In an uncommon move, the National Highway Traffic Safety Administration (NHTSA) issued a statement announcing the opening of a formal safety defect investigation to assess the risk of fire in Chevy Volts that have been involved in a serious crash.
This past May, NHTSA crashed a Chevy Volt in an NCAP test designed to measure the vehicle's ability to protect occupants from injury in a side collision. During that test, the vehicle's battery was damaged and the coolant line was ruptured. When a fire involving the test vehicle occurred more than three weeks after it was crashed, the agency concluded that the damage to the vehicle's lithium-ion battery during the crash test led to the fire. Since that fire incident, NHTSA has taken a number of steps to gather additional information about the potential for fire in electric vehicles involved in a crash, including working with the Department of Energy and the Department of Defense--in close coordination with experts from General Motors--to complete rigorous tests of the Volt's lithium-ion batteries.
In an effort to recreate the May test, NHTSA conducted three tests last week 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 the November 18 fire incident is continuing this week. Yesterday, the battery pack that was tested on November 17 and that had been continually monitored since the test caught fire at the testing facility. The agency is currently working with DOE, DOD, and GM to assess the cause and implications of yesterday's fire. In each of the battery tests conducted in the past two weeks, the Volt's battery was impacted and rotated to simulate a real-world, side-impact collision into a narrow object such as a tree or a pole followed by a rollover.
NHTSA is not aware of any roadway crashes that have resulted in battery-related fires in Chevy Volts or other vehicles powered by lithium-ion batteries. However, the agency is concerned that damage to the Volt's batteries as part of three tests that are explicitly designed to replicate real-world crash scenarios have resulted in fire. NHTSA is therefore opening a safety defect investigation of Chevy Volts, which could experience a battery-related fire following a crash. Chevy Volt owners whose vehicles have not been in a serious crash do not have reason for concern.
While it is too soon to tell whether the investigation will lead to a recall of any vehicles or parts, if NHTSA identifies an unreasonable risk to safety, the agency will take immediate action to notify consumers and ensure that GM communicates with current vehicle owners.