EV fires are hard to fight. Are you prepared?
The global EV sales are growing rapidly. The forecast for 2040 is 85% of all cars sold in the US will be electric.
A study from National Transportation Safety Board (NTSB) found that half of all U.S. fire departments are not prepared to handle fire in electric vehicles.
This guide will give you a better understanding of the challenges with EV fires. Why traditional methods are not working, and the best ways to handle fire in electric vehicles.
01The numbers
Large car manufacturers are phasing out their production of combustion cars by the year 2025. More than half of US car sales will be electric by 2030, according to a report from BloombergNEF in 2021.
Get the facts right
Do EVs catch fire more often than fossil fueled cars?

The answer is no. Based on research by AutoinsuranceEZ, it is five times more likely that a fossil-fueled vehicle will catch fire than an electric vehicle. Hybrid cars with both a high voltage battery and an internal combustion engine have a 3.4% likelihood of vehicle fires according to the same study.

However, when fires do happen, electric vehicles with lithium-ion batteries burn hotter and faster. And the batteries can re-ignite hours or even days after the fire is initially controlled.

02The challenge
There is no simple solution or tool to extinguish EV fires. Traditional methods are just not working. Why do lithium batteries require a whole new approach?
Thermal runaway
The challenge starts within the lithium-ion battery

Thermal runaway, or thermal propagation, begins when the heat generated within a lithium-ion battery exceeds the amount of heat that is dissipated to its surroundings. This can happen due to overcharging, physical damage to the battery cell, short circuits, or because of high temperatures.

Factors
How do lithium batteries ignite?

Lithium batteries are extremely sensitive to high temperatures and inherently flammable. They are known to reignite hours, days, or even weeks after the initial burst – and can do so several times. 

Which factors can start a fire in a lithium-ion battery?

Overcharging
Physical damage
Short circuit
High temperatures
Water
Why traditional methods are not working?

It is an unfortunate myth that thermal propagation can be controlled with water. The only way to extinguish a fire in a lithium battery is to cool down the battery.

One example is using water to cool down the batteries while lifting the burning vehicle to reach the area where the batteries are located. This method requires a lot of water and is time-consuming. 

This method usually has a limited effect due to the construction of EVs with several insulating layers of metal and air.

Another major problem with using water is the contamination of air and groundwater when thousands of liters of water seep into the ground.

Pouring water on the fire or an already overheated battery can actually make the situation worse, and cause short circuits in several places in the batteries.

03The batteries
There are three main battery types used in electric vehicles; cylindrical, prismatic and pouch batteries.
The three main battery types used in electric vehicles:
Cylindrical
This is the most common type of battery, and the kind we buy in the store. It can be used in EVs, but it is not very space efficient and therefore provides less energy.
Prismatic
Prismatic batteries are made as cassettes and are packed tighter than cylindrical batteries (about 30%). More and more car manufacturers use this solutions.
Pouch
Pouch cells do not have a rigid enclosure and use a sealed flexible foil as the cell container. This reduces weight and leads to flexible cells that can easily fit the available space of a given product.
The three main battery types used in electric vehicles:
Cylindrical
This is the most common type of battery, and the kind we buy in the store. It can be used in EVs, but it is not very space efficient and therefore provides less energy.
Prismatic
Prismatic batteries are made as cassettes and are packed tighter than cylindrical batteries (about 30%). More and more car manufacturers use this solutions.
Pouch
Pouch cells do not have a rigid enclosure and use a sealed flexible foil as the cell container. This reduces weight and leads to flexible cells that can easily fit the available space of a given product.
What’s next
Are solid state batteries the future?

Solid-state batteries could be a game changer for electric vehicles because they can charge faster and store more energy than lithium-ion batteries. It actually stores 2-2.5 times more energy at the same volume as lithium-ion batteries do.

In addition, solid-state batteries are also lighter, tend to be less flammable and can withstand more physical damage than lithium-ion batteries. Which means more powerful and longer range electric vehicles, or more compact and lighter.

However, solid-state batteries cannot withstand water when damaged, as the lithium metal is an element that naturally catches fire in contact with water! Watch the film below to see how it reacts to water.

04The methods
The only way to extinguish a fire in a lithium battery is to cool down the battery cells directly. The problem is that there is no direct access to the inside of the battery box. So what is the most effective solution to cool the batteries down?
The methods
Let´s take a look at the most used methods for cooling down the battery
Firefighting foam
Extinguisher
Water container
Nozzle
Piercing nozzle
Fire blanket
Do you want to know more about Bridgehill® fire blankets?