Electric vehicles are less likely to catch fire but harder to put out
Electric vehicles are less likely to catch fire but harder to put out, study says.
Electric vehicles are expected to help improve air quality, reduce fuel costs and become a new revenue driver for automakers.
But with the transition to vehicle electrification comes new challenges: Cars with lithium-ion batteries can be especially dangerous when they catch fire.
The good news is that EV fires don’t happen very often. Emma Sutcliffe, program director at EV FireSafe in Melbourne, Australia, said researchers would need more data to finalize fire rates, but preliminary research suggests that fires in pure electric vehicles are rare.
Research by another company, AutoInsurance EZ, shows that battery electric vehicles have only a 0.03 percent chance of catching fire, compared with 1.5 percent for combustion engine vehicles.
According to their research, a hybrid vehicle with both a high-voltage battery and an internal combustion engine had a 3.4 percent chance of a vehicle fire.
However, Sutcliffe said that when fires do occur, EVs with lithium-ion batteries burn faster, get hotter, and require more water to be extinguished.
Hours or even days after the fire was initially contained, the battery could reignite and put repair shops and other establishments at risk.
Chas McGarvey, chief fire officer of the Lower Merion Fire Department in Pennsylvania, said his department was challenged with a Tesla Model S Plaid fire in 2021 that was burning very hot , and even melted the road below.
“A lot of times, firefighters and fire agencies just hope they can find a solution,” Sutcliffe said.
With so many new models hitting the road, Pennsylvania Fire Chief McGarvey said: “We’re still trying to understand. All these things, but they change almost every day!”
Eric Wachsman, director of the Maryland Energy Institute, said the characteristics of lithium-ion batteries that are powerful enough to drive passenger cars can also make them prone to fire, especially if the cells inside the battery are damaged or when there are defects.
Lithium-ion batteries have two electrodes in close proximity, which increases the potential for short circuits, Waxman said, and the batteries are filled with a flammable liquid electrolyte. “This flammable liquid could go into what’s called a thermal runaway and start to boil, causing a fire,” he said.
Electric vehicles include battery management systems to keep the internal high-voltage battery at a safe operating temperature, and these systems control the rate at which the battery charges and discharges.
Improvements to them, along with improvements to the batteries themselves, will make electric vehicles safer.
Tesla recently announced that it will switch from lithium-ion batteries to lithium iron phosphate (LFP) batteries. Other major automakers, including Ford and Volkswagen, are also replacing nickel or cobalt used in some electric vehicles with LFP.
“These batteries are generally considered to be much safer,” said Paul Christensen, professor of electrochemistry at Newcastle University.
Ultimately, he believes, fully electric cars will be safer than the petrol or diesel cars they replace.
Christensen said: “We have spent a long time fully understanding the risks and hazards of gasoline and diesel vehicles.
Now, we must learn faster how to meet the challenges posed by electric vehicles. We can do it.”