Power‑bank rules tighten

A power bank is turning into the new airport gotcha: South Korea says that from April 20, 2026, passengers can bring only two, each capped at 160 watt-hours, and neither using one nor charging one will be allowed during the flight. (khan.co.kr) That rule is stricter than the country’s own March 1, 2025 standard, which allowed up to five smaller power banks under 100 watt-hours and still drew a line at two in the 100-to-160 watt-hour range. (korea.kr) The reason airlines care is simple: a loose lithium battery is like a pocket-sized fuel tank with wiring attached, and if it shorts, heats up, or gets crushed, it can start a fire fast enough that crew need to reach it immediately. (icao.int) (iata.org) That is why aviation rules have long pushed spare lithium batteries into the cabin instead of the checked bag: smoke in the seat area can be attacked with water, containment bags, and crew attention, while smoke in the cargo hold is much harder to spot and isolate. (iata.org) The global backdrop changed on March 27, 2026, when the International Civil Aviation Organization issued an addendum that set a new baseline for lithium battery-powered power banks: no more than two per passenger, kept in carry-on baggage, and no recharging in flight. (icao.int) (iata.org) South Korea’s April 20 move looks like a national rollout of that tougher baseline after airlines there had already started tightening their own cabin rules earlier this year. In January 2026, Khan reported that Korean Air and other Hanjin Group carriers were preparing a total ban on in-flight power-bank use. (khan.co.kr 1) (khan.co.kr 2) The watt-hour number is the part most travelers never check, but it is the number security staff and airline agents use because it measures the battery’s total stored energy, not just the marketing label on the box. South Korea’s transport ministry has told passengers to calculate it as milliamp-hours times voltage divided by 1,000. (korea.kr) That means a common 20,000 milliamp-hour pack at 5 volts is about 100 watt-hours, while a larger camping-style battery can cross 160 watt-hours and become a hard no for passenger carriage. South Korea’s 2025 guidance already treated anything above 160 watt-hours as prohibited. (korea.kr 1) (korea.kr 2) Packing method matters too. South Korea’s current safety guidance says terminals should be covered with insulating tape or sealed in a pouch or clear plastic bag, and power banks should stay on the passenger or in the seat pocket, not in the overhead bin. (korea.kr) So the preflight checklist is getting one more line item: count your power banks, find the watt-hour label before you leave home, and assume the operating airline’s dangerous-goods rule will be enforced at the gate, not treated as a suggestion. The International Air Transport Association says its March 2026 guidance was written to help airlines implement the new International Civil Aviation Organization addendum immediately. (iata.org)