DETROIT (AP) – Electric vehicle fires pose safety risks for rescuers and manufacturers’ guidelines on how to deal with them have been inadequate, according to US researchers.
There are also gaps in industry safety standards and fire research on high-voltage lithium-ion batteries, especially in high-speed serious accidents, the National Transportation Safety Board said on Wednesday.
The agency, which has no enforcement powers and can only make recommendations, asked manufacturers to write specific vehicle response guides to fight battery fires and limit chemical thermal leakage and re-ignition. The guidelines should also include information on how to safely store vehicles with damaged lithium-ion batteries.
The recommendations come at a time when automakers are launching several new models of electric vehicles, with many in the industry realizing a tipping point in shifting energy from gasoline to cleaner electricity.
The agency in its Wednesday report also asked firefighters and car towing associations to inform members about fire hazards and how to deal with the remaining energy in the battery after an accident, and how to safely store a vehicle with a damaged battery.
And it is asking the National Highway Traffic Safety Administration to include the availability of an emergency response guide when calculating the safety scores for five-star vehicles.
NHTSA must also build a coalition to research ways to de-energize batteries and reduce the risk of thermal leakage, a chemical reaction that causes uncontrolled increases in battery temperature and pressure.
The NTSB began investigating battery fires following accidents and fires in Lake Forest and Mountain View, California, and Fort. Lauderdale, Florida, in 2017 and 2018. He also investigated an accident-free fire in West Hollywood, California. Three of the batteries rekindled after the fires were extinguished.
All four vehicles were made by Tesla, which is the best-selling electric vehicle manufacturer in the U.S.
“The risks of electric shock and battery reactivation / fire arise from the ‘lost’ energy that remains in a damaged battery,” said the agency.
In the August 2017 fire in Lake Forest, a Tesla Model X battery caught fire after the vehicle pulled off a road and crashed into a high-speed residential garage. Thomas Barth, NTSB engineer and road investigator, said in an agency video that firefighters poured thousands of liters of water on the roof of the vehicle. “They didn’t realize that they had to direct water to the battery compartment under the car to cool the battery and stop the reaction that caused the fire,” he said.
In an 80-page report, the NTSB wrote that a review of the 36 manufacturers’ emergency response guidelines found that everyone had ways to reduce the risk of high voltage shocks, including methods for disconnecting the battery. But none of the guides spoke of limiting the risk of energy stored in batteries, such as procedures to minimize reignition or instructions on where and how to spray water to cool batteries, the agency said.
One way to deal with damaged batteries is to pull them out of the vehicle and dip them in a salt water bath to discharge the energy, the NTSB wrote.
The National Fire Protection Association, which offers training for rescuers and towing companies, said it had already met most of the NTSB recommendations. Andrew Klock, lead manager for emerging issues, says the group offered training on how to extinguish battery fires, then raise vehicles and extinguish batteries with water to limit reignition.
The NFPA has trained about 250,000 rescuers, but there are 1.2 million firefighters across the country, said Klock.
In a statement, NHTSA said last week it started a battery safety initiative to address growing concerns about fires in electric vehicles and battery-powered structures. With the initiative, the agency will analyze data, investigate fires and supervise investigations of electric vehicle accidents, the agency said.
Alliance for Automotive Innovation, a major commercial group at the automaker, said it will review the recommendations and is working with fire brigade associations, NHTSA, Society of Automotive Engineers and others to improve safety.
Messages were left on Wednesday seeking comment from Tesla and the National Fire Protection Association.