Lithium Batteries: Understanding Their Fire Risks and Prevention

One of the most common concerns surrounding electric vehicles (EVs) is the risk of lithium-ion battery fires. While these batteries can indeed catch fire, they do so in a different and often more dangerous manner compared to traditional fuel sources like gasoline or diesel. This article aims to explore the causes of lithium battery fires and provide practical measures to prevent them.

Understanding the Causes of Lithium Battery Fires

The primary cause of lithium battery fires is spontaneous ignition, a process where batteries release lithium metal as a side product during a short circuit or overcharging. This can lead to a local temperature rise, which in turn can propagate a fire. Other contributing factors include manufacturing defects, software or power issues, and physical damage from accidents or faulty charging hardware.

Statistics from various sources indicate that lithium-ion batteries are highly resistant to external ignition. A fire might start from an external source, but the internal chemistry of the battery can lead to an uncontrolled release of energy, causing a spontaneous combustion. This phenomenon can occur at any time, 24/7, and is inherent to the nature of these batteries.

Unprecedented Fire Risks in Electric Vehicles

Unlike traditional vehicles running on gasoline or diesel, EVs can be unoccupied and not always on charge. This unique characteristic makes the risk of fire more significant in enclosed spaces like car parks. Further, EV batteries can reach temperatures of up to 2000 degrees Celsius, which is three times the temperature of gasoline or diesel. These high temperatures make extinguishing EV battery fires extremely challenging.

Addressing Misconceptions

A common misconception is that gas cars (internal combustion vehicles) do not catch fire at the same rate as EVs. In fact, statistics show that hybrid and combustion cars have a higher fire risk compared to EVs. For instance, a recent study by US insurer AutoinsuranceEZ reported that hybrid cars had 3474.5 fires per 100,000 sales, while petrol cars had 1529.9 fires per 100,000 sales. In contrast, EVs had just 25.1 fires per 100,000 sales. Additionally, a school bus EV made national news for catching on fire, and recently, a diesel school bus also caught fire and burned. This highlights that fires can occur in any vehicle, not just EVs.

Prevention Is Key: Practical Measures to Reduce Risks

While spontaneous combustion in lithium batteries is an inherent risk, there are several measures one can take to reduce the risk of a fire starting:

Avoid Fast Charging: Conventional wisdom suggests that fast charging can increase the risk of battery degradation and potential fires. Charging within recommended limits of 20-80% is advisable, especially after intense driving. Allow Batteries to Cool: After driving, allow the batteries to cool down before recharging, particularly if you have engaged in vigorous driving. Avoid Charging Indoors: Do not charge EVs indoors or overnight. Charging should be done in a safe, well-ventilated area. Distance from Property: Park the EV as far away from your property as possible to prevent any potential fire from affecting your home. Look for Expert Guidance: Listen to recommendations from experts like Professor Paul Christenson, a leading physicist and advisor to Nissan, who will provide valuable insights.

Conclusion

While the risk of lithium battery fires in EVs is real, understanding its nature and taking preventive measures can help mitigate this risk. By following the guidelines and being aware of the inherent risks, EV owners can enjoy the benefits of clean, sustainable transportation without the fear of fire hazards.