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

Preparations for 1997 American Tour de Sol
Electric Commuter Vehicle Evaluation in Connecticut
Record of Preparations for Resumption of Commuter Evaluation and 1997 ATdS
March 19, 1997: Consultation with an engineering consultant included their modeling of energy use for
the electric vehicle with a variety of possible batteries. It was determined that the Horizon battery pack
could not be replaced with GNB batteries. GNB is a valve-regulated lead-acid battery with the following
attributes: 170 W/kg, 85 Ah capacity, 35 Wh/kg, 85 Wh/l, 12 V, 29.1 kg per battery, and >400-cycle life
at 70% DOD.[1] The low peak power of GNB was not projected to be able to provide the power
necessary to climb hilly terrain during the second half of the discharge cycle. Also, the battery company
could not provide a warrantee that met the needs of the Rideshare Co. Another battery, produced by
Exide, was considered and rejected because its 80 Ah and power discharge characteristics were found to
be unsuitable for hilly terrain in the consultant's vehicle-model projections.
Nominally, the attributes of the Horizon batteries appeared essential to the success of the electric vehicle.
The vehicle was designed to utilize Horizon batteries with 95 Ah. The battery manufacturer is not
currently producing this battery model and it was necessary to obtain thirteen 85 Ah Horizon batteries
from the company. The 85 Ah Horizon battery is a smaller battery, but has improved chemistry. They are
anticipated to provide the capability to expend bursts of energy late in its discharge cycle (near the
vehicle's maximum range), as for passing and hill climbing. This capability is anticipated to be essential
for the terrain of the route through the White Mountains of New Hampshire.
Arrangements were made to utilize and evaluate a higher-output battery charger, also. The vehicle comes
equipped with a 3 kw 'smart' charger that draws a nominal 20 Amps on a 220 Volt circuit. A
higher-output charger "10 kw charger" will provide a 5-9 kw charging rate, drawing either 30 or 50 Amps
at 220 Volts. The 10 kw charger is compatible with the vehicle's computerized battery management
system and according to our EV consultant, recent experience suggests that a higher charging rate is
related to longer lived, 'healthier' batteries. It is anticipated the higher-rate charger will be advantageous
because it provides quicker 'fill-ups.' The charger evaluation was anticipated to last several months.
The vehicle manufacturer recently agreed to loan the Rideshare Co. a NESEA-compliant Watt Meter for
the 1997 Tour de Sol, as was provided in 1996. Goodyear Tire and Rubber supplied new high pressure,
low rolling-resistance tires. Wheel alignment and the brakes were inspected and adjusted to ensure
optimal safety and efficiency.
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[1] Reisner, D. E., "Commercial Off-the-Shelf (COTS) Batteries for Motive Power," US NANOCORP,
Inc., North Haven, CT, 1996.
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