Updated for ICAO specifications effective 27 March 2026
Airlines do not care about milliamp hours. They care about watt hours, and most manufacturers do not print that figure on the box. Work out yours below.
Up to 100 Wh. This is the band almost every traveller is in.
Cell voltage is not the 5 V your phone sees. Most lithium-ion packs sit between 3.6 and 3.85 V; below 3.5 V you are looking at LiFePO4, where a large mAh figure means less energy than it looks.
0–200 Wh
Under 100 Wh: carry-on, no questions.
100 to 160 Wh: ask your airline first, two units maximum.
Over 160 Wh: it stays at home.
The marker follows the calculator above. Note how little headroom the 100 Wh threshold leaves: a 27,650 mAh pack at 3.7 V is already over it.
Example
99.75Wh
Anker Prime Power Bank (26K, 300W)
The Anker Prime Power Bank (26K, 300W) is rated 26,250 mAh at 99.75 Wh. That is 0.25 Wh below the threshold, which is not an accident. It is the largest capacity in this catalogue you can carry without asking anyone.
Priced offer not yet confirmed for this listing.
Compare all power banks →Every power bank below carries a manufacturer-stated Wh figure, cross-checked where a second source exists. Sorted lowest to highest energy.
Catalogue data is temporarily unavailable.
IATA passenger guidance now says travellers should carry no more than two power banks.
Spare batteries are not accepted in the hold. If your bag is gate checked, take the power bank out first.
The updated guidance prohibits recharging a power bank during the flight.
Keep it accessible, in the seat pocket or the bag in front of you, so a fault can be reached.
The ICAO figures are a floor, not a ceiling. Individual airlines and national regulators impose stricter rules, and they are the ones at the gate.
One power bank only, under 100 Wh, and using it on board is not allowed at all. It must stay in the seat pocket or the bag in front of you.
Power banks without a China Compulsory Certification mark are banned outright on domestic flights, regardless of capacity.
A battery whose watt hour rating cannot be determined will not be accepted. If the figure is not printed on the casing, the calculation above will not save you at the desk.
Yes. Two units is the guidance limit, and at roughly 74 Wh each they are both well inside the carry-on band. They go in the cabin, never in the hold.
Look for mAh and a voltage on the casing and use the calculator above. If neither is printed, some carriers, British Airways among them, will simply refuse the battery.
The guidance effective 27 March 2026 prohibits recharging the power bank itself in flight, and several carriers, Emirates included, prohibit using it at all.
It travels in your cabin bag and counts towards its weight. It cannot be checked in, so a gate-checked bag has to be opened first.
At 3.7 V it is 102.3 Wh, so yes, just over. That is the approval band, two units maximum, ask before you reach the desk.
Wall chargers have no cells, so no watt-hour limit applies. This page is about batteries only.