Power Banks and Air Travel

Spare lithium batteries are the one thing in your bag with real rules attached, and they are the same almost everywhere.

Carry-on only, always

A spare lithium battery or power bank must travel in the cabin. It cannot go in checked luggage, on any airline, anywhere. The reason is simple: a fire in the cabin can be dealt with, and a fire in the hold cannot.

This applies to the power bank itself, not to a device with a battery inside it. A laptop can be checked; the power bank in the same bag cannot.

The number that matters is watt-hours

Airlines limit spare batteries by energy, in watt-hours (Wh), not by capacity in milliamp-hours (mAh). The conversion is:

Wh = (mAh / 1000) x voltage

Most power banks run at 3.6 or 3.7 volts, so a 20,000 mAh bank is about 74 Wh.

• Under 100 Wh travels freely in carry-on. This covers nearly every consumer

power bank, including large ones.

• 100 to 160 Wh usually needs airline approval in advance, and most carriers

limit you to two.

• Over 160 Wh is not allowed on a passenger aircraft at all.

Look for the marking

The rating is printed on the body of the bank. If a power bank has no visible Wh or mAh marking, security is entitled to refuse it, and often will.

Practical advice

• Keep it where you can reach it. Some airlines ask you to keep spare batteries

accessible rather than in an overhead locker.

• Tape or cap exposed terminals so nothing can short across them in a bag.
• Charging a device from a power bank in flight is fine on most airlines;

charging the bank itself from a seat outlet is often not.

• Buy the capacity you need. A bigger bank is heavier every day of the trip for a

benefit you use on one of them.