Airlines clamp down on lithium batteries amid uptick in thermal events
Kevin J. Harrigan | March 14, 2025
Source: Kateryna Muzhevska/Adobe Stock
Make no mistake, lithium (Li)-ion thermal runaway is a rare occurrence. Some estimates place it at less than one-in-one million Li-ion batteries will experience a thermal event. Probability increases as more cells and complex or poor manufacturing process are introduced. In many thermal runaway cases, those events are preventable, as it is usually preceded by poor QA/QC, damage, overcharging or improper use.
However, due to the highly volatile nature of Li metal fires, airlines and aerospace regulators are increasingly scrutinizing the presence and care of Li-ion batteries on passenger aircraft. For example, the U.S. Federal Aviation Administration maintains a policy that all Li batteries must fly with their owners in the cabin, either in their personal or carry-on baggage. This is so Li fires can be recognized and addressed by the do-it-all flight attendants on commercial airliners.
However, airlines are free to set more restrictive policies on Li batteries on their aircraft. Many have done just this, after more than 80 Li battery issues were reported by global airlines in 2024, even though none resulted in loss of life.
Airlines in Asia recently announced additional restrictions on the use and location of chargers and power banks. This is in response to a January 2025 Air Busan flight that was grounded by a cabin fire at Gimhae International Airport, South Korea. All passenger and crew evacuated safely before the plane took off. The ensuing investigation has zeroed in on a Li battery as the likely cause.
Those restrictions, effective March 1, include that passengers on South Korean airlines must keep their portable chargers within arm's reach and out of overhead bins. EVA Air, China Airlines, Thai Airways, Singapore Airlines and Scoot have since introduced bans on portable power banks.
Li-ion batteries have become the standard rechargeable power storage medium for most varieties of personal electronics. As the electronics industry has grown, so too has the demand and presence of Li-ion batteries. Many batteries are regulated or standardized at the device level, although that criterion is far from universal.
This patchwork approach to transporting batteries on planes, or increasing their reliability to a higher, common standard, will undoubtedly create frustration for international passengers. And that frustration may grow, as airlines may continue to implement their own, differing policies.
I can't blame them for tightening up the rules regarding Li batteries.
On the flip side, put at least one USB charging port for every seat and people won't need to bring aboard these Li-Ion Bricks.
At least devices from reputable electronics firms have vetted OEM cells. These re-charging bricks can be made by dozens of different or the same company with some obscure name that can disappear and pop up somewhere else with a different moniker.
I could potentially see where the UL or some other testing authority is going to set up a certification process that will meet the needs of the airline industry. I'm sort of surprised this has not come up yet. Not that the TSA needs yet something else to check, but it's only a matter of time until a disaster does happen that traces back to some Li-Ion mishap.
I haven't seen it yet, but I imagine there is a standard procedure for the flight crew when an event occurs to contain the heat and limit the smoke. Galley sink with water perhaps? An insulated 'burn bag' that can be filled with any available non-flammable aqueous fluid? Soda, water, tea, coffee, etc. Needs to be large enough for a laptop. Bomb bay doors?