Dose of reality needed for battery range claims

Promises of 500 km for Tesla's coming Model S have strings attached

Oct 31, 2009

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SPECIAL TO THE STAR

The deeper I drive into the world of electric vehicles, the more uncertainties I encounter.

The industry is in a sort of phony war stage – plenty of hype, claims of technical advances leapfrogging one another, and stimulus cash by the bushel – with almost nothing actually on the road.

This week, my virtual tour of EV manufacturers pulled up to Tesla Motors, the California company that does have all-battery cars in use, about 900 of its Roadsters.

The Roadster – based on the Lotus Elise, with gas tank and engine replaced by electric motor and 6,600 lithium-ion battery cells weighing 450 kilograms – is getting mostly positive reviews.

But eye-popping and high-tech as it is, at $109,000 (all figures U.S.) and with only two tight seats, it's a rich boys' toy that will remain a mere curiosity among the millions of cars on North American roads.

Potentially more interesting is Tesla's second-generation car, the Model S, due in a couple of years. It's billed as a $57,400 vehicle able to carry five adults (and two kids in a rear-facing jump seat) up to 500 kilometres on a full charge. That puts it near the front of the range sweepstakes, although its price is much higher than that being proposed by its main competitor in the distance department, China's BYD.

Range claims, of course, are just smoke until they're confirmed by long-term driving in the real world, and here Tesla has a credibility advantage. Roadster drivers report around 250 kilometres per charge. That's less than the stated 400, but not shabby considering that the car's design and performance tempt owners into foot-stomping acceleration, high speeds and aggressive manoeuvring. That style puts a bigger drain on the battery pack than does the more sedate driving patterns of the official U.S. Environmental Protection Agency tests.

If the Model S added 100 kilometres or so to that range, it would be pretty useful. But a dose of reality is in order. The $57,400 version will be rated at just 240 km using EPA test procedures.

Tesla is, so far, unique in promising to offer optional battery packs. One is said to boost the range to 370 kilometres. The most expensive will be rated at 500.

No prices for those upgrades are available yet, but this clearly won't be a car for the masses. The company also won't discuss charge times for the bigger packs, whether range claims are theoretical or based on actual tests, the car's state of development, or what makes the batteries so good.

"As we are still more than two years away from the start of production, we are not releasing extremely specific technical details about the Model S at this time," spokesperson Rachel Konrad wrote in an email.

So it's more wait and see.

In any case, Konrad argues, range anxiety is overblown.

"With a gas guzzler, most people tend to wait until the car is almost on `E' before they fill it up." Then, "they have to take a detour to a special place (a gas station) and feed the beast an entire tank of gas.

With an electric car, "you do all of your daily driving ... and you come home at the end of the day or evening. In a five-second manoeuvre from the warmth and comfort of your own garage, you plug in your car and voilà, by the morning you have a full charge. It's a similar charging pattern for your cellphone. You are really only `topping off' the charge every night."

Will behaviour change? Do we all have a cozy garage? Add another layer of uncertainty.

pgorrie@sympatico.ca

Toronto Star