Batteries used in portable devices have been labelled the number one safety hazard for aircraft by the United Kingdom’s national aviation regulator due to an alarming rise in the number of flights disrupted by overheating lithium batteries.
The UK’s Civil Aviation Authority (CAA) has launched a “Pack right. Safe flight” campaign for the high travel season, warning air passengers not to pack personal items that use lithium batteries in hold luggage but instead to carry them into the cabin where they can be constantly monitored for overheating.
The consequences for placing items with rechargeable lithium batteries, including mobile phones, power banks, and vapes, in hold luggage could be devastating because they pose a “fire risk that could be uncontrollable,” the CAA said.
Though some flyers may think rechargeable devices are low-risk, everyday items, they present a danger of so-called “thermal runaway,” which is an uncontainable chain reaction in a battery where excess internal heat causes exothermic chemical reactions. These reactions in turn generate even more heat and so on in a vicious circle, quickly leading to battery failure, the release of toxic and inflammable gases, and the chance of fires or explosions.
We’ve launched a campaign highlighting the threat posed by over 100 million incorrectly packed batteries.
— UK Civil Aviation Authority (@UK_CAA) June 26, 2026
Power banks and vapes must be taken with you into the cabin.
Packing them incorrectly risks delays, or worse, an in-flight fire. pic.twitter.com/2aeo2MZyFf
Common causes of overheating include fast charging at high wattages, charging multiple devices simultaneously, poor ventilation, and ageing, damaged, or defective batteries and cables.
The quantity of such equipment that could be on board a crowded Airbus A380 flight could reach into the thousands if each passenger brought along multiple rechargeable items, so the general rule is two devices only per passenger. The devices must also meet certain safety standards, not exceed power limits, and be carried where they can be seen and easily accessed, not packed away in checked hold baggage.
Yet, CAA data reveals more than a third (36%) of travellers are unaware of the dangers of packing batteries in checked baggage, even though 92% fly with a mobile phone, 55% with a laptop and 49% with a power bank – suggesting hundreds of batteries could be incorrectly packed on a typical flight. In 2024, 316 aviation incidents involving lithium battery devices found in hold bags were reported to UK authorities. In 2025, that figure rose to 643, the CAA said.
Giancarlo Buono, the CAA’s director of aviation safety, said: “Flying is by far the safest way to travel, and we want to keep it that way. Pack right for a safe flight, and that means don’t put your batteries in your checked bag. Take them into the cabin with you. This simple tip will make your flight safer for you and the other passengers you’re flying with.”
The safety campaign is supported by a number of airlines and stakeholders, including Virgin, Airlines UK, Airports UK, and Heathrow Airport. Tonya Fielding, Head of Security at the UK’s busiest hub, said: “We’re pleased to be joining forces with the CAA to raise awareness of the dangers posed by incorrectly packed lithium batteries, with the risks still not fully understood by some travellers. As we approach one of the busiest periods of the year, we are working closely with our airline partners to make sure passengers have clear guidance to travel safely and confidence.”
