Checked October 2, 2026 against the FAA, Singapore Changi Airport and the Korean Air newsroom. We have not tested any power bank on a flight; this checklist is built only from those published rules.
Shopping for a travel power bank usually starts with the mAh number or the charging wattage. But "can I bring it on the plane?" and "can I use it during the flight?" are two different questions, and neither is answered by capacity alone. Check three things before you pay.
1. Read the Wh rating on the label
The FAA says a lithium-ion battery’s Wh should be marked on the battery; if it isn’t, multiply the volts (V) by the amp hours (Ah). For mAh, divide by 1000 to get Ah, then multiply by the volts.
- Worked example (not a specific product): 20,000mAh at a rated 3.7V → 20,000 ÷ 1000 × 3.7 = 74Wh
Use the battery’s rated voltage. A charging output such as 140W describes how fast it can deliver power, not how much energy it stores in Wh. Look for the Wh figure, or the rated voltage and capacity, in the listing or product photos before buying. The math only tells you how to read the numbers; it does not mean a given product is approved for any flight.
2. Carriage: Wh bands plus airline and departure-airport rules
Under the FAA’s guidance for flights in the US (based on US DOT rules), spare lithium batteries, including power banks, must be carried on and cannot be checked, and must be protected from damage and short circuit. Lithium-ion batteries are limited to 100Wh per battery; with airline approval, passengers may also carry up to two spare larger lithium-ion batteries (101–160Wh).
The FAA also notes that many airlines, US domestic and international, may have stricter quantity and Wh limits, and asks travellers to check with their air carrier before travelling. Departure airports can add their own rules. Changi Airport, for example, says that from 15 April 2026 all passengers departing Changi may carry a maximum of two power banks per person — two in total, regardless of Wh rating. Power banks over 100Wh and up to 160Wh are allowed only with the airline’s approval, and those over 160Wh are not allowed. That rule is specific to flights departing Singapore Changi.
3. In-flight use: allowed on board does not mean usable
The Korean Air newsroom (January 23, 2026) says that from January 26, on domestic and international flights of Korean Air, Asiana Airlines, Jin Air, Air Busan and Air Seoul, charging phones, tablets, laptops, cameras and other devices with a power bank is prohibited. Charging or using power banks on board is banned and passengers may only carry them; storing them in the overhead bin is also prohibited. This covers those five carriers, not every flight.
Changi’s guidance for flights departing Singapore likewise says power banks must not be recharged on board, and advises passengers not to use them to charge devices.
So on those carriers, a bigger bank will not let you charge your phone mid-flight. Sizing it for use after you land may fit your plans better.
Checklist before you pay
- Is Wh printed on the label — or can you calculate it from the rated voltage and mAh?
- What are your airline’s and departure airport’s quantity and Wh limits? (Re-check on the day; on a codeshare, check the operating carrier.)
- Does your airline allow using or recharging power banks on board?
- How will you prevent short circuits, e.g. tape over the terminals or a separate pouch for each bank?
Airline and airport rules change, so re-check your operating airline and departure airport on the day you fly.
Sources (read October 2, 2026): FAA, "Airline Passengers and Batteries" — https://www.faa.gov/hazmat/packsafe/airline-passengers-and-batteries · Changi Airport, "Security & Baggage Restrictions at Changi Airport" — https://www.changiairport.com/en/fly/security-and-baggage-restrictions.html · Korean Air Newsroom (Korean), January 23, 2026 notice on the power bank in-flight use ban by five Hanjin Group airlines — https://news.koreanair.com/%ED%95%9C%EC%A7%84%EA%B7%B8%EB%A3%B9-%EC%86%8C%EC%86%8D-5%EA%B0%9C-%ED%95%AD%EA%B3%B5%EC%82%AC-%EC%98%A4%EB%8A%94-26%EC%9D%BC%EB%B6%80%ED%84%B0-%EB%B3%B4%EC%A1%B0%EB%B0%B0%ED%84%B0%EB%A6%AC/