In an effort to recreate the May test, NHTSA conducted three additional tests on the Volt's lithium-ion battery packs that intentionally damaged the battery compartment and ruptured the vehicle's coolant line. Following a test on November 16 that did not result in a fire, a temporary increase in temperature was recorded in a test on November 17. During the test conducted on November 18 using similar protocols, the battery pack was rotated within hours after it was impacted and began to smoke and emit sparks shortly after rotation to 180 degrees. NHTSA's forensic analysis of that incident incident is continuing. On November 24, the battery pack that was tested on November 17 caught fire at the testing facility.
The agency said it is currently working with the Department of Energy, the Department of Defense, and GM to assess the cause and implications of the Thanksgiving Day fire.
In the meantime, the agency is continuing to work with all vehicle manufacturers to ensure they have appropriate post-crash protocols; asking automakers who currently have electric vehicles on the market or plan to introduce electric vehicles in the near future to provide guidance for discharging and handling their batteries along with any information they have for managing fire risks; and engaging the Department of Energy and the National Fire Protection Association to help inform the emergency response community of the potential for post-crash fires in electric vehicles.
NHTSA's current guidance for responding to electric vehicles that have been in a crash remains the same. The agency continues to urge tow trucks and repair facilities to ensure the damaged vehicle is kept in an open and not instead of inside a garage or other enclosed building.
Rather than attempt to discharge a propulsion battery the facility manager should contact experts at the vehicle's manufacturer on that subject.