What happens when an electric car (EV) catches fire?

High-profile EV fires excite the naysayers who forget that internal combustion engine vehicles are up to 20 times more likely to catch fire.

Electric car fires can pose challenges for firefighters and can be more difficult to extinguish compared to traditional vehicle fires for several reasons:

1. Battery Chemistry: Electric vehicles use lithium-ion batteries, which can contain a large amount of energy in a compact space. When these batteries catch fire, they can release a significant amount of energy, making the fire more intense and harder to control.
2. Heat Release: Lithium-ion batteries can release heat rapidly, and the fire generated can be intense. Traditional firefighting methods, such as water, may not be as effective in cooling and suppressing the fire in the case of lithium-ion batteries.
3. Re-Ignition Risk: Even if the initial fire is successfully extinguished, there is a risk of re-ignition. The cells within the battery can continue to release heat, potentially causing a reignition of the fire.
4. Toxic Gas Emissions: When lithium-ion batteries burn, they can release toxic gases, such as hydrogen fluoride and other hazardous substances. Firefighters need to be cautious about exposure to these gases, which can add complexity to the firefighting process.
5. Unique Fire Characteristics: Electric vehicle fires can exhibit unique fire behavior. For example, they may involve the release of highly flammable electrolyte materials from the battery, creating additional challenges for firefighters.
6. Limited Water Effectiveness: Traditional water-based firefighting methods may not be as effective because water can conduct electricity. Using water on an electric vehicle fire may lead to electrical shock hazards for firefighters and may not effectively cool the battery.
7. Specialized Training: Fighting electric vehicle fires requires specialised training for firefighters. They need to be familiar with the specific hazards and challenges associated with lithium-ion batteries to respond effectively.

As electric vehicle technology continues to evolve, efforts are being made to improve the safety of batteries and develop more effective firefighting strategies. Fire departments are adapting their training programs and equipment to address the unique challenges posed by electric vehicle fires. Additionally, manufacturers are implementing safety features in electric vehicles to reduce the risk of fires and enhance overall safety.

Generally, with an EV fire, you get more warning and it develops more slowly. It can only develop in the batteries – there’s no flammable liquid to leak out and become a fire risk in a similar way to petrol or diesel.

How do you fight a lithium-ion battery fire in an electric vehicle?

1. Isolation and Evacuation:
   • Establish a safe perimeter around the fire to prevent the spread of flames and protect bystanders.
   • Evacuate people from the immediate vicinity to ensure their safety.
2. Identify the Battery Type:
   • Determine the type and configuration of the lithium-ion battery involved, as different chemistries and designs may require different firefighting approaches.
3. Use Class D Fire Extinguishers:
   • Class D fire extinguishers, specifically designed for metal fires, can be effective in suppressing lithium-ion battery fires. These extinguishers typically contain a dry powder, such as lithium chloride, that helps smother the fire.
4. Avoid Water:
   • As mentioned above, do not use water to extinguish a lithium-ion battery fire. Water can conduct electricity and may lead to electrical shock hazards. Additionally, water may not effectively cool the battery and could exacerbate the situation.
5. Cooling the Battery:
   • Apply cooling techniques to reduce the temperature of the battery and minimize the risk of re-ignition. This may involve using specialized cooling agents or equipment designed for battery fires.
6. Use Thermal Imaging:
   • Thermal imaging cameras can be used to identify hot spots and monitor the temperature of the battery. This information helps firefighters assess the effectiveness of cooling measures.
7. Apply a Battery Fire Blanket:
   • Some firefighting agencies use specialized fire blankets designed to smother and cool lithium-ion battery fires. These blankets are made of fire-resistant materials and can help contain the fire.
8. Wait for Complete Extinguishment:
   • Even after the visible flames are suppressed, it is crucial to monitor the battery for an extended period to ensure complete extinguishment and prevent re-ignition.
9. Ventilate the Area:
   • Once the fire is under control, ensure proper ventilation to disperse any lingering gases or fumes.

Other risks

Electric cars use a relatively small number of batteries compared to much larger electric vehicles such as HGVs and mining equipment. The much larger batteries of those machines carry a lot of potential energy to fuel a fire.

In an HGV, the batteries can sit in the chassis under the kingpin. A driver driving an HGV towing a trailer of dangerous goods may not have enough time to disconnect the trailer and move the tractor unit to a safe place where the fire doesn’t threaten the hazardous materials.