Energizer

Most 10,000 mAh power banks are about 37 Wh at 3.7 V, which is well below the common 100 Wh airline threshold.

A 20,000 mAh power bank is usually about 74 Wh at 3.7 V, so it is normally under the 100 Wh threshold.

27,000 mAh models are often designed to sit just under 100 Wh, but the exact Wh label matters.

A 30,000 mAh power bank is usually about 111 Wh at 3.7 V, which commonly requires airline approval and may be refused on some trips.

Power banks at or below 100 Wh are generally allowed in carry-on baggage without prior airline approval.

Power banks above 100 Wh and up to 160 Wh usually require airline approval and are often limited to two units per passenger.