Flying soon? Know the fire risks from batteries, power banks

Lithium-ion batteries, the stuff that power our everyday items, are often likened to a tank of gasoline or a bullet in a gun. They all contain significant amounts of energy. If released unintentionally, they can lead to a fire or even an explosion.

The biggest upside of lithium batteries: high energy density (high power for less weight). The downside: they can catch fire, or trigger explosions, if damaged or if battery terminals are short-circuited.

When transported by air, they pose a major safety risk. As a result, strict regulations and safety measures are in place, updated each year, to ensure air travel safety.

Here’s what you need to know on the latest International Air Travel Association (IATA) and Federal Aviation Administration (FAA) rules on lithium batteries:

Answer: Yes, but only in carry-on baggage and within a certain power rating.

In general, spare (uninstalled) lithium ion and lithium metal batteries, including power banks and cell phone battery charging cases, must be carried in carry-on baggage only, and NOT in the checked-in luggage.

The Montreal-based International Air Travel Association (IATA) stated in its latest guidance: “Most people are not aware that lithium batteries are dangerous goods that can pose a safety risk if not prepared in accordance with the transport regulations.”

To help with compliance, IATA has developed guidance for shippers, freight forwarders, ground handlers, airlines and passengers – updated for 2024 under the “65th Edition of the IATA Dangerous Goods Regulations (DGR)”. It defines products considered dangerous, classes, exceptions, and prohibitions.

Various airlines strictly prohibit power banks with a capacity of more than 160Wh.

With airline approval, passengers may also carry up to two spare larger lithium ion batteries (101–160 Wh) or lithium metal batteries (2-8 grams).

So is it OK to bring a 20,000-mAH (milliampere hour) power bank on flights? Given that 20,000 mAH equates to less than 100 watt-hours, it is permissible to carry it in cabin luggage.

This is a standard protocol as per FAA: “Devices containing lithium metal batteries or lithium-ion batteries, including – but not limited to – smartphones, tablets, cameras and laptops, should be kept in carry-on baggage. If these devices are packed in checked baggage, they should be turned completely off, protected from accidental activation and packed so they are protected from damage,” the agency added.

Dr Greg Less, a battery chemistry expert and technical director at the University of Michigan Battery Lab, has over a decade of research and development experience in lithium-ion batteries.

“Just like a tank of gasoline or a bullet in a gun, a battery has a lot of energy in it,” said Dr Less. “If the energy is released in a way that we don’t want it to be released, a fire — or even an explosion — can occur.”

The term “runaway thermal event” appears frequently in these reports, referring to a phenomenon where the battery enters an uncontrollable, self-heating state.

“Thermal containment bag”, an item that only became commonplace on airplanes in 2016 (following a number of explosions of Samsung Galaxy Note 7 smartphones) are fire-containment bags capable of sealing up an overheating battery-operated device to prevent a midair disaster.

Hundreds of thousands of these things are being made per hour. In that mass production process, if something goes wrong even a little bit, it might be very difficult to catch.

From the manufacturing standpoint, there are a lot of pieces and processes that go into making the battery work. If any of those prices go wrong, if there’s a chance for energy to be released.

The reason this happens is because the electrolyte inside the battery is an organic solvent and that solvent is flammable. If the battery can’t vent, it builds up pressure as electrolyte burns, and then it explodes.

The small manufacturing mistakes lead to big problems down the line. In previous instances of batteries catching fire, the course has been bad welds, according to Dr. Less.

Signs that a battery is damaged includes bulging or cracking, hissing, leaking, rising temperature, and smoking before use, according to the Occupational Safety and Health Administration (OSHA).

Damaged batteries should never be carried onto airplanes. If a passenger notices signs of damage or problems once on board, the flight attendant should be notified.

Lithium battery fire is considered a “Class B” fire, according to the US Federal Aviation Administration (FAA). Some common causes of Class B fire include:

Here are comparisons between Class B fires and other classes:

Understanding the distinctions is essential for effective fire suppression –using the wrong suppression method can pose significant dangers, so it is important to accurately identify the cause. (Source: FAA)

Industry data shows there has been an increasing trend in the number of lithium-ion battery fires aboard flights. FAA reported that incidents involving lithium-ion battery fires have surged by over 42 per cent from 2018 to 2022.

There's been a total of nearly 500 reported incidents of lithium battery fires on flights (including more than 60 in 2023 alone), FAA reported.

Instances of overheated lithium batteries leading to smoke, fire, or extreme heat on aircraft are now occurring at an average rate of more than one per week.

These fires can be particularly dangerous. Due to their sudden volatility and the presence of heavy metals in the electronics, they can be difficult to fight.

Experts note that the most dangerous component of these fires is often the smoke – which can proliferate quickly through the cabin, and which contains many harmful and potentially deadly chemicals.

At a forum organised by ViewTech, a manufacturer of borescopes and visual testing equipment, FAA Executive Director Ben Supko highlighted the importance of proper training and awareness for identifying and fighting dangerous events triggered by lithium battery fires on board.

Supko pointed out the best and most “repeatable steps” for extinguishing a lithium battery fire safely are as follows: