You are packing for the holidays and the power bank goes in the bag, as always. Then a friend mentions an airline that confiscates them, another that bans using them, and a new "semi-solid-state" kind that is supposedly safer. Which of that is true for your flight?

The short answer: Yes, you can take it, in your cabin bag only. Keep each one at or under 100 Wh, carry no more than two, and expect to be told not to charge it or use it in flight. Semi-solid-state cells are still lithium-ion, so the same limits apply.

The three numbers that decide it

Airline battery rules run on watt-hours, not mAh. The UK CAA spells out the bands most regulators share: up to 100 Wh needs no approval, 100 to 160 Wh needs airline approval, and no more than two power banks per person. The US TSA is blunt about the other half: carry-on yes, checked bags no.

Power bank capacity bands and what they mean at the gate

Rating on the label	Roughly, at 3.7 V	What happens
Up to 100 Wh	Up to about 27,000 mAh	Allowed in cabin bag, no approval, maximum two
100 to 160 Wh	About 27,000 to 43,000 mAh	Airline approval needed; many airlines now refuse
Over 160 Wh	Above about 43,000 mAh	Not allowed on passenger flights
Any size, checked bag	Any	Prohibited everywhere

The two-bank cap is new. On 27 March 2026 ICAO added an addendum to its Technical Instructions, and IATA's guidance to airlines lists the changes: power banks are now separate from spare batteries, limited to two per person, and must not be recharged on board. IATA also says the 100 to 160 Wh approval route will be dropped from its 2027 rulebook, so treat 100 Wh as the real ceiling.

How to turn mAh into Wh

Most labels print both. If yours shows only mAh, the CAA formula is amp-hours times voltage: divide mAh by 1,000, then multiply by the nominal voltage printed on the pack. Example: a 20,000 mAh bank at 3.7 V is 20 × 3.7 = 74 Wh, comfortably under the limit.

Try it on the big one. Belkin's UltraCharge 22K, a 22,000 mAh laptop bank due in November, works out to about 81 Wh at 3.7 V, so it flies. A 30,000 mAh bank at 3.7 V is 111 Wh and lands in the approval band that airlines are closing. Use the voltage on your label; a 3.85 V cell pushes the numbers up slightly.

Can you use it in flight?

Increasingly, no. Emirates allows one power bank under 100 Wh per passenger since 1 October 2025, bans any use on board, bans charging it from the seat, and wants it in the seat pocket or under the seat, never the overhead bin. Every bank must also show its capacity rating.

Singapore Airlines and Scoot stopped in-flight use in April 2025, and from 15 April 2026 the Civil Aviation Authority of Singapore limits anyone departing Singapore to two power banks; extras are disposed of at the airport. Executive Traveller notes the old limit was 20.

In India the DGCA circular reported by WION in January 2026 bans using or charging power banks in flight, keeps them in hand baggage and out of overhead bins, and followed an IndiGo power bank fire at Delhi in October 2025. IndiGo and Air India added boarding reminders, per The Logical Indian. In October 2026 the DGCA went further and banned one specific model, the MOBIKINS MK-PB-04, after another IndiGo flight diverted to Hyderabad.

The US is tightening too. Southwest limits passengers to one charger of 100 Wh or less from 20 April 2026, bars it from overhead bins and in-seat recharging, and still lets you use it if it stays visible, per Fox Business. The Associated Press reports the FAA logged 97 lithium battery incidents in 2025. Rules vary, so read your airline's page.

Are semi-solid-state power banks safer?

Belkin's September press release for its UltraCharge Pro line claims the cells help "reduce the risk of thermal runaway, fire, and swelling" and last up to three times longer, defined as keeping 80% capacity after 1,000 cycles. Those are the maker's claims, not independent test results. TNW explains the design adds a gel layer beside the liquid electrolyte; it is not fully solid-state.

Two practical points. First, Chargie notes a semi-solid pack follows "the exact same Wh math and thresholds" as any other, so it buys no exemption at the gate. Second, these cells are still lithium-ion and still age when parked at full charge, the same lesson as charging your phone to 80%. The capacity race itself is covered in the silicon-carbon battery explainer.

Pre-flight checklist

1. Find the Wh on the label. No label or no rating? Leave it at home; Emirates and others refuse unmarked banks.
2. Confirm it is 100 Wh or less. If only mAh is shown, do the division above.
3. Take two at most, one on Southwest or Emirates.
4. Put it in your cabin bag with the ports covered or in a pouch, never in checked luggage, even if your bag is gate-checked.
5. Charge your phone before boarding and plan on not using the bank in the air; keep it in the seat pocket, not the overhead bin.
6. If it gets hot, smells or swells, tell the crew immediately.

Frequently asked questions

Does the two-bank limit count my camera or laptop batteries?

No. CAAS told Executive Traveller that a rechargeable battery in a device is not a power bank, and IATA's guidance separates power banks from spare batteries. Spares keep their own rules.

Can I charge my phone from the seat USB port instead?

Yes. The bans target recharging the power bank and using it to charge devices. The aircraft's own outlets are fine, which is why Emirates and Southwest point passengers to in-seat power.

So pack one good bank under 100 Wh, label visible, in the cabin bag, and treat it as a ground tool this winter. The plane's USB port does the rest.