A power bank may be labelled 10,000, 20,000 or 30,000 mAh. For air-travel rules, however, the more important figure is Wh — watt-hours.
In 2026, IATA published more specific guidance for power banks. The practical summary is:
- carry power banks in the cabin, not in checked baggage;
- current IATA 2026 guidance limits a passenger to a maximum of two lithium-ion power banks, each no more than 100 Wh;
- a power bank above 100 Wh should not automatically be treated as “allowed with airline approval” — IATA's power-bank guidance dated 31 March 2026 marks the >100–160 Wh range as forbidden;
- an individual airline may impose stricter conditions.
So check Wh + the carrier's policy, not mAh alone.
Why mAh is not enough
mAh measures electric charge, but by itself it does not tell you the stored energy. You also need the nominal voltage.
The formula is:
Wh = Ah × V
or:
Wh = (mAh ÷ 1000) × V
For example, 20,000 mAh at a nominal 3.7 V gives:
20 Ah × 3.7 V = 74 Wh
That is below 100 Wh.
Do not automatically assume 3.7 V for every model. The safest reference is a clearly printed Wh rating on the device or in its technical documentation. If the manufacturer specifies another nominal voltage, the result changes.
Up to 100 Wh: the standard range
IATA passenger guidance for 2026 specifies a maximum of two power banks up to 100 Wh each.
Many 10,000 or 20,000 mAh models fall below that threshold, but do not rely on an estimate. Check the manufacturer's Wh rating.
If the rating is missing or unreadable, acceptance may become a problem. For travel, a model with clearly marked technical data is the safer choice.
Why 100–160 Wh is a special case
General lithium-battery guidance often says batteries between 100 and 160 Wh may be accepted with airline approval. That applies to certain battery and device categories.
Power banks are treated more specifically in IATA's operator guidance dated 31 March 2026. Its table marks power banks above 100 Wh and up to 160 Wh as Forbidden.
Do not therefore transfer the general “100–160 Wh with approval” rule automatically to power banks.
If your unit is above 100 Wh, contact the airline, but do not plan your trip on the assumption that it will normally be accepted.
Do not put a power bank in checked baggage
A power bank is treated as a spare lithium battery and must remain in carry-on baggage.
In practice:
- do not leave it in a suitcase you check in;
- if your cabin bag is taken at the gate and placed in the hold, remove the power bank first and keep it in the cabin.
This matters because a lithium-battery problem needs to be noticed and managed quickly.
Protect against short circuits
Spare batteries and power banks must be packed so their terminals cannot accidentally contact metal objects.
Suitable options include the original packaging, a separate protective case or pocket, or insulating exposed terminals where the design requires it.
Do not leave the device loose in a bag with keys, coins or other metal objects.
Where should it stay during the flight?
IATA's 2026 guidance says power banks should not be stored in overhead baggage compartments.
Some airlines already impose more specific rules, such as keeping the unit in a bag under the seat or another readily accessible place. The general Wh rule is therefore only the first check; the second is the policy of your carrier.
Can you recharge a power bank on the aircraft?
IATA 2026 guidance says a power bank must not be recharged from the aircraft's power supply.
It also must not be used to power other devices during taxi, take-off and landing. An airline may prohibit its use during more of the flight. Being permitted in the cabin does not automatically mean it may be used at all times.
Is a 20,000 mAh power bank allowed?
Often yes, but not merely because the label says 20,000 mAh.
If the label states, for example, 74 Wh, the unit is below 100 Wh. If Wh is absent, use the manufacturer's stated nominal voltage or consult its technical documentation.
Do not calculate with USB output voltages such as 5 V, 9 V or 12 V. For the aviation Wh rating, use the battery energy specification declared by the manufacturer.
What about 30,000 mAh?
That number alone is no longer enough for a reliable answer.
At a nominal 3.7 V:
30 Ah × 3.7 V = 111 Wh
That is above 100 Wh and outside the standard permitted range in the specific IATA 2026 power-bank guidance. Again, use the actual factory Wh rating rather than an approximate calculation when the device is clearly labelled.
Damage matters regardless of Wh
Do not travel with a power bank that is swollen, badly damaged, unusually hot, emitting an odour, or has a compromised case or terminals.
If a device begins to smoke or heat strongly during a flight, alert the cabin crew immediately.
Seven checks before you fly
1. Find the device's Wh rating. 2. Confirm it is 100 Wh or less for the standard IATA 2026 power-bank regime. 3. Do not carry more than two, unless applicable rules explicitly say otherwise. 4. Put them in carry-on baggage, never checked baggage. 5. Protect them against short circuits and physical damage. 6. Check the airline's policy on storage and onboard use. 7. If your cabin bag is moved to the hold at boarding, remove the power bank first.
The key point in 2026
Do not mechanically apply the old shorthand “up to 100 Wh allowed, 100–160 Wh with approval” to every lithium battery.
For power banks, the specific 2026 IATA guidance is stricter: a maximum of two units up to 100 Wh, carried in the cabin, with additional restrictions on storage and use.
The final check should always be with your airline, because it may impose stricter conditions.
