In brief
- Power banks must go in carry-on bags, not checked luggage.
- Under US rules, batteries up to 100 watt-hours are allowed without airline approval.
- Convert milliamp-hours to watt-hours to check a power bank against airline limits.
- Some airlines restrict using or charging power banks during flights, so check before you fly.
Navigation, photos, tickets and translation all run through your phone on a trip, and batteries drain fast. A power bank solves that, but airlines treat them carefully because they contain lithium batteries. Here’s how to choose one and fly with it.
Choosing a capacity
| Rated capacity | Roughly suits | Watt-hours at 3.7 volts |
|---|---|---|
| 5,000 mAh | One phone top-up, very light | About 18.5 Wh |
| 10,000 mAh | One to two phone charges | About 37 Wh |
| 20,000 mAh | Several phone charges or a tablet | About 74 Wh |
| 25,000 mAh and up | Laptops and long trips | About 92 Wh and up |
Real-world output is lower than the rated capacity, because some energy is lost in conversion.
Airline rules in the US
- Carry-on only: spare lithium batteries, including power banks, aren’t allowed in checked bags.
- Up to 100 Wh: allowed without airline approval.
- 101 to 160 Wh: need airline approval, with a limit of two spare batteries per passenger.
- Over 160 Wh: not allowed on passenger aircraft.
Check the FAA’s guidance and your airline’s own rules, since airlines can be stricter, especially on international flights.
Caution: Some airlines don’t allow passengers to use or charge power banks during the flight, and some require them to be kept within reach rather than in an overhead bin. Read your airline’s battery policy before you fly.
At airport security
- Keep the power bank in an easy-to-reach pocket of your carry-on; you may be asked to take it out.
- Make sure the capacity label is readable. Unlabeled batteries can be refused.
- Don’t fly with a power bank that is swollen, damaged or overheating. Recycle it properly instead.
- If your carry-on is taken for gate check, remove the power bank and keep it with you.
Smart charging habits
- Charge overnight at your lodging, including the power bank itself.
- Use a good cable. A fast-charging cable and a compatible power bank charge much faster.
- Save battery by lowering screen brightness and downloading maps for offline use.
- Keep it cool. Don’t leave power banks in hot cars or direct sun.
Try this: Check the label before you buy. A power bank that shows its capacity in watt-hours as well as mAh makes airport checks easier.
What to look for
- Capacity printed clearly on the case, ideally in both mAh and Wh.
- USB-C with fast charging support for modern phones.
- A built-in cable or pass-through charging if you want fewer things to carry.
- A size and weight that suit your daypack.
The bottom line
Pick a capacity that matches your days, keep power banks in your carry-on, stay at or below 100 Wh to avoid approval hassles and check your airline’s rules for in-flight use. Our plug adapter guide covers charging gear for the outlets at your destination, and our list of travel apps worth setting up shows how offline content saves battery.
FAQ
Can I bring a power bank on a plane?
Yes, in your carry-on bag. Under US rules, spare lithium batteries, including power banks, aren’t allowed in checked baggage. Check your airline’s policy too.
How do I calculate watt-hours?
Multiply the capacity in milliamp-hours by the voltage and divide by 1,000. A 20,000 mAh power bank at 3.7 volts works out to about 74 watt-hours.
What size power bank do I need?
For a day of sightseeing, a capacity that recharges your phone once or twice is usually enough. Larger banks suit long trips, laptops or camping.
Can I use my power bank during the flight?
It depends on the airline. Some have restricted using power banks on board, so check your airline’s rules before you fly.