What not to pack in your checked bag — the traveller's power safety checklist

The cargo hold of a commercial aircraft has no crew access during flight. If a lithium battery ignites in checked luggage, it cannot be manually suppressed — the halon fire suppression system in the hold can slow a standard fire, but is largely ineffective against a lithium battery thermal runaway.

Lithium battery incidents on commercial flights increased significantly from 2023 through 2025, prompting the UK Civil Aviation Authority to declare it the number-one safety risk to commercial aviation. The problem isn't that lithium batteries are unreliable under normal conditions — it's that a damaged, counterfeit, or overheated cell can enter thermal runaway rapidly, and in the hold that becomes a serious emergency.

The rules below aren't bureaucratic red tape. They exist because keeping lithium batteries in the cabin means a crew member can spot and respond to a problem immediately, often with a containment bag, before it becomes catastrophic.

• Power banks and portable chargers — any capacity, any brand. This includes slim card-style chargers and battery cases for phones. Since March 2026, the limit is also two per passenger maximum. Full 2026 power bank rules →
• Spare (uninstalled) lithium batteries — loose AA or AAA lithium cells, spare camera batteries, spare drone batteries, spare laptop batteries not installed in a device. All must be in the cabin.
• E-cigarettes, vapes, and electronic smoking devices — including disposable vapes, pod systems, and heat-not-burn devices like IQOS. The heating element and battery combination makes these a specific risk.
• Smart luggage with non-removable lithium batteries — many airlines ban smart bags with integrated batteries that cannot be removed. If the battery can be removed, take it out and carry it on; the bag can then be checked.
• Hoverboards and personal electric vehicles — the large batteries required make these banned from most commercial flights entirely, checked or carry-on.

Personal electronic devices with batteries installed inside them — phones, laptops, tablets, cameras, e-readers — are permitted in checked baggage under FAA and TSA rules, as long as they are powered off. However, aviation authorities and airlines consistently recommend carrying them in the cabin instead. The reasons are practical:

• If a device malfunctions, crew can see and respond
• Checked baggage is exposed to temperature extremes and physical handling that can stress batteries
• Theft from checked luggage is more common than most travellers expect

The rule of thumb: if it has a lithium battery and fits in your carry-on, keep it with you.

Regardless of where you try to pack them, these batteries are not permitted on board:

• Visibly swollen batteries — a swollen or puffy battery is already in early-stage failure. Do not fly with it. Dispose of it at an electronics recycler before your trip.
• Batteries with damaged casing, exposed contacts, or signs of leakage — physical damage significantly increases the risk of thermal runaway.
• Batteries that have recently overheated — if a device or power bank got very hot during charging, treat it as suspect.
• Power banks over 160Wh — banned from all passenger aircraft as of March 2026, even with airline approval.

If you're unsure whether a battery is safe, don't bring it. A replacement is cheaper than the alternative.

Cheap, unbranded travel adapters are a separate but related risk. When a counterfeit or uncertified adapter overheats or fails, it can damage expensive devices — or start a fire in a hotel room. Before you travel, check your adapters and chargers for these certification marks:

Mark	What it means	Where required
CE	Meets EU electrical safety standards	EU / UK (as UKCA)
UL / ETL	Third-party tested to US safety standards	North America
FCC	Meets US radio frequency standards	USA
RCM	Meets Australian/New Zealand standards	Australia / NZ

If your adapter has none of these markings — just a brand name or no markings at all — that's a warning sign. Certified adapters from established brands cost only a few dollars more than uncertified ones and are meaningfully safer.

Also check: does the adapter have a fuse or surge protection? Universal adapters that include both are worth the small premium, particularly in countries where mains power quality is inconsistent.

Run through this before every international trip:

• ✓ Power banks in carry-on bag — not checked luggage
• ✓ Maximum two power banks per person
• ✓ Each power bank is 100Wh or under (check the label)
• ✓ Spare batteries in carry-on, contacts protected with tape or original packaging
• ✓ Vapes and e-cigarettes in carry-on
• ✓ No swollen, damaged, or recently overheated batteries in your kit
• ✓ Plug adapter has CE, UL, ETL, or FCC certification marking
• ✓ Adapter or charger rated 100–240V for your destination's voltage