Volvo Questions EV Safety

The Swedish auto maker designed the C30 EV with a high priority on keeping the batteries outside the crumple zones, to prevent a potential fire in the event of a collision.

Tom Murphy, Managing Editor

January 14, 2011

4 Min Read
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North American Int’l Auto Show

DETROIT – Safety is a pillar that supports the Volvo brand around the world, and its foray into electric vehicles will not change that positioning, the Swedish auto maker says.

At this week’s North American International Auto Show, Volvo didn’t unveil a shiny new concept car but instead drew the curtain off a crash-tested C30 EV similar to the production version that arrives in the U.S. later this year for fleet testing.

The front driver’s side of the entry-luxury 4-passenger vehicle was badly mangled by an offset barrier collision at 40 mph (64 km/h), conducted at Volvo Car Corp.’s research and development facility in Gothenburg, Sweden.

C30 EVs also underwent a 51-mph (82-km/h) rear collision, as well as an 18-mph (29-km/h) side impact with a pole. In all cases, batteries and cables were completely intact.

The side collision is of particular concern because EVs with batteries situated directly under the driver and passengers present a unique safety challenge, with their battery cells positioned close to the perimeter of the vehicle, Volvo President and CEO Stefan Jacoby says.

Asked if the point in showing the crashed car is that Volvo has concerns about the safety of EVs, Jacoby says, “yes.”

“I think we have found maybe the most optimal solution for packaging the battery,” he tells journalists. “And with our safety technologies, which we have anyway in our company, we are able – and I don’t want to judge any competitors – to make electric vehicles at least as safe as traditional gasoline or diesel vehicles.”

The C30 EV, like the Chevrolet Volt extended-range EV, has its lithium-ion batteries arrayed in a “T” configuration through the exhaust tunnel running down the center of the vehicle, with additional cells occupying space under the back seat.

View from below shows batteries oriented in center of C30.

Those batteries, supplied by Ener1 Inc., are several inches away from the side of the vehicle, although a Volvo engineer at the display could not be specific.

Volvo does not call out any rivals by name, but the Nissan Leaf has its batteries situated directly beneath the seats. Nissan does not specify the distance from the edge of the 24 kWh battery pack to the vehicle’s side sill.

The Smart EV, arriving now in the U.S., also has its batteries below the seats.

In the event of a severe crash, the Leaf’s high voltage automatically will be disconnected, and there is a manual disconnect inside the vehicle, says Bob Yakushi, Nissan North America Inc.’s director-product safety.

The Leaf’s battery pack is enclosed by a separate structure to help divert crash energy away from the battery pack if a crash occurs, and the side sill structure also absorbs crash energy, Yakushi says.

Volvo designed the C30 EV with a high priority on keeping the batteries outside the crumple zones.

“You don’t want a high level of deformation of the batteries,” Jan Ivarsson, Volvo’s senior manager-safety strategy and requirements, tells Ward’s.

The C30 EV relies on 384 Li-ion battery cells, weighing about 660 lbs. (299 kg), Ivarsson says. The batteries take up some of the space normally occupied by the fuel tank. “It’s very well protected by the chassis system of the car. It is a very rigid structure,” he says.

“I’ve seen some manufacturers’ (vehicles), and it looks like they’ve put batteries in the crumple zones,” Ivarsson says. “In that case, you will have deformation in the batteries, and that is something we don’t really think is a wise approach.”

In a side impact with a pole, Ivarsson says he fears EVs with batteries configured in such a way could release energy. “It could be like you have gas leakage,” he says. “You could have a fire.”

Like the Leaf, the C30 also has a mechanism similar to a circuit breaker that disconnects the battery in the event of a severe crash, within 50 milliseconds.

Nissan says Leaf’s battery safely encased in event of collision.

Nissan’s Yakushi says safety was paramount in the earliest stages of the Leaf’s development, especially protecting the battery pack.

“The Leaf meets and exceeds all safety standards and our own internal safety standards,” he tells Ward’s in an email.

The C30 is in verification now, with additional crash tests still to be done, Ivarsson says. By summer, Volvo hopes the car will be in test fleets in Sweden and elsewhere in Europe, followed shortly after by the U.S.

The goal is to give the C30 EV an operating range of 95 miles (153 km).

Beyond the EV, Jacoby says Volvo will introduce a plug-in hybrid-electric vehicle in Europe in 2012, delivering fuel economy of 120 mpg (2.0 L/100 km). Later, the PHEV will come to the U.S. with a gasoline engine backing up the electric drive.

Now owned by Zhejiang Geely Holding Group Co. Ltd., Volvo sold 374,000 vehicles worldwide in 2010, including 53,948 in the U.S., according to Ward’s data.

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2011

About the Author

Tom Murphy

Managing Editor, Informa/WardsAuto

Tom Murphy test drives cars throughout the year and focuses on powertrain and interior technology. He leads selection of the Wards 10 Best Engines, Wards 10 Best Interiors and Wards 10 Best UX competitions. Tom grills year-round, never leaves home without a guitar pick and aspires to own a Jaguar E-Type someday.

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