DETROIT (AP) — The U.S. government's auto safety watchdog has closed an investigation into Tesla electric car battery fires after the company said it would install more shields beneath the cars.
The shields, an aluminum bar, a titanium plate and another piece of aluminum, will supplement a quarter-inch-thick aluminum plate now on the Model S, the only model that Tesla now sells. They're designed to stop road debris from penetrating the car's battery pack.
The National Highway Traffic Safety Administration began investigating the Model S last year after two battery fires that were caused by road debris. In each case, one near Nashville, Tennessee, and another near Seattle, debris punctured the aluminum shield and the battery, touching off fires. Drivers were able to safely pull off the road and escape without injury, but the cars were destroyed.
Tesla CEO Elon Musk said in a statement Friday that the company will retrofit Model S cars sold in the U.S. with the new shields, at no cost to owners. At the end of February, Tesla had sold about 22,000 of the cars in the U.S., according to Autodata Corp. The additional shields will be provided upon owner request or as part of normally scheduled service, the statement said.