Lithium-ion batteries, found in power banks, laptops, and vapes, are restricted to carry-on baggage because they can overheat and trigger “thermal runaway.” If a fire starts in the cargo hold, automated systems cannot cool the chemical reaction, whereas cabin crews can quickly contain it.
- Thermal Runaway Risk: Damaged, short-circuited, or poorly manufactured batteries can overheat, release flammable gases, and explode.
- Hold vs. Cabin Response: Cargo suppression systems cannot extinguish lithium battery fires, while cabin crews use specialized thermal bags to stop them.
- Strict Spare Rules: Loose batteries and power banks are completely banned in checked bags, while installed devices must be powered off.
Aviation safety agencies have tightened enforcement on lithium-ion batteries as in-flight thermal incidents rose by 15% from 2024 to 2025. The Federal Aviation Administration (FAA) and international airlines require passengers to keep these power sources in carry-on bags to prevent cargo fires.
While rechargeable batteries are standard in modern electronics, they pose safety hazards during flight. Understanding the science behind battery fires and the specific rules for air travel helps ensure passenger safety.
Understanding Thermal Runaway and the Cargo Hold Hazard
Rechargeable electronics rely on lithium-ion chemistry to store energy. When these cells fail, they can enter a state known as thermal runaway. This is an uncontrollable rise in temperature and pressure that generates toxic, flammable gases and intense heat.
Physical damage, manufacturing defects, exposure to extreme temperatures, or fast charging can damage the internal separator of the battery. Kelly Ransdell, the director of public education for the National Fire Protection Association, explains that when this separator is compromised, the battery overheats, perforates, and explodes.
The primary danger on an aircraft is the location of the device. If a battery fails in the cargo hold, the crew cannot access it. According to the International Air Transport Association (IATA), immediate action is impossible from the cabin. While cargo holds have automated fire suppression systems, like Halon, these systems only suppress open flames. They do not cool the internal chemical reaction of the battery, meaning it can continuously re-ignite surrounding luggage.
In contrast, flight crews are trained to handle lithium battery fires in the cabin. Passengers can alert the crew the moment a device starts swelling, smoking, or burning, allowing for rapid containment.
Distinguishing Between Approved and Unlisted Devices
Not all electronic devices carry the same level of risk. Cellphones and laptops are typically “listed” products. According to Ransdell, this means they meet minimum safety standards that ensure they perform reliably under normal conditions.
However, many portable chargers, e-cigarettes, and vapes are “unlisted.” These cheaper or counterfeit products often fail to meet quality standards. Ransdell notes that the materials used in unlisted electronics are more prone to failure. Counterfeit products purchased from discount online retailers may even carry fake safety stamps.
To minimize risk, travelers should purchase rechargeable devices directly from reputable retailers. The Occupational Safety and Health Administration maintains a database of approved listing agencies, which consumers can use to verify product safety before traveling.
Comparing Checked vs. Carry-On Battery Rules
Aviation authorities enforce rules regarding where batteries can be stored. The tightest restrictions apply to spare, uninstalled lithium batteries and power banks.
According to the Federal Aviation Administration (FAA), all spare lithium-ion and lithium-metal batteries must be kept in carry-on baggage. This includes external battery packs, charging cases, and loose camera batteries.
Devices with built-in batteries, such as laptops and tablets, are permitted in checked bags under specific conditions. The FAA guidelines state that these devices must be completely powered off—not left in sleep or hibernate mode—and protected from accidental activation.
Battery capacity also dictates transport rules. Batteries rated up to 100 watt-hours (Wh) are allowed in carry-on bags. Those between 101 and 160 Wh require airline approval, and any battery exceeding 160 Wh is forbidden on passenger aircraft.
| Battery / Device Type | Checked Luggage | Carry-On Luggage | Key Requirements |
|---|---|---|---|
| Spare Lithium Batteries & Power Banks | Banned | Allowed | Must be under 100 Wh (100–160 Wh requires airline approval). Terminals must be insulated. |
| E-Cigarettes & Vapes | Banned | Allowed | Must stay in the cabin; heating elements must be protected against accidental activation. |
| Installed Devices (Laptops, Phones) | Discouraged | Preferred | Permitted in checked bags only if completely powered off and protected from activation. |
| Alkaline Batteries (AA, AAA, C, D) | Allowed | Allowed | Must be secured to prevent contact with metal objects or other battery terminals. |
Real-World Incidents and Rising Flight Risks
These regulations address a growing safety concern. The FAA tracked 97 battery-related incidents involving smoke, fire, or extreme heat in 2025 alone. Cell phones accounted for 21 of these cases, while laptops were responsible for 8. Since 2006, portable chargers have caused 39% of in-flight lithium battery incidents, and vape pens have caused 21%.
A recent incident on an American Airlines flight highlights the danger. A laptop battery caught fire in the cabin, injuring several passengers. Flight attendants used a thermal containment bag to extinguish the flames. Had this device been in the cargo hold, the fire could have spread undetected.
Best Practices for Safe Air Travel with Electronics
To prevent battery fires, travelers should follow safe handling and charging practices. Ransdell suggests the mnemonic: “Keep it in sight when you’re in flight.” Keeping rechargeable devices within arm’s reach ensures the flight crew can respond quickly if a device begins to overheat.
If gate agents require you to check your carry-on bag at the boarding gate, you must remove all power banks, spare batteries, and vapes before handing the bag over. The rules for batteries on a plane require these items to remain in the cabin at all times.
At home or in hotels, avoid charging devices on soft surfaces like beds, carpets, or furniture, as these materials trap heat. Unplug devices once they reach full charge. Prolonged charging can degrade the battery and make it unstable.
Finally, monitor devices for warning signs of battery failure. These include swelling, discoloration, unusual noises, odd odors, or excessive heat. Damaged, swollen, or recalled batteries should never be brought onto an aircraft.
