The portable charger has become one of the most universal travel accessories in existence. Americans pack them for every trip, use them in airport terminals while waiting for flights, and rely on them to keep phones, tablets, and earbuds alive during long hauls. They sit in backpacks and tote bags alongside boarding passes and snacks, treated as essentially harmless convenience items. They are not harmless. Aviation safety regulators are now warning that power banks are generating a growing number of serious incidents on commercial flights, and the rules governing how they can be transported are strict, specific, and being violated by passengers with enough regularity to prompt a formal safety campaign.
The UK’s Civil Aviation Authority has issued a direct warning that portable chargers carry serious risks of overheating and catching fire, and that incidents involving these devices are on the rise. This is not a theoretical concern or a precautionary announcement made in the absence of evidence. It is a response to documented incidents, including a flight that was diverted to Rome last week after a passenger packed a power bank in checked luggage. For American travelers who carry power banks on virtually every trip they take, understanding the specific rules and the reasons they exist is not optional information. It is information that has direct consequences for personal safety, flight safety, and the itineraries of everyone else on the aircraft.
The Flight Diversion That Made the Warning Urgent
Last week, an EasyJet flight from Hurghada in Egypt to London was diverted mid-journey to Rome Fiumicino Airport after a passenger informed cabin crew that a portable charger had been placed in the aircraft’s hold luggage. The flight changed course as a precautionary measure, and the 150-plus passengers on board were required to remain in Rome overnight before a rescheduled flight to London the following day.
No fire occurred. No emergency situation developed beyond the diversion itself. But the diversion happened precisely because the risk of a fire in the hold was considered serious enough to change the aircraft’s destination and strand every passenger on board in a different city. A single passenger’s decision to pack a power bank in checked luggage, which is unambiguously prohibited under international aviation rules, disrupted the plans of every other person on that flight.
This is the scenario that aviation safety officials want American travelers to hold in their minds when they are packing for a trip. The rule against placing power banks in checked luggage is not a bureaucratic technicality or an abundance of caution. It is a rule designed to prevent a lithium-ion battery fire in an aircraft hold, where the fire would be significantly harder to detect and suppress than one that occurs in the cabin. The diversion to Rome was the best-case outcome of the rule being broken. A fire in the hold at altitude is not a best-case outcome.
Why Lithium-Ion Batteries in Aircraft Holds Are Dangerous
Understanding why the rules exist requires a brief look at what lithium-ion batteries do when they fail, and why the location of that failure within an aircraft matters so much.
Lithium-ion batteries power virtually every rechargeable device that modern travelers carry: phones, tablets, laptops, wireless headphones, e-readers, and power banks. When these batteries fail in a process called thermal runaway, they do not simply stop working. They generate intense heat very rapidly, can produce flames, and in some cases rupture and release burning electrolyte material. The failure can cascade from one battery cell to adjacent ones, amplifying the heat and fire output significantly.
Commercial aircraft carry fire suppression systems, and cabin crew are trained to respond to battery fires. In the cabin, a battery fire is visible immediately, can be addressed by crew, and can be managed with the fire suppression equipment carried on board. In the hold, where checked luggage is stored, a battery fire may not be detected quickly, may spread to surrounding luggage before anyone is aware of it, and is much harder to access for suppression. The hold fire suppression systems on commercial aircraft are designed for cargo fires, not for the concentrated, rapid heat of a thermal runaway event in a lithium-ion battery.
Power banks present a specific and elevated version of this risk compared to other lithium-ion devices because of their design purpose. A power bank exists to store large amounts of electrical energy in a compact form and deliver it reliably on demand. That means they contain larger battery cell configurations than a phone or a pair of wireless earbuds, they generate more heat when they fail, and they carry more stored energy to feed a fire if one starts. Aviation safety officials have been explicit that power banks are considerably more dangerous in this context than the other rechargeable devices that travelers routinely carry.
The Numbers Behind the Warning
The urgency of the current safety campaign is grounded in data that has been systematically collected over the past several years. A US-based safety organization, UL Standards and Engagement, has been tracking incidents involving lithium-ion batteries on commercial flights since 2019. The data, compiled through voluntary reporting from 37 passenger and cargo airlines, documented an average of two incidents per week in 2024 in which lithium-ion batteries on commercial flights experienced thermal runaway events. That figure represents a 15 percent increase between 2019 and 2024.
Two incidents per week globally may sound manageable in the context of millions of commercial flights annually, but the trend line is the relevant concern. As portable chargers, vaping devices, and other lithium-ion battery products become more prevalent among travelers, the rate of incidents is increasing proportionally. Aviation regulators are warning that without better passenger awareness and compliance with existing rules, that trend will continue.
The incidents covered by the data include all lithium-ion devices, not only power banks. Phones, laptops, tablets, and other rechargeable devices all contribute to the total. But power banks are specifically identified by aviation safety officials as among the highest-risk items in this category because of their battery capacity and the fact that passengers tend to treat them with considerably less care than they apply to their phones or laptops.
The awareness gap is a documented part of the problem. A survey of a thousand passengers found that more than a third were aware that rules about lithium batteries existed but were uncertain about what those rules specifically required. That is a substantial proportion of travelers who know they should do something different but do not know what. For American travelers who make up a large share of passengers on international flights, the specific rules are straightforward and worth committing to memory before the next trip.
The Rules That Apply to Every American Traveler on Every Flight
The rules governing power banks on commercial flights are set by international aviation standards and apply universally, including on every flight departing from or arriving at American airports. They are not optional guidelines or suggestions. They are requirements, and violating them can result in flight diversions, confiscated devices, and in some airports, additional scrutiny at security checkpoints.
The fundamental rule is that portable chargers must travel in carry-on luggage, not in checked bags. This is the rule whose violation caused the diversion to Rome, and it is the single most important thing American travelers need to understand about power banks and air travel. If a power bank is in your checked luggage when you check in, it needs to come out and go into your carry-on before your bag goes onto the aircraft. No exceptions.
Each passenger is permitted to carry a maximum of two power banks. This limit exists to cap the amount of lithium-ion battery energy that any individual passenger can introduce into the cabin, and it applies regardless of the capacity of the devices.
Once on board the aircraft, power banks should not be used to charge other devices, and they should absolutely not be charged themselves. Charging a power bank generates the heat that makes thermal runaway most likely to occur. Using a power bank while it is stowed and not actively monitored also creates conditions where a problem could develop without immediate detection. Power banks should be packed away in a bag under the seat in front of you rather than in the overhead compartment, where they are more accessible for monitoring and easier to respond to if an issue develops.
The Quality Problem That Americans Should Take Seriously
Aviation safety officials have raised a concern about power bank quality that has specific relevance for American consumers who purchase inexpensive chargers through online marketplaces.
The dramatic expansion of the portable charger market over the past decade has brought a large number of cheaply manufactured products into circulation, many of which do not meet the quality and safety standards of established electronics manufacturers. Battery cells sourced from low-cost manufacturers, inadequate protection circuitry, and construction that is not built to withstand the physical handling that power banks routinely receive in bags and backpacks all contribute to higher failure rates.
Aviation safety officials have been explicit that the quality of a power bank matters significantly for its fire risk. A well-constructed power bank from a reputable manufacturer with proper protection circuitry is less likely to experience thermal runaway than a cheaper product assembled with lower-quality components. For American travelers who have accumulated multiple power banks over the years, some purchased at deeply discounted prices, it is worth evaluating the quality of the devices being taken on flights.
Physical condition is also relevant. Power banks that have been dropped, sat on, exposed to moisture, or that show any external damage including swelling of the case should not be taken on aircraft. A battery that has been physically damaged is more likely to fail than one that is in good condition, and the consequences of a failure in the aircraft cabin are severe enough that damaged power banks should be retired rather than packed for travel.
Vaping Devices Face the Same Rules
American travelers who use vaping or e-cigarette devices face the same checked luggage prohibition that applies to power banks. Vaping devices contain lithium-ion batteries and are subject to the same fire risk concerns in aircraft holds. Like power banks, they must travel in carry-on luggage rather than checked bags.
Aviation safety officials have specifically noted vaping devices alongside power banks as a growing source of lithium-ion battery incidents on commercial flights, reflecting the rapid growth in vaping device ownership among travelers. For Americans who vape and fly regularly, the rule is the same: the device goes in the carry-on, it does not get charged on the aircraft, and it should not be used during the flight, which is already prohibited by smoking regulations.
What to Do Before Your Next Flight
The practical steps for American travelers are straightforward and do not require any significant change to how most people pack. Check every bag before the airport to confirm that any power banks, vaping devices, or other external battery packs are in carry-on luggage rather than checked bags. Confirm that you are carrying no more than two power banks. Once on board, pack them in the bag under the seat and do not use them to charge devices or charge the power bank itself.
If you are unsure whether a specific device qualifies as a power bank or portable charger, the practical guidance is that any external battery designed to charge other devices falls into this category and should be treated accordingly. Laptop charging cases, portable battery stations, and similar products are all covered by the same rules as standard power banks.
The TSA provides guidance on lithium battery rules on its website, and checking that guidance before any trip ensures you have the current requirements for flying from American airports. Airlines may have slight variations in how they communicate the rules, such as specific preferences for under-seat rather than overhead bin storage, but the core prohibitions are universal and consistent across carriers.
The flight diversion to Rome made a clear and specific point that aviation safety officials want American travelers to absorb: these rules exist because the consequences of ignoring them are real, documented, and significant enough to land a full aircraft in an unplanned city. Packing a power bank correctly takes ten seconds. The alternative is considerably more complicated.
