for a 16 kWh battery pack (253 kg), which is 61 kg lighter than the 15 kWh
NiCd (314 kg). Others have installed more of the lighter weight NiMH batteries in
the Solectria Force to achieve longer driving range. If the car carried 23,300 Wh (314
kg) of NiMH batteries, the range of the car would be approximately 130 miles.
● In November 1998 we learned that the New Jersey DOT had contracted with a fuel
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