04.5 EV fires & charging research
The focus of our research is EV battery fires that occur while connected to charging
Throughout our research, the number of EV battery fires that occur while connected to EV charging sits in the range of 18% to 30%. These include EVs that went into thermal runaway while connected to AC or DC EV charging, or within an hour of being disconnected from AC or DC EV charging.
This has been further benchmarked against national data from countries that track & publish EV fires, many of which report similar percentages. We will continue to refine this data as emergency response and reporting matures.
In all discussions regarding charging-connected EV battery fires, it should be noted that electric vehicles, by definition, spend significant periods of time connected to energised charging, so these incidents should not be considered unusual.
However, the number of EV fire incidents while connected to energised charging highlights the need to consider emergency response at charging hubs; on-site hydrants, fire appliance access, pre-incident planning & water run-off.
In 2023, EV FireSafe was commissioned by the Australian Building Code Board to explore EV fire safety at charging, a report that led to the development of the ABCB's Advisory Notice Electric Vehicles in Buildings; click image to download.
Can EV charging cause a battery fire?
It is a common misconception that the presence of EV charging automatically increases the risk of an EV battery fire. This has been particularly prevalent on social media, particularly amongst those who make money via 'clickbait'.
Put simply, in normally operating road-registered EVs, it is electrically impossible for the battery to be overcharged so it catches fire while using an electrically compliant unit that has been installed to standard by a qualified person.
So, why do charging-connected battery fires occur?
As our research & knowledge in the EV fire space progresses, we are able to more often determine causes of charging-connected EV battery fires.
Currently, we believe the majority of charging-connected EV battery fires occur due to the EV having been previously damaged, then connected to charging.
Through our research, we have determined the primary causes of damage leading to an EV battery fire are;
Collision / road debris:
Road traffic collision where the battery pack has been significantly damaged, or where the EV has run over road debris causing significant damage to the pack.
Submersion:
Where an EV is submerged in flood water for an extended period (usually hours to days), particularly salty / coastal flood water. See How many EVs have caught fire after Hurricane Ian for more details on why this occurs.
Recall:
Where an EV has been recalled by the manufacturer due to a fault that could lead to a lithium-ion battery fire.
External fire:
An EV is exposed to a building or bush fire that burns under the battery pack, or spreads to the vehicle body & onto the battery pack.
35 connected to energised charging
5 within one hour of charging
1 due to extension cord
1 improper cable
1 building electrical fault
16 due to cell defect during manufacturing
16 unknown cause
