Electric car batteries can catch fire days after an accident

By Aleanna Siacon / Detroit Free Press

When a Tesla Model S crashed into a palm tree and caught ablaze just outside of Fort Lauderdale, Florida, last February, firefighters struggled to extinguish the flames and the car reportedly re-ignited multiple times.

Similar stories of electric vehicles bursting into stubborn flames have cropped up from Florida and California to Austria and China.

While electric cars are transforming commuting, the new technology also is turning into a safety challenge for first responders.

According to researchers, lithium-ion batteries are prone to a phenomenon known as thermal runaway — a process where battery temperatures sharply increase to the point where they catch on fire or explode.

Rochester Hills, Michigan, Fire Chief Sean Canto said the National Fire Protection Association (NFPA) has put together alternative fuel vehicle safety training for fire departments, which is considered “best practices” within the industry.

Those include:

• Locating the car’s power source, and breaching the boxes/casing
• Using copious amounts of water to continuously cool the car battery, in addition to conventional fire suppression tools and tactics (like firefighting foam)
• Keeping the car away from structures after the incident, because of the danger of re-ignition

Still, fighting electric vehicle car fires can be tricky.

Auburn Hills Assistant Chief Antonio Macias said a big part of responding to roadway accidents is recognizing the vehicle and knowing where to access and how to cut the car’s power source.

For example, Macias said, electric car batteries are often placed in “inconspicuous places,” which can be difficult for first responders to access. He added that firefighting foam isn’t effective unless it’s able to penetrate the car battery’s case.

Royal Oak Fire Chief David Cummins said first responders use mobile apps that can help them quickly learn how to locate and properly disable a car’s power sources. Among them, he said, is the NFPA/Moditech AFV EFG (Alternative Fuel Vehicle Emergency Field Guide).

Alfie Green, chief of training for the Detroit Fire Department, said mobile apps are a huge help, especially because the color of the wiring in cars hasn’t been standardized.

Green said the city focuses on training to keep firefighters up to date on the latest “idiosyncrasies” with various car models.

The biggest tool in fighting electric vehicle fires is the most basic: water.

But it takes lots of it — “copious amounts,” Macias said.

The response is needed, he said, because the batteries need to be cooled to keep them from re-igniting.

“You don’t want to mix water and batteries, but unfortunately this is where you got to go,” Macias said.

Cummins said that while the hazards involved in responding to an electric vehicle aren’t dissimilar to an ordinary car fire, these batteries pose a unique challenge.

“The one marked difference would be that if the batteries are involved, some metals in the batteries may react violently with water,” Cummins said.

What’s important, Wells said, is to fight any car fires from a safe distance and to “take extreme caution” with any electric hazards.

As technology evolves, fire officials said, it’s crucial that departments keep a dialogue with automakers regarding vehicle safety.

In Auburn Hills, Macias said his department received product-specific emergency response guidelines — specifically, PowerPoints about self-driving vehicles.

“The more that we can work together and give them ideas about how we might be able to mitigate the incident without causing them more cost on production … the safer we will be,” Macias said.