Expensive and limited, just as the first personal computers, the first factory-built electric vehicles are selling slowly.
A change coming this year, though, will make new models more attractive, say advocates, the way MMX chips are supplanting Pentiums, or, to pick a metaphor from the parallel era of computing, as Windows is replacing DOS.
The question for car companies is whether the change, which will increase travel range but at a price higher than that of older batteries, is enough to spur another round of buying, production and research.
The change is to swap nickel-metal-hydride batteries, or NiMHs, for the lead-acid kind. The battery that will make the electric car common is probably still on the drawing board, but the NiMH could greatly extend range and will go into General Motors’ EV-1 sedan and the S-10 pickup this year. It is already turning up in a car from American Honda Motor.
NiMHs have been used in laptop computers for years but are not mass-produced in packs big enough for cars. GM Ovonic, a venture of General Motors and the Michigan company that invented the batteries, is producing about one battery pack a day and plans to expand this year.
The NiMH can offer range because it has about twice the energy density of the lead-acid battery. Lead-acid batteries, used to start conventional cars, carry about 35 watts of energy a kilo, meaning it would take about 3 kilos of battery–nearly 10 pounds–to keep a 100-watt bulb lighted an hour. The NiMH carries 70.
That is paltry compared with the industry’s goal of 200 watt-hours a kilo. But it raises the possibility of doubling the EV-1’s range from its current 70 to 90 miles.
GM hasn’t said what a car with NiMH batteries would cost, but it is significantly more than the lead-acid version, which seems too high for popular taste.
Last October, GM began offering the EV-1 in California and Arizona on a 36-month lease at a range of $480 to $640 a month. In May, it cut the price to $400 to $550.
Honda markets an electric vehicle in California with the NiMH. The four-passenger EV Plus leases for $499 a month, but Honda expects slow sales.
Former GM Chairman Robert Stempel, who now heads Ovonic Battery and its parent company, Energy Conversion Devices of Troy, Mich., said the next task is to determine how much range consumers are comfortable with.
If a driver doesn’t want more than 120 miles, designers could save weight, space and price by removing some batteries.
The EV-1’s lead-acid battery pack weighs more than 1,100 pounds, though it contains fewer than 17 kilowatt hours, less electricity than the typical American house uses in a day. The energy equivalent is less than 1.5 gallons of gasoline.
The NiMH can provide the same amount of energy at 550 pounds. And a lighter EV-1, with the same 17 kilowatt-hours, would go farther.
Nancy Hazard, organizer of the annual American Tour de Sol race of electric vehicles, which in May was swept by cars with NiMH batteries, said that with lead-acid batteries, automakers have to cram in as many as possible to get minimally acceptable range. But the NiMH, she said, presents the industry with the problem of striking the right balance of performance and price.
Proponents say the NiMH can last through more recharging cycles than the lead-acid battery and thus may cost less per mile.
In contrast, lead-acid batteries are certain to need replacement every two or three years as they wear out.
So far, though, consumers do not like the price-performance combination on the EV-1 as much as they like the MMX.
