Onboard lithium-battery incidents across aircraft have risen 15% over the past year, with power banks now the leading source of thermal runaway events, according to UL Standards & Engagement. The trend is being driven by more passengers carrying and using portable chargers in flight, raising both safety and operational concerns for airlines. Nearly one in five onboard thermal-runaway incidents now results in a return to gate, diversion or unplanned deplaning.
David Wroth, vice president for standards, technology and operations at UL Standards & Engagement, linked the increase to the spread of power banks as a routine travel item. Airlines have responded with tighter preflight messaging and policy changes covering how such devices are stored and used onboard.
The issue has drawn fresh attention after an Air Busan aircraft fire in 2025 involving a portable charger. The incident underscored the potential severity of battery failures in the cabin and the disruption they can trigger for operators and passengers alike.