Power Bank on a Plane: The Rule Is Simpler Than the Panic

You are packing the night before, the power bank is in your hand, and you cannot remember whether it goes in the suitcase or the rucksack.

Search it and you get forum arguments, airline pages that contradict each other, and a number in milliamp hours that nobody explains.

The actual rule fits in two sentences and it comes from the FAA. I have put its own arithmetic below too, because the question people really ask is about milliamp hours.

Carry-on only, and there is no wriggle room

One rule to remember, in the regulator's own words. The TSA puts it from one end: power banks in checked bags, "No." In carry-on, "Yes."

The FAA is plain on its PackSafe lithium battery page: spare batteries "including power banks and cell phone battery charging cases, must be carried in carry-on baggage only."

This is about fire, not security. A battery can overheat, and in the hold nobody can reach it. Never put one in a checked suitcase, even if it has travelled that way before without anyone noticing.

The gate-check trap nobody warns you about

Gate-checking is not carry-on. Your bag goes into the hold, and the rule goes with it. This is the part that catches frequent flyers, and it is written down.

The FAA states it directly: "When a carry-on bag is checked at the gate or at planeside, all spare lithium batteries and power banks must be removed from the bag and kept with the passenger in the aircraft cabin."

On a full flight you will be asked to hand over your cabin bag. That is the moment to open it. Take the power bank out, keep it on you, and pack it where you can reach it in a hurry.

Is 20,000 mAh allowed? Do the FAA's own sum

The number on the box is the wrong unit. The limit is in watt hours, and lithium ion batteries "are limited to a rating of 100 watt hours (Wh) per battery."

The conversion is published. The FAA gives the method: "For milliamp hours (mAh), divide mAh by 1000 (to get to Ah) and then multiply by the V."

Ours, using that method: 20,000 mAh is 20 Ah, and at the 3.7 V a lithium cell actually runs at, that is 74 Wh. Comfortably inside the limit.

Do not multiply by 5. The USB output is 5 V, the cells are not, and using 5 V invents a 100 Wh figure that would scare you for no reason.

Read the bank before you calculate

Simpler, and it is what the regulator tells you to do first. The FAA's first instruction: a battery's "Wh should be marked on the battery; if not, you will need to determine the Wh."

Most modern banks print it, in small type near the capacity, often underneath. The printed figure beats your arithmetic. The maker knows the real cell voltage.

No marking and no way to work it out is a problem at the gate. A bank with nothing legible on it is the one that gets questioned.

Above 100 Wh, and the hard ceiling

Two tiers, and one of them needs permission. Between 101 and 160 Wh you have to ask: with airline approval the FAA allows "up to two spare larger lithium-ion batteries" in that band.

That tier has a count as well as a size. Two per person, not a bagful. Over 160 Wh is simply out, and the FAA lists battery generators as "forbidden on passenger aircraft."

A camping power station usually sits in that band. Check it before the airport, not at it. The same watt hour thinking applies to what charges your laptop.

Damage, terminals, and the quantity question

Terminals must be protected. The FAA's list of acceptable methods includes retail packaging, taping the terminals, a battery case, or "putting them snugly in a plastic bag or protective pouch."

Damaged or recalled batteries are out entirely, in carry-on and checked alike, unless the battery has been removed or made safe.

Ours: a swollen bank is a damaged bank. If the case no longer sits flat, leave it at home. Swelling is the same warning sign on a laptop.

On quantity, the FAA sets no general limit for batteries under 100 Wh, as long as they are for your own use rather than for resale.

Your airline is allowed to be stricter

The FAA says so plainly: many airlines "may have stricter quantity and Wh limits to include how many power banks/portable chargers each passenger is allowed to travel with, regardless of Wh capacity."

Its instruction follows immediately: "Please check with your air carrier for its specific restrictions before traveling." That sentence is what makes every other page's answer incomplete.

Carriers have been adding rules about where a bank may be stowed and whether it may be charged in flight. We could not verify individual airline wording from primary sources for this article, so none is quoted here.

Which is exactly why you check yours. Ten minutes on the airline's baggage page beats an argument at the gate.

**Status: the rules here were read on 18 September 2026 from the FAA PackSafe lithium battery page, last updated 11 August 2026, its airline passengers and batteries page, last updated 10 August 2026, and the TSA power banks entry.

No airline's own policy was quoted, because none could be read from a primary source, and nothing here is a substitute for your carrier's page.**

Can I take a 20,000 mAh power bank on a plane?

Yes. Using the FAA's own conversion, 20,000 mAh divided by 1000 is 20 Ah, and at a lithium cell's 3.7 volts that is 74 watt hours, which is under the 100 Wh limit. It must go in your carry-on, never in a checked bag.

Why can't a power bank go in checked luggage?

Because a lithium battery can overheat without warning, and in the hold nobody can reach it. The FAA requires spare batteries and power banks in carry-on only, and the TSA lists them as not allowed in checked bags.

What happens if my carry-on gets gate-checked?

You have to take the power bank out. The FAA's wording is that when a carry-on bag is checked at the gate or planeside, all spare lithium batteries and power banks must be removed and kept with the passenger in the cabin.

How many power banks can I bring?

The FAA sets no general limit for batteries under 100 Wh as long as they are for your own use. Above that, between 101 and 160 Wh, the limit is two spares per person and you need airline approval. Your airline may cap the number regardless.

The Short Version

• Power banks go in carry-on. Never in a checked bag. That is the FAA rule.
• Gate-checking your cabin bag means taking the power bank out first.
• The limit is 100 Wh per battery, not a figure in mAh.
• Convert with the FAA's method: mAh divided by 1000, then multiplied by the volts.
• A 20,000 mAh bank works out at about 74 Wh, so it is fine.
• Use 3.7 V for the sum, not the 5 V printed on the USB output.
• 101 to 160 Wh needs airline approval and is capped at two per person. Over 160 Wh is forbidden.
• Damaged or swollen banks are not allowed, and terminals must be protected from shorting.

Where to Next

The battery inside the laptop plays by different rules from the spare in your bag, and that difference is worth knowing before you pack either.

Move the power bank out of the suitcase tonight, while you are still at home and it costs nothing. Turn it over and look for a Wh figure printed on it, so you are not doing arithmetic in a queue.

If it is a big one bought for camping, work out its watt hours today and call the airline if it is over 100. And put it somewhere you can reach in seconds, because a gate-check gives you about that long.

If an airline asked you something about a power bank that is not covered here, say which airline and what they asked in the comments. Carrier rules are the part that moves.