Incidents involving motor vehicles catching fire and the subsequent consequences are well documented and in recent times regretfully have become a common sight on UK roads.
Causes can include overheating components, wearing components and electrical faults providing a source of ignition in an atmosphere or area already suffering from an ingress of fuel, lubricants or combustible materials.
The risk of an electric vehicle (EV) catching fire has been cited as potentially greater than those occurring in ICE (Internal Combustion engine) equipped vehicles.*
This potentially increased risk is associated with the electrical components on the vehicle, some of them are operating at high voltages and a new phenomenon whereby EV’s are catching fire, without warning, despite vehicles being switched off and electrically isolated.
Our previous insight paper raised awareness of the potential risks associated with thermal runaway, whereby in an EV, vehicle propulsion batteries fail internally, causing short-circuiting within the battery cells in a flammable environment and as combustion occurs within the battery, new flammable products including oxygen are produced, thus further fuelling the fire.
Physical damage to battery packs, unknown to the driver but causing internal issues to the battery pack itself, can result in combustion later on, possibly sometime after vehicle has been parked.
This presents challenges to our emergency services as although the ensuing fires can be controlled utilising normal procedures, there is the possibility of the battery itself re-igniting after a short period. To manage this, the emergency services utilise thermal imaging equipment to monitor hot spots on the vehicle involved, however this requires them to remain present at the scene for longer periods to ensure the battery packs are cooled using water rather than other extinguishants normally associated with fighting a vehicle fire.
Some parking areas may contain fire extinguishing systems that are not be suitable to control the type of fire seen with an EV where cooling the battery pack is key to control thermal runaway.
A well-known car manufacturer has recently experienced four instances of a fire in a particular model, believed to be caused by faults in the vehicle batteries. This has initiated a mass recall of vehicles.
The most significant areas of concern are where vehicles are parked, stored, transported or undergoing recharging in confined environments such as:
In many cases the length of charging cable provided by the vehicle manufactures and the siting of EV charge points particularly as we see more and more domestic installations can compromise the ideal situation of placing an electric vehicle away from other vehicles and premises.
Technical developments are moving fast – we have had several decades to manage the risks presented by vehicles with ICE and manufacturers will seek to continue to mitigate this risk in the design of their product, but ultimately, they cannot control the way a vehicle is used or maintained.
The specialist practises of Transport Risk Management and Property Risk Engineering continue to monitor, advise and raise awareness of emerging risks with insight and detailed surveys.
Please contact us to discuss the services we can provide.
*https://www.technologyreview.com/2013/11/26/175306/are-electric-vehicles-a-fire-hazard/