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 the Detroit auto show, Volvo drew the curtain off a crash-tested C30 EV similar to the production version that arrives in the U.S. later this year for 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 under the back seat.
Those batteries, supplied by Ener1 Inc., are several inches away from the side of the vehicle. Volvo does not call out any rivals by name, but theLeaf 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 will be disconnected, and there is a manual disconnect inside the vehicle, says Bob Yakushi,North America'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,” 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.”
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.
The C30 EV is in verification now, with more crash tests still to be done.