Updated: Apr 25
We established a global EV battery fire database to find out
If you're a regular reader of automotive news, you'd be forgiven for thinking all electric vehicles are fire prone, at risk of exploding into flames at any moment.
But, in news that will annoy some, Twitter guru Elon Musk is correct. It's unlikely that your EV battery will be involved in fire, with far less chance of it occurring than with traditionally fuelled vehicles.
Our research found there's a 0.0012% chance your passenger electric vehicle battery will catch fire, which is a much smaller risk than we expected to find. Reliable sources regarding global internal combustion engine vehicle fires are difficult to verify, but overall many sources quote a 0.1% chance of your petrol or diesel car igniting.
Here's the (downloadable) breakdown:
When EV battery fires do occur, what does the data tell us?
When placed side-by-side with internal combustion engine vehicles, EVs really do present a completely new collection & combination of risks & challenges that are not yet understood.
The fact that EV battery fires are rare means any opportunity to learn more about fire & vapour cloud behaviour, suppression techniques & reignition events is important. That's why our database is broken down into as much granular detail as possible, & why we always attempt to gather first hand accounts from attending fire agencies.
Cause: primarily unknown, either due to lack of detail in reporting, that a cause was not established or is still under investigation. Not surprisingly, collision was the most common cause of thermal runaway, leading to battery fire.
Location: Electric vehicle battery fires happen almost equally parked outside, parked in an enclosed space or while driving.
Ignition vs explosion: EV battery fires primarily ignite, with almost 90% of incidents indicating jet-like flames from underneath the vehicle (burning gases escaping under pressure). In 10% of incidents, a vapour cloud explosion was described or shown in security or private footage.
Vapour cloud explosion (VCE): Of VCE incidents, almost 65% occurred in an enclosed space, such as a private home garage or underground multi-level carparks. There has been one EV fire within a tunnel, but this is not yet included in our data as we're still verifying whether it involved the traction battery.
EV charging connection: The prevalence of EV battery fires while connected to energised charging was the original focus of our project, so it was not a surprise to discover that over a third happen at or near EV charging.
Electrocution: One of the most surprising findings was that electrocution is a lower risk than previously thought. Electrocution remains a significant risk to emergency responders, however due to safety systems that isolate the high voltage battery if the airbags go off, for example, this risk may be able to be adequately mitigated through testing, training & PPC.
Reignition: A partially burnt EV battery pack that has been suppressed may go into thermal runaway hours, days or even weeks after the initial incident. This occurred in 10% of the incidents we researched & highlights the need for secondary responders such as tow truck drivers, storage yards & automotive workers to be trained to recognise thermal runaway is developing.
What does our EV fire data exclude?
We have not counted electric vehicles involved in fire that did not include the high voltage traction battery. Other studies, including the AutoInsuranceEZ overview, include all types of EV fires, & therefore may quote a higher risk percentage.
Around 4% of the incidents we studied involved an EV battery being involved in fire, however the fire originated from outside the vehicle; ie. the garage structure caught fire first. We have included these in our database as an EV battery fire was still managed by emergency responders.
What's next for our EV battery fire research?
While speaking with international & Australian fire-fighters, fire agencies & battery experts, it become clear that there are significant & numerous knowledge gaps in enhancing safety for emergency responders who'll be dealing with these incidents as EVs become common.
Throughout 2022, we're aiming to work with Defence & fire agencies to test our theories around how EV charging units behave if a burning EV is connected & developing videos & tools to help emergency & secondary responders get to grips with electric vehicle identification & technology.
We'll also be at the forefront of new product development, working to understand & test EV battery fire innovation as it comes to market.
Most importantly, we'll be continuing to develop our world-leading research database, expanding the scope to include commercial electric vehicles for the wider benefit of the global transport community.
How to stay in touch
If you're an emergency responder or driver that's experienced an EV traction battery fire & can share the details for our database, we'd appreciate an email from you. You can also download our free information presentation pack with overview information for your emergency brigade or group.
If you're interested in following what we do, we'll be sending occasional newsletters, so please join the mailing list to get it first. But, if you're more of a socials person, find us on Facebook, Instagram, LinkedIn & YouTube.