According to the guidelines of the IATA, the International Air Transport Association, it is allowed to take a power bank with a maximum of 27,000 mAh or 100W on the plane. Power banks are prohibited in the hold baggage.

Yes, a 27,000 mAh power bank is generally allowed on a flight, but it sits right at the edge of the legal limit. Aviation authorities like the FAA and TSA use Watt-hours (Wh) rather than mAh to determine safety. To calculate this, you use the formula: Wh=(mAh×V)/1000. Most power banks operate at 3.7V, so a 27,000 mAh unit equals approximately 99.9 Wh. This is critical because the standard limit for lithium-ion batteries is 100 Wh per battery. Since 99.9 is just under 100, it is permitted without prior airline approval. However, you must carry it in your hand luggage; it is strictly prohibited in checked bags due to fire risks. Always check the label on your device; if the Wh rating is clearly printed and under 100, you should have no issues at security. If it exceeds 100 Wh (usually around 27,027 mAh or higher), you would need specific airline permission, and they may still cap you at a maximum of two such large batteries per passenger.