A passenger boards with a perfectly ordinary 20,000 mAh power bank.
Security accepts it.
The airline allows it in the cabin.
The passenger sits down, connects an iPhone and assumes everything is fine.
Then the cabin crew tells them to disconnect it.
Nothing is necessarily wrong with the battery.
The rules have changed.
In 2026, the important question is no longer simply:
Can I bring a power bank on a plane?
You now need to ask three separate questions:
- Can I carry it?
- Where must I store it?
- Can I actually use it during the flight?
Those answers can be different.
Rule number one: never put a power bank in checked luggage
This is the easiest rule to remember.
Power banks are treated as spare lithium batteries and belong in carry-on baggage, not checked luggage.
IATA’s current passenger guidance says spare batteries and power banks must be carried in hand baggage and protected against short circuits.
That means this is wrong:
Large suitcase
→ power bank
→ checked at deskThe correct setup is:
Backpack / cabin bag
→ power bank
→ stays with passengerAnd there is another trap.
If the airline takes your cabin bag at the gate and sends it to the hold, remove your power bank first.
IATA specifically tells travellers to remove lithium batteries and devices when carry-on baggage is gate-checked.
The number that matters is Wh, not mAh
Most shoppers see:
10,000 mAh
20,000 mAh
27,000 mAhAirlines care primarily about:
Watt-hours — WhIATA’s general framework is:
Up to 100 Wh
→ generally allowed in carry-on
100–160 Wh
→ airline approval may be required
Over 160 Wh
→ generally not permitted on passenger aircraftThis is why a giant power bank bought online can create trouble even though it looks like an ordinary consumer accessory.
How to calculate Wh yourself
Use:
Wh = Ah × VoltageBecause:
1,000 mAh = 1 AhA typical 20,000 mAh power bank using a nominal cell voltage around 3.7 V works out approximately as:
20 Ah × 3.7 V = 74 WhThat normally falls below the 100 Wh threshold.
A 27,000 mAh unit:
27 Ah × 3.7 V = 99.9 WhNow you can see why many large travel power banks are designed around roughly this capacity.
But do not rely only on your own calculation.
Check the rating printed on the device.
Some airlines explicitly require the capacity information to be visible.
Emirates, for example, currently requires its permitted power bank to have its capacity rating clearly marked.
2026 changed the game
ICAO introduced updated power-bank requirements in March 2026, and airlines and regulators have been implementing increasingly restrictive policies.
Singapore’s aviation regulator introduced new restrictions from April 15, 2026, including a maximum of two power banks per passenger on flights departing Singapore and a prohibition on charging power banks onboard.
The direction is clear:
Carrying a power bank and using a power bank are becoming two different permissions.
Emirates: you may carry it, but you may not use it
Emirates provides one of the clearest examples.
Its current policy allows a passenger to carry one power bank below 100 Wh, but:
- it cannot be used to charge another device onboard;
- it cannot itself be charged onboard;
- it cannot be placed in an overhead locker;
- it must remain under the seat, in the seat pocket or otherwise readily accessible;
- it cannot be placed in checked baggage.
So this is possible:
Power bank in cabin: YES
Power bank charging phone:
NOThat distinction catches travellers by surprise.
Lufthansa is similarly strict
Lufthansa currently states that power banks are not allowed in checked baggage and lists a maximum of two per passenger.
It also states that charging or using power banks onboard is prohibited, except for certain approved medical-device applications.
The airline instructs passengers not to store them in overhead lockers and instead keep them accessible under the seat, in a seat pocket, on the person or appropriately in hand baggage.
Again:
Being allowed to carry it does not mean being allowed to use it.
Singapore Airlines: two power banks, but no onboard use
Singapore Airlines currently permits up to two power banks per passenger.
Its rules specify:
Up to 100 Wh:
Allowed without prior approval
100–160 Wh:
Approval required
Above 160 Wh:
Not allowedBut it also prohibits using a power bank to charge personal devices during the flight and prohibits charging the power bank through the aircraft’s power supply.
That is why copying one airline’s rules and applying them to another is increasingly risky.
Why overhead lockers are becoming a problem
A damaged lithium-ion battery can enter thermal runaway.
If a power bank begins:
- overheating;
- swelling;
- smoking;
- producing an unusual smell;
the crew needs to know quickly.
A battery buried inside a backpack inside an overhead locker is harder to notice and access than one stored near the passenger.
That is why several newer policies specifically address where the power bank sits during the flight, not merely whether it is onboard.
The practical 2026 rule is:
Keep it accessible.
Do not bury it.
Do not place it in checked luggage.The Fintayo pre-flight test
Before leaving home, look at your power bank.
You should be able to identify:
Capacity:
_____ Wh
or
Capacity:
_____ mAh
Rated voltage:
_____ VIf the label is worn away or impossible to read, I would not choose that unit for international travel.
Even if the battery is technically within limits, airport or airline staff may not be willing to accept an unidentifiable lithium battery.
A €25 replacement is cheaper than arguing at the gate.
What about 10,000 mAh?
For ordinary phone use, this is often the easiest travel size.
A typical 10,000 mAh unit at 3.7 V is roughly:
10 Ah × 3.7 V
=
37 WhWell below 100 Wh.
It is also:
- lighter;
- easier to keep accessible;
- enough for roughly one or more smartphone recharges depending on device and conversion losses;
- less likely to create capacity questions.
For many travellers, buying a huge battery just because it exists creates unnecessary weight.
20,000 mAh is the practical heavy-use sweet spot
Illustrative calculation:
20 Ah × 3.7 V
=
74 WhThat typically remains comfortably below 100 Wh.
It makes sense for:
- long travel days;
- two phones;
- tablet use;
- photography;
- multiple connections;
- destinations where power access is unreliable.
But remember:
A larger battery does not help during a flight where the airline prohibits using it.
In that scenario, pre-charging your phone before boarding becomes more important.
A 27,000 mAh power bank deserves extra attention
Illustrative calculation:
27 Ah × 3.7 V
=
99.9 WhThat sits almost exactly on the common 100 Wh threshold.
This is not a problem when the manufacturer’s official rating is compliant and clearly marked.
But it leaves little margin for ambiguity.
For simple travel, I would generally choose a clearly labelled unit comfortably below 100 Wh rather than trying to maximize every last watt-hour.
Do not confuse USB output watts with battery Wh
A power bank might advertise:
65W
100W
140WThat is usually charging power output.
It is not the same as:
100 Whbattery energy capacity.
A 100W USB-C power bank can still contain less than 100 Wh of energy.
The two measurements answer different questions.
W = how fast power can be delivered
Wh = how much energy the battery storesAirline limits focus primarily on battery energy capacity.
Another mistake: power bank inside smart luggage
Some suitcases include integrated charging batteries.
IATA says a power bank installed in baggage generally needs to be removable so that it can be taken into the cabin if the bag is checked.
A bag with a non-removable battery may be refused depending on its design and airline requirements.
Before buying “smart luggage,” ask:
Can the battery be removed in 10 seconds?If the answer is no, the clever feature may create a very inconvenient airport problem.
AirTag is different
An AirTag is not treated like a 20,000 mAh power bank.
IATA’s current lithium-battery fact sheet notes a specific exception allowing small low-energy baggage tracking devices such as AirTags to remain active in checked baggage when they meet the applicable tiny-battery limits.
That is why this can be permitted:
AirTag inside checked suitcasewhile this is not:
20,000 mAh power bank inside checked suitcaseDifferent battery size.
Different function.
Different rule.
The gate-check trap
Imagine your cabin bag contains:
Laptop
Power bank
Camera batteries
HeadphonesThe flight is full.
At the gate you hear:
“Your bag needs to go in the hold.”
Do not simply hand it over.
Remove the restricted lithium items first.
IATA explicitly highlights this scenario in its traveller safety guidance.
Keep a small pouch near the top of your cabin bag containing:
Power bank
Spare camera batteries
Important electronics
Passport
MedicationIf the bag is gate-checked, the pouch comes out in seconds.
The best 2026 packing position
Our preferred arrangement:
Small protective pouch
↓
Inside personal item
↓
Under seat
↓
Easy to reachNot:
Power bank
↓
Bottom of trolley
↓
Overhead locker
↓
Behind six other bagsProtect the terminals and prevent metal objects from creating a short circuit.
IATA recommends original packaging, terminal protection or an appropriate protective case.
Before every flight, check the airline
This is the most important 2026 change.
There is no longer one simple sentence that covers every airline.
One airline may allow:
2 × under 100 WhAnother:
1 × under 100 WhAnother may permit carriage but prohibit use.
Rules may also differ because of national aviation requirements.
IATA explicitly tells passengers to check their airline because carrier and local restrictions can differ.
Copy-and-paste Power Bank Travel Check
AIRLINE:
ROUTE:
POWER BANK BRAND:
MODEL:
CAPACITY:
_____ mAh
RATED ENERGY:
_____ Wh
================================
[ ] Under 100 Wh
[ ] Rating clearly visible
[ ] Not damaged/swollen
[ ] Carry-on only
[ ] Terminals protected
[ ] Airline quantity limit checked
[ ] Onboard-use policy checked
[ ] Overhead-storage rule checked
================================
IF CABIN BAG IS GATE-CHECKED:
[ ] Remove power bank
[ ] Remove spare batteries
[ ] Keep them in personal itemThe Fintayo takeaway
The old advice was:
Put your power bank in your carry-on.
In 2026, that is no longer enough.
The better rule is:
Check the Wh rating, keep it in the cabin, keep it accessible and confirm whether your airline actually allows you to use it.
The most important number on a travel power bank may not be 20,000 mAh.
It is:
WhAnd the most expensive mistake may be discovering the airline’s battery policy after you arrive at the gate.
