Episodes of this type occur periodically, raising a common question: does transporting portable batteries at altitude pose a risk? Power banks can only overheat and generate flames if they have manufacturing defects, are damaged, overcharged or exposed to extreme temperatures. Starting from March 27, 2026, the regulation provides that:Each passenger can carry a maximum of 2 power banks with a capacity not exceeding 100Wh each. The chemistry of lithium batteries: what is “thermal runaway”To understand why a damaged power bank can catch fire, it is necessary to analyze its internal functioning and the chemical-physical process known as thermal runaway (thermal runaway). Using certified batteries, in good condition and complying with ICAO regulations remains the main method to guarantee safety on board.