Yes, power banks are generally permitted through security in carry-on baggage, and most airlines follow an international rule allowing up to 100 watt-hours without special approval. Larger capacities, typically 100-160 Wh, often need prior airline approval, and anything above that is commonly barred from flights entirely.
The detail that catches travelers out is that power banks are labeled in milliamp-hours (mAh), not watt-hours — the figure airlines actually regulate. Converting roughly follows mAh × voltage ÷ 1000, with most power banks near 3.7V, so a 20,000 mAh power bank works out to around 74 Wh, still under the common limit, while a 30,000 mAh unit can approach or exceed it depending on the exact voltage.
This is a safety regulation rather than a guideline, and it’s checked at security — carrying documentation of the watt-hour rating, often printed on the device itself, helps if questioned at the checkpoint.
Check with your airline and read the label before you follow anything here. Lithium battery watt-hour limits, liquids allowances and lock policies differ by carrier and by country, and change over time — the figures published by the airline or security authority you are actually traveling with take precedence over anything written on this site. A power bank or spare battery is carried exactly as its manufacturer and your airline specify, never estimated. We report what is published — a watt-hour rating, a size limit, a lock's official recognition — and this site describes the equipment only: nothing here is a guarantee about what a specific checkpoint will allow on a specific day.
Last reviewed 26 August 2026