Tesla Motors CEO Elon Musk defended the safety of the company’s flagship Model S sedan after a fire involving one of the cars raised questions about its lithium-ion battery pack.
A Model S driven in Kent, Wash., near Seattle, on Oct. 1 struck metal debris on the road. Musk said in a statement Friday on the company’s website that the object appears to be a “curved section” that fell off a semi-trailer. The car’s warning system alerted the driver to pull over and exit the vehicle, after which the fire broke out, he said.
“The geometry of the object caused a powerful lever action as it went under the car, punching upward and impaling the Model S with a peak force on the order of 25 tons,” Musk said. “Had a conventional gasoline car encountered the same object on the highway, the result could have been far worse.”
News of the fire, the first such incident involving a Tesla vehicle, triggered a 10 percent drop in the company’s shares over two days, reflecting concerns that the incident may tarnish the automaker. Tesla, already the world’s biggest seller of premium battery-powered cars, has soared fivefold this year after posting its first quarterly profit, repaying a U.S. government loan nine years early and expanding Model S sales to Europe and Asia.
The Washington State Patrol and local authorities are investigating the incident. A review by U.S. safety inspectors isn’t likely soon because they are among furloughed workers during the U.S. government shutdown.
The collision punctured the battery pack’s aluminum casing, creating a 3-inch hole, Musk said. The fire caused by the impact was in the front battery module, one of 16 in the car, and “was contained to the front section of the car by internal firewalls within the pack,” he said.
The Model S battery casing offers more protection than that of gasoline-powered autos, said Musk, who is also the Palo Alto, Calif.-based company’s biggest shareholder.