As we transition from internal combustion engine to full-electric cars, a common concern for most would be the infrastructure support, i.e., number of charging stations available. But there is another area of concern – EVs may catch fire days after a crash and take more days to be fully extinguished.
According to the Confederation of Fire Protection Associations Europe (CFPA-Europe), the batteries in electric and hybrid cars present numerous challenges from the emergency services’ perspective.
Individual cells in lithium-ion batteries can be damaged in an accident, causing a build-up of heat which then spreads from cell-to-cell. This event is called thermal runaway. It is a chain reaction that can be rather difficult to stop once started.
In China, it was reported that the BYD Han caught fire after being parked for 48 hours since its crash test. Following that, BYD released a statement suggesting that a coolant leak may have caused the fire. But that, too, raised suspicions of Han owners in China. The real cause of the fire is still currently unknown.
In the US, there was a highly publicised case in which the same fire department was called in twice to put out fire on the same Chevy Bolt. At their second attempt, the fire department could only douse the car continuously, but it kept smoldering for 4 hours.
General Motors (GM) has urged owners of the Chevrolet Bolt to park at least 50 feet away from other vehicles to mitigate the risk of spreading potential fire. The company has recalled all of the Chevy Bolt sold in the US due to the risk of spontaneous combustion.
During battery fires, toxic gases are released. Researches have shown that more than 100 toxic gases are produced such as hydrogen fluoride when combusted. It is said that even small doses of it can result in water in the lungs.
These mean that the fire brigade needs to take extra precaution by wearing breathing apparatus when putting out EV fires.
No sure-fire way (ironic pun intended) of putting out battery flame, other than dunking it into a tank of water.
A solution to battery fires
Michael Kim Andersen, Deputy Director of Emergency Services in Copenhagen, said, “Batteries are difficult to extinguish, and they can burst into flames again several hours later – in some cases, right up to a week later.
“We can’t close roads and motorways for several hours, so if it isn’t possible for us to extinguish the fire in the battery, we may have to remove the car. That’s why we have developed a container for that very purpose.”
EVs cannot be placed amongst other cars in a workshop right after an accident due the risk of spreading fire. Instead, it can be placed in the container until the risk has subsided.
“A fire in an electric car battery is a chemical fire and does not require oxygen. Therefore, inert gas has no effect on the battery but is intended for the other parts of the car. Indeed, the development of heat from the battery can potentially cause the cabin to burst into flames.
“And since it’s a confined space – at least until the windows burst – the water can’t get in there. Therefore, inert gas is required to smother the flames,” explains Michael Kim Andersen.
As it is, to extinguish an EV/HEV fire uses a lot of resources which can quickly become an issue as the world turns to EVs. That being said, this isn’t intended to discourage consumers from EVs. It’s just something we need to keep in mind going forwards, in the hope for a more efficient solution in the future.
The quest for automotive knowledge began as soon as the earliest memories. Various sources information, even questionable ones, have been explored including video games, television, magazines, or even internet forums. Still stuck in that rabbit hole.
