Few things are more useful while travelling than a power bank. Boarding passes live on our phones, maps guide us through unfamiliar cities, headphones run for hours, and a long travel day can drain a battery well before you reach your destination.
That makes a portable charger an obvious thing to pack.
But because power banks contain lithium-ion batteries, they are also subject to aviation safety rules. The important part is not whether you can take one with you — in most cases, you can. It is knowing where to pack it and how large it is allowed to be.
Here is what you need to know before heading to the airport.
Can you take a power bank on a plane?
Yes. Most everyday power banks can be taken on passenger flights.
The key rule is simple: a power bank belongs in your carry-on baggage, not in your checked suitcase.
Aviation authorities treat power banks as spare lithium batteries because their primary purpose is to store energy and supply it to another device. Spare lithium batteries are kept in the aircraft cabin so that any unusual heat, smoke or battery failure can be noticed and dealt with quickly.
If your cabin bag is taken from you at the gate and placed in the hold, remove the power bank first and keep it with you in the cabin.
For most travellers, that is the single most important rule to remember.
Why watt-hours matter more than mAh
Power banks are usually marketed by capacity in milliampere-hours: 5,000 mAh, 10,000 mAh, 20,000 mAh and so on.
Airline regulations, however, are generally based on watt-hours — Wh.
For lithium-ion batteries up to 100 Wh, carriage in hand luggage is generally permitted without special airline approval.
Batteries between 101 and 160 Wh may be permitted, but normally require approval from the airline. Larger spare lithium-ion batteries above 160 Wh are generally not allowed on passenger aircraft.
This means the number you need to look for before flying is not simply “10,000 mAh”.
It is the Wh rating.
Most reputable power banks print this directly on the product or its regulatory label.
If the watt-hour rating is not shown, it can be calculated:
Wh = Ah × V
Because power banks are normally labelled in mAh, divide that number by 1,000 first.
For example, a 5,000 mAh battery rated at a nominal 3.7 V contains approximately 18.5 Wh of energy.
A 10,000 mAh battery at the same nominal voltage is approximately 37 Wh.
Both are comfortably below the common 100 Wh threshold.
The exact figure depends on the battery voltage, so whenever possible, use the Wh value printed by the manufacturer rather than estimating it yourself.
What does 100 Wh mean in practice?
For normal smartphone charging, 100 Wh is a surprisingly generous limit.
Compact 5,000 mAh magnetic power banks sit far below it. So do most conventional 10,000 mAh and many 20,000 mAh portable chargers.
The products that require more attention are very large battery packs designed for laptops, cameras, drones or extended off-grid use.
That is why most people travelling with an everyday phone power bank will never come close to the limit.
Still, checking the label before travelling takes a few seconds and removes the uncertainty.
Why can’t a power bank go in checked luggage?
Lithium-ion batteries store a significant amount of energy in a small space.
Under normal conditions, that is exactly what makes them useful.
If a cell is damaged, defective, overheated or short-circuited, however, it can enter a process known as thermal runaway. The battery can heat rapidly and, in rare cases, produce smoke or fire.
Inside the cabin, crew members can identify and respond to a problem.
Inside the cargo hold, that becomes considerably more difficult.
This is why aviation rules distinguish between many electronic devices with batteries installed inside them and spare batteries such as power banks.
Your power bank should stay with you.
What if your power bank is damaged?
Do not travel with a swollen, damaged or recalled power bank.
A battery that has changed shape, shows physical damage, becomes unusually hot or has been subject to a safety recall should no longer be treated like a normal portable charger.
Battery safety matters more than saving the cost of replacing the product.
The same principle applies outside aviation: a battery is not a component worth taking chances with.
Can you use a power bank during the flight?
This is where the answer becomes more dependent on the airline.
Carrying a power bank and using one during the flight are not necessarily governed by exactly the same policy.
Some airlines allow portable chargers to be used normally in the cabin, while others impose additional restrictions on charging, storage or where the battery must be kept during the flight.
Airline policies have also become more specific in recent years.
Before travelling, particularly on a long-haul or international flight, check the policy of the airline you are actually flying with.
The general aviation rules tell you whether the battery can travel.
The airline determines whether it imposes additional conditions.
What should you check before leaving for the airport?
For a normal portable power bank, the process should be straightforward.
Check the Wh rating printed on the device. Make sure the battery is undamaged. Pack it in your carry-on rather than your checked baggage. Protect it from anything that could damage it or accidentally short its electrical contacts.
And if the power bank approaches or exceeds 100 Wh, check directly with the airline before travelling.
There is little reason to make it more complicated than that.
Travel is exactly where compact charging makes sense
The rules around batteries also illustrate something interesting about portable charging.
For most travellers, the challenge is not carrying the maximum amount of energy physically possible.
It is carrying enough.
Enough to use navigation after landing.
Enough to keep a boarding pass available after a delayed flight.
Enough to listen to music through a train connection.
Enough to arrive without spending the last two hours looking for a wall socket.
A large battery can provide more energy, but it also means more weight and more space taken up in a bag.
For everyday travel, portability often matters just as much as capacity.
That is one reason we chose 5,000 mAh for Snap.
It sits comfortably below the common airline battery limits while providing the kind of additional energy a phone typically needs during a long day away from a charger.
More importantly, it is designed to be something you actually want to take with you.
Because the most useful power bank at the airport is not the one with the largest number printed on it.
It is the one in your pocket.
Explore Snap.