Electric cars offer a pathway to cleaner air, lower fuel prices and represent a rapidly growing category of automakers. However, electric vehicles pose a challenge as they can catch on fire.

It’s not often that battery electric vehicle fires occur.

Emma Sutcliffe (project director of EV FireSafe Melbourne), Australia says that although preliminary data indicate that fires from fully-electric vehicles are uncommon, more research is needed in order to conclude the fire rates.

Another firm can conduct research AutoinsuranceEZAccording to the study, battery electric vehicles only have a 0.033% chance of starting, as compared with internal combustion engines’ 1.5% probability. Their study shows that hybrid electrics which combine an internal combustion engine and a high-voltage battery have a 3.4% probability of vehicle ignition.

Sutcliffe explains that when there are fires, the electric vehicles powered by lithium ion battery burn faster, require more water and heat, and can take longer to put out. The batteries are capable of igniting hours, or even days, after a fire has been put out, putting at risk salvage yards and repair shops.

CNBC spoke with Chas McGarvey about the Pennsylvania Lower Merion Fire Department’s Chief Fire Officer. He said that one Tesla Model S Plaid Fire his team managed in 2021 had burned so hot it caused a smoldering of the pavement beneath.  

Sutcliffe stated to CNBC that “a lot of time fire fighters or fire agencies just kind of figure out.” McGarvey, the Pennsylvania fire chief, said that there are many models on the market and “we’re still trying to get up to all of this stuff.” It changes nearly every day!

Eric Wachsman (Director of Maryland’s Energy Institute) says that lithium ion battery batteries are powerful enough to drive a passenger van, but they can be vulnerable to ignition, particularly if the battery cells inside them have been damaged or defective.

The electrodes of lithium ion batteries are placed closer together which can increase the likelihood that there will be a short.

“This flammable liquid could get into what’s called a thermal runaway situation where it just starts sort of boiling, and that results in a fire,” he said. 

Electric vehicles include battery management systems to maintain the right operating temperature for high voltage batteries inside, and those systems control how fast batteries charge and discharge. EVs can be made safer by making improvements to these systems as well as to the batteries themselves.

Tesla announced recently that it will switch from lithium-ion batteries to lithium ironphosphate (LFP), battery cells. Ford and VW have also switched to LFPs as a replacement for nickel or cobalt in electric vehicles.

“These are generally believed to be a lot safer,” said Paul Christensen, a professor of electrochemistry at Newcastle University whose research focuses on lithium ion battery fires and safety.

In the end, he thinks fully electric cars have the potential to be more safe than diesel- or gasoline-burning vehicles.

“We’ve had a long time to fully understand the risks and hazards associated with petrol and diesel cars. We’re going to have to learn faster how to deal with the challenges with electric vehicles. But we will.”