Fire and Explosions expert, Richard Heath, was invited to contribute to the Keoghs podcast, ‘The Market Affairs Podcast: Lithium Ion Battery Fires’.
Richard joined Head of Market Affairs, Natalie Larnder and Product Liability Partner, Michael Harvey from Keoghs to discuss the complexities surrounding lithium-ion battery fires and their investigations.
Richard explained that a lithium-ion battery is a type of rechargeable battery that uses lithium chemistry as the basis for its rechargeability and added that a “battery” is a collection of two or more individual “cells” that are connected. He stated that lithium-ion batteries have become a widespread use of energy due to their convenience and capacity to store a far greater amount of energy, in a smaller, lighter package, so offering a higher energy density. They are common in all sorts of applications, from electronic portable devices like mobile phones and laptops to e-scooters.
However, the benefits of lithium-ion batteries do not come without risks. They need to be operated within certain voltage, current and temperature limits, otherwise, problems can develop internally causing an uncontrollable release of energy stored inside through a process called thermal runaway. This causes overheating inside the battery and venting of gasses as the parts inside the battery break down.
Richard said that he has seen an increase in fires involving lithium-ion batteries, which is largely due to the greater usage in everyday appliances.
Richard also notes that as the demand for lithium-ion batteries increases, internal construction becomes more intricate given the demand by consumers to have low-cost but effective products. These two factors combined can give rise to a compromise on quality, affecting battery safety. Richard explained that consumers are unaware of the caution required when using lithium-ion batteries. Unlike traditional batteries, lithium-ion batteries are not benign, so improper use contributes to the risk of fire. For example, if consumers buy a second-hand e-scooter, but find that the existing battery needs replacing, they may decide that the original manufacturer’s battery is too expensive, and instead, buy a product online from an unknown and potentially unregulated vendor, which may not meet the required level of quality standards.
Richard said the biggest difference between a normal fire and a lithium-ion battery fire is the rapid development and the severity of the fire from a lithium-ion battery. In a normal house fire, it can take several minutes to develop and spread to adjacent combustible materials. With urban fire services aiming to arrive at a scene within 5-10 minutes of a call, a slowly developing fire means it can be detected in the early stages, allowing the fire service to arrive when the fire is still developing.
However, a failing lithium-ion battery fire is a bit like a firework and represents a much more potent ignition source and can quickly become severe. Products using lithium-ion batteries are often stored inside the home. For example, e-bikes and e-scooters are frequently stored in corridors and hallways, and fires developing rapidly in those locations can quickly spread upstairs and block the means of escape. The severity of these types of fires and the speed at which they spread is also likely to result in more damage. This also makes it more difficult to investigate the cause of the fire since all the evidence is often consumed. A particular difficulty is being able to differentiate between a fire which has spread to a charged lithium-ion battery causing it to fail, and a fire which started because of a lithium-ion battery fault. If a charged lithium-ion battery is attacked by a fire, it will send it into thermal runaway and fail in the same way it would if there had been a fault in the battery itself. The parts inside the battery are mostly of a low melting point, thus making it difficult to tell if the battery was the cause of the fire. Lithium-ion battery fire scenes can be deceptive, as during a failure the battery can eject all the burning parts, causing multiple secondary seats of fires around the room. This gives the fire damage pattern a misleading appearance, making it look multi-seated and started deliberately.
Fires starting in lithium-ion batteries are not necessarily the result of a product fault; they can be a result of user misuse, either accidental or deliberate. Consideration needs to be given to how the product had been used, stored and charged.
Richard rounded up the podcast by explaining how various fire services and electrical safety-first charities are advising consumers on these issues. Advice includes:
- Buy good quality batteries from a reputable brand or trusted source. Cheap batteries and chargers sometimes don’t have the safety features needed to operate and maintain the battery correctly.
- Follow the manufacturer’s instructions on use and charging, to minimise the risk of a problem developing.
- Make sure to use the correct, original charger for the product; using the wrong charger can sometimes expose the battery to the wrong charging voltage which can cause thermal runaway.
Richard joined Hawkins as a Forensic Investigator in 2004 working on behalf of insurers, utilities providers, local authorities and private companies. He specialises in the investigation of fires, explosions and electrical engineering losses, undertaking investigations of fires in industrial and commercial premises. You can listen to the podcast in full here.
