Can you bring a power bank on a plane in 2026? The rules airlines don't explain well
Yes — but the answer changed in March, and the part that catches people out is no longer the watt-hour limit. It's how many you carry, where you put them, and whether you plug one in at cruising altitude.
Every guide to flying with a power bank quotes the same number: 100 watt-hours. It is a real limit and it still applies, but treating it as the whole rule is how travellers end up surrendering a bank at the gate. Since 27 March 2026, when a revised set of ICAO provisions took effect across member states, the constraints that actually bite most passengers are different ones — and they are the ones airlines communicate worst.
Here is what changed, what stayed the same, and how to check your own bank in about fifteen seconds.
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The short answer
- Under 100 Wh: allowed in carry-on, no approval needed. This covers almost every consumer power bank sold.
- 100–160 Wh: allowed in carry-on only with your airline's advance approval, and a maximum of two.
- Over 160 Wh: banned from passenger aircraft entirely.
- Checked baggage: never, at any capacity.
- Quantity: a maximum of two power banks in the cabin under the 2026 provisions.
- In flight: charging from or to a power bank is prohibited on a growing list of carriers.
Watt-hours: the number that decides everything
Aviation rules are written in watt-hours (Wh), which measures stored energy. Power banks are marketed in milliamp-hours (mAh), which does not — it measures charge, and it is meaningless for this purpose without the voltage that goes with it. This mismatch is the single biggest source of confusion at security.
The conversion is simple:
Wh = (mAh ÷ 1000) × V
Nearly every lithium-ion cell in a consumer power bank has a nominal voltage of 3.7 V, so the practical version of that formula is mAh ÷ 1000 × 3.7. A 20,000 mAh bank is therefore 74 Wh — comfortably legal. A 27,000 mAh bank is 99.9 Wh, which is legal but sits right on the line. Anything advertised at 30,000 mAh or above is likely over 100 Wh and needs airline approval.
| Capacity (at 3.7 V) | Watt-hours | Status |
|---|---|---|
| 10,000 mAh | 37 Wh | Carry-on, no approval |
| 20,000 mAh | 74 Wh | Carry-on, no approval |
| 26,800 mAh | 99.2 Wh | Carry-on, no approval — but only just |
| 30,000 mAh | 111 Wh | Airline approval required, max two |
| 40,000 mAh | 148 Wh | Airline approval required, max two |
| 50,000 mAh | 185 Wh | Prohibited |
The 26,800 mAh figure is not a coincidence. It is the largest round capacity that stays under 100 Wh at 3.7 V, which is exactly why so many "travel" power banks cluster at that number.
Careful with high-voltage banks
Some laptop banks use cells in series at 7.4 V or 11.1 V. The 3.7 V shortcut does not apply to those, and a bank with a modest-looking mAh figure can easily exceed 100 Wh. If your bank charges a laptop over USB-C PD at high wattage, read the printed Wh figure rather than calculating.
How to read the label on your bank
Look at the bank itself, not the box — you almost certainly threw the box away. The capacity is printed on the casing, usually in small grey text on the underside or along one edge. There are three possibilities:
- A Wh figure is printed. Best case. That number is what a screening officer will use, and no arithmetic is needed.
- Only mAh and a voltage are printed. Apply the formula above. Write the result on a small label and stick it to the bank; it converts a possible argument into a five-second glance.
- Nothing legible is printed. This is the genuinely risky case. An unmarked bank can be refused on the spot regardless of its actual capacity, because the officer has no way to verify it. If you fly with any regularity, replace it.
What changed in March 2026
Three things, and none of them concern the watt-hour thresholds, which are unchanged.
A hard cap of two banks in the cabin
Passengers may now carry a maximum of two power banks. Previously the limit applied only to the larger 101–160 Wh class; it now applies as a general cabin limit. If you routinely travel with a small bank for your phone, a bigger one for a laptop and a spare in the camera bag, you are one bank over.
No charging in flight
The provision most passengers discover only when a crew member asks them to unplug: using a power bank during the flight — charging a device from it, or charging the bank itself from a seat USB port — is prohibited. The reasoning is thermal. A cell that fails while idle in a seat pocket announces itself with smoke; a cell that fails mid-charge does so faster and hotter.
Keep them where the crew can reach them
Power banks must stay accessible in the cabin rather than buried in the overhead bin. This followed a series of in-cabin battery fires, including a widely reported incident on Air China flight CA139 in October 2025, in which crew response time was the deciding factor. A seat pocket or the top of your bag under the seat satisfies this; the bottom of a roller bag in the bin does not.
Why checked luggage is an absolute no
The TSA's wording leaves no room for interpretation: spare lithium-ion batteries, power banks included, must be carried in carry-on baggage only. This is not a bureaucratic preference. A lithium cell entering thermal runaway in the cabin is a manageable event — there are fire containment bags on board and crew trained to use them. The same event in a cargo hold, unobserved, is not.
The same logic explains why the rule is about spare batteries. A battery installed inside a device can travel in checked baggage; a loose one cannot.
Airline-by-airline variation
ICAO provisions set a floor, not a ceiling. Individual carriers may be stricter, and several are. Emirates, Qatar Airways, Singapore Airlines, Air India, Cathay Pacific, British Airways and the Lufthansa Group — including SWISS, Austrian and Brussels Airlines — have all aligned with or gone beyond the 2026 standard, and major US carriers have introduced their own versions.
Two practical consequences. First, the approval process for a 101–160 Wh bank differs by airline: some handle it at check-in, others require a form days in advance, and a few decline outright. Second, "my last airline allowed it" carries no weight. Check the specific carrier, on the specific route, before you pack.
Codeshares catch people out
If you booked with one airline but the aircraft is operated by another, the operating carrier's rules apply — not the one on your booking confirmation. Check the airline named on the boarding pass as operator.
What to do before your next flight
- Find the Wh figure on each bank you plan to bring. Calculate it if only mAh is printed.
- Count your banks. If it is more than two, leave the extras at home.
- Move all of them into your carry-on, and into a pocket you can reach from your seat.
- If any bank is over 100 Wh, contact your airline for approval — allow several days.
- Charge everything on the ground. Assume you will not be allowed to use a bank in the air.
- Discard any bank with an unreadable label, and any that is visibly swollen. A swollen bank should not be in a bag at all, let alone on an aircraft.
None of this is difficult. It only causes trouble because the number everyone memorised — 100 Wh — is no longer the number that decides whether you keep your bank at the gate.