Lithium-ion batteries have been hitting the headlines for all the wrong reasons. Fire authorities report seeing over 10,000 fires caused by these batteries each year across Australia.
But what does this mean for electric vehicles, and the people who repair them? NCR looks at the risks and what can be done about them.
With sales more than doubling in the last year, EVs are slowly becoming more popular in Australia. But even with their rising popularity, doubts remain about their safety.
Lithium-ion batteries are small, rechargeable batteries that can store large amounts of energy in a small space. This battery can also be found in households, in items such as phones, laptops, and vapes, but also in numerous battery powered tools in the workshop. A normal EV battery is powered by hundreds of these in a bank.
While the news about fires have heightened safety concerns, authorities agree it is training and knowledge about the risks associated with lithium-ion batteries that can best lower the risks.
Handle with care
One area of concern that is causing many of the fires, more often with the general use of smaller lithium-ion batteries, is incorrect disposal or improper care. All batteries are susceptible to exothermic chain reactions. When scores of these reactions occur, it is called ‘thermal runaways’. This is a chemical reaction causing a sharp increase in the internal battery temperature. When a battery generates more heat than it can dissipate, it results in a fire.
Chemical Engineering Lecturer at Edith Cowan University Dr Muhammad Rizwan Azhar explains the science behind these reactions.
“To create any fire, you need three things; fuel, oxygen, and a high temperature,” he says. “Fuel exists in the plastics of a battery, and oxygen is also preexisting in every battery, meaning when the temperature of the battery rises, all three components of a fire are present, instantly igniting the battery. This is why the importance of temperature regulation must be prevalent and prominent.”
The reasons for the fires can be traced to multiple factors including, but not limited to improper charging of the battery, manufacturing defects, or even physical damage. Dr Azhar believes mechanical compromise as an external factor is the main reason for the fires. When the battery is cracked, the physical and chemical properties exude a larger outward reaction, which if it isn’t a fire, can result in one quickly. Even though they can be dangerous, the chances of one of these fires occurring in an EV are very rare.
Low chances
EV FireSafe is an organisation endorsed by the Australian Department of Defence, who research EV battery fires and emergency responses. They have established the only detailed incident database for fires in EVs. Their database shows 18 percent of fires occur when vehicles were charging and two percent were within an hour of disconnecting from the charger. EV FireSafe found from 2010 to June 2023, only 4 fires happened to EVs in Australia. Globally, there were approximately 30 million EVs on the road, and 393 fires occurred.
Safety preparation
Australian Automotive Aftermarket Association (AAAA) Marketing Coordinator Jos Roder says now that there is more demand for EVs in the market, workplaces need to be further trained on how to work with them.
“A lot of workers have been servicing hybrid cars for a while, so the concept isn’t totally new, but it’s just another level and a larger number of cars,” he says.
The AAAA has been a strong advocate that EV training and preparation for repairers, supported by governments, should be a crucial part of the New Vehicle Efficiency System. This will ensure not only that workshops and repairers are safe but that the repair experience for owners will improve.
They suggest that all repairers who will be working on EVs undertake basic safety and training courses on depowering, such as the AURETH101, and safely maintaining those vehicles when handling lithium-ion batteries.
Working on EVs can pose additional risks to repairers, with hazards including stored electrical energy, and battery electrolytes. SafeWork NSW say repairers have a chance of receiving electric shock if they do not take safety precautions when working on an EV, so depowering them before beginning work on their engines or bodies is critical. Safety steps include using the correct PPE and depowering the EV correctly.
Depowering, or disabling an EV is the process of isolating and disconnecting the battery from the vehicle. This is done to ensure the components of the battery cannot be energised, and then repairers have a safe platform to work on the EV without the chance of electric shock. It notes EVs can also generate electricity when the wheels rotate, so electric shock could be caused by physically pushing the vehicle in the workshop.
Experts say repairers should also get to know any model of vehicle well, and familiarise themselves with all its safety features, thermal management systems, and any sensors that could potentially alert them to a problem.
One crucial tip is to remain cautious about charging the vehicle and not let the vehicle overcharge, because this can significantly increase the risk of it overheating, which is the first step of combustion reactions.
Leading industry-trainer I-CAR Australia also highly recommends courses for general technicians in the automotive repair industry to get better acquainted with depowering and working safely on EVs, including damage analysis and general handling of the parts.
I-CAR Australia recommends damaged EVs are isolated 15 metres, if possible, away from all other vehicles, until they can be assessed. This could prevent potential fire spread and ensures the battery is well ventilated to eliminate any hazardous gases if there is any damage. Ideally, this monitoring would take place for the first 48-hour period following an accident until assessment. Batteries should also be kept out of the weather to protect them from rain and moisture.
In case of emergency
These precautions bring us back to the risk of fire, which however rare, is still worth taking precautions over for any workshop working on EVs.
“These fires are not like normal fires,” Dr Azhar says.
“There is research being undertaken to find the best way to stop these fires, but at this point, there are no specific techniques on putting out the flames apart from adding water, saline water being the best option.”
Experts stress that plenty of water is needed, because using a minimal amount will further fuel the fire.
Azhar says batteries have large chemical reactions when coming into contact with water, meaning the water could potentially fuel the fire and cause it to intensify, instead of shutting it down. This is because of two things. One being the reaction between water and lithium, which produces flammable hydrogen gas, and the second being that water conducts electricity, which means spraying it on a battery powering an electric vehicle can lead to short-circuits or electric shocks.
“It is important to be aware that putting water on the fire will not stop it, only suppress it to ensure that it is not expanding. Keeping the fire burning, at as low a flame as possible is the best and safest way to regulate the fire.”
Other forms of fire suppression include Class D fire extinguishers, or dry chemical fire extinguishers which contain sodium chloride powder that combats the fire by melting to form an oxygen-excluding crust over the fire, not allowing it to grow. After the fire is out, it is common to need to deal with the toxic fumes it leaves behind. The fire releases a combination of smoke, carbon monoxide, hydrogen fluoride, and hydrogen chloride. All these gases can be hazardous to health when inhaled in significant quantities.
EV FireSafe offers free training resources on their websites (section 05.6) for education on EVs.
More information on courses is available through I-CAR Australia, and the automotive trade organisations (MTA’s) in each state, and nationwide (MTAA).