Best Power Bank for Travel: Two 20000mAh Picks and What Airlines Allow

Every airport has its floor-sitter. Cross-legged beside a pillar, laptop on one knee, cable stretched to the only live socket in the terminal. Meanwhile the good seats by the window sit empty, because none of them have a plug.

The best power bank for travel puts you back in a real chair. It also comes with more rules than almost anything else in your bag, since airlines treat lithium batteries as a fire risk and have tightened their policies over the past couple of years.

This guide covers how much capacity a remote worker needs, whether a power bank can run a laptop, two 20000mAh picks, and the power bank airline rules to check before your next flight.

What size makes the best power bank for travel?

For most people who work on the road, 20,000mAh is the sweet spot. It charges a phone several times over, or keeps a phone, earbuds and a tablet alive through a long travel day. It also stays under the airline limit for carry-on batteries, which we'll get to below.

One thing, though: treat the number on the box with some suspicion. Energy is lost as power moves from the battery into your device, so you receive noticeably less charge than the rating promises. A 20000mAh bank will not hand 20,000mAh to your phone. That's normal. Physics takes its cut.

A 10,000mAh bank is lighter and fine for a day in the city, but it runs dry on a travel day with several devices to feed. Bigger ones get heavy fast, and past a certain size the airlines start to object. For an everyday work bag, 20,000mAh is where convenience and capacity meet — which is why so many lists of the best power bank for travel land on it.

Which 20000mAh power bank should you pack?

At this size, the real differences come down to ports, cables and output. These two come at the problem from opposite directions.

Either one is a fair candidate for the best power bank for travel if your needs are ordinary. If you can't decide, let your cable habits choose for you.

Can a power bank charge your laptop?

Sometimes. The number that decides it is output, measured in watts — not capacity.

Laptops that charge over USB-C rely on a standard called USB Power Delivery, and each one needs a certain wattage to charge properly. Many thin-and-light models are happy with around 45 watts. Larger machines often want 60 to 100 watts. Plug a laptop into a bank that only delivers 20 watts and one of three things tends to happen. It charges at a crawl, it holds steady without gaining much, or it keeps draining while you work, just more slowly.

Three quick checks tell you where you stand:

• Read the wattage printed on your laptop's own charger.
• Find the bank's maximum USB-C output on its listing, which is a separate figure from capacity.
• Confirm the cable between them is rated for that wattage, because a thin cable can quietly throttle a strong bank.

If the numbers don't line up, treat the bank as a charger for your phone and accessories, and plan laptop charging around wall outlets. That's how most people use one on the road anyway, and it works well.

Can you bring a power bank on a plane?

Yes, but only in your carry-on. A power bank is a lithium-ion battery, and under U.S. Federal Aviation Administration rules — as well as those of most airlines worldwide — spare lithium batteries are not allowed in checked luggage because of fire risk. If a bag gets gate-checked at the last minute, take the power bank out first.

What are the power bank airline rules on size?

Airlines count watt-hours (Wh), not milliamp-hours. Under FAA guidance, batteries up to 100Wh can ride in carry-on bags without special approval. Between 100Wh and 160Wh you generally need the airline's permission, and anything larger usually can't fly at all.

To estimate watt-hours, multiply the mAh figure by the battery's voltage and divide by 1,000. Most power banks list a cell voltage around 3.6 to 3.7 volts, which puts a 20,000mAh bank at roughly 72 to 74Wh — comfortably under the limit. Many makers print the Wh rating on the case. Check that yours does, because security staff sometimes ask to see it.

Can you use a power bank during the flight?

Carrying one is a separate question from using one. Since 2025, a growing number of airlines have banned using or charging power banks in the air, and some ask passengers to keep them out of overhead bins so crew can spot a problem sooner. Many carriers also cap how many you can bring, commonly at two. Policies differ by airline and change often, so look up yours before each trip — especially on international routes.

How do you keep a power bank safe?

Keep it out of hot cars and direct sun, and don't leave it charging under a pillow or inside a closed bag. If it swells, smells odd or runs unusually hot while charging, stop using it and recycle it properly. A healthy bank lasts several years of daily travel. A damaged one isn't worth the risk.

The best power bank for travel is also just one of the five pieces in our remote work essentials kit. If you're weighing these two models against each other, our budget vs. premium gear comparison sets them next to the rest of a working traveler's kit.