TSA & Airline Power Bank Rules: Capacity, Wh & Battery Limits

Power Bank, Portable Charger & Spare Battery: What’s the Difference?

In everyday language, “power bank” and “portable charger” mean the same thing: a rechargeable pack containing a lithium-ion or lithium-polymer battery that you use to recharge a phone, tablet, headphones or camera away from an outlet. In aviation language, that pack is a spare (uninstalled) lithium battery, and that classification is what drives the rules — not the fact that it looks like an accessory.

• Power bank / portable charger: contains its own battery. Treated as a spare lithium battery. Carry-on only.
• Wall charger / plug adapter: no battery inside. Not a spare battery, and not subject to watt-hour limits. See our guides on bringing a charger and phone chargers specifically.
• Charging cable: passive accessory, no battery, no capacity rules.
• Device with an installed battery (laptop, phone, camera): different category. Installed batteries have more permissive packing rules than spares, though airlines still prefer them in the cabin. Broader context in our TSA rules for electronics guide.

Power Bank Watt-Hour (Wh) Rules Explained

A watt-hour measures energy: how much power a battery can deliver, multiplied by how long it can deliver it. One watt-hour is one watt sustained for one hour. Aviation regulators chose this unit deliberately. When a lithium cell fails and enters thermal runaway, the severity of the event tracks the total stored energy, not the charge capacity in isolation. A pack rated at 74 Wh and a pack rated at 160 Wh present meaningfully different hazards even if their mAh numbers look similar on paper.

Milliamp-hours alone cannot answer the question, because mAh describes charge moved at some voltage that the number itself does not state. Two packs both labelled 20,000 mAh can carry different energy if one is built from cells at a nominal 3.7V and the other operates at a higher pack voltage. Energy is the product of both figures, which is why the regulated limit is written in Wh and why manufacturers who sell to travelers print the Wh rating on the case.

Under current FAA guidance for passengers, spare lithium-ion batteries are treated in three capacity bands: 100 Wh or less, carried in the cabin without operator approval; above 100 Wh up to 160 Wh, permitted only with airline approval and generally limited to two spares per passenger; and above 160 Wh, forbidden in passenger baggage altogether. Those thresholds come from aviation safety rules administered by the FAA. TSA’s role is different: it screens what you bring to the checkpoint and enforces that spare batteries are in carry-on rather than checked bags. When people say “the TSA power bank rule,” they are usually describing an FAA capacity limit being applied at a TSA checkpoint.

Convert Your Power Bank’s Capacity

If your power bank shows mAh but not Wh, convert it here. The result is an estimate based on the voltage you enter.

Common Power Bank Sizes in Watt-Hours

Examples below assume a nominal battery voltage of 3.7V. Check the actual voltage and Wh rating printed on your power bank — the same mAh figure can convert differently on a different pack.

These are educational conversions, not product endorsements. TSA does not certify or approve consumer power banks, so no model can accurately be described as “TSA approved.”

How to Find the Wh Rating on Your Power Bank

• The printed label on the back or bottom of the casing, often in small type near the model number and certification marks.
• The same label usually lists mAh capacity and a nominal voltage such as 3.6V or 3.7V, which is what you need if Wh is absent.
• The manufacturer’s specification page or retail listing for your exact model number.
• The printed manual, quick-start card, or packaging that came with the unit.

When the manufacturer has printed a Wh rating, treat that figure as authoritative and prefer it over anything you calculate. A calculated value relies on the voltage you assumed; the printed value reflects the pack as built and is what an airline or screening officer will read. Photographing the label before you travel makes the number easy to produce if you are asked.

Why Power Banks Belong in Carry-On Baggage

FAA guidance directs that spare lithium batteries travel in the passenger cabin. The reasoning is response capability: a battery that begins overheating in the cabin is visible, and the crew is trained and equipped to deal with it immediately. The same event in a cargo compartment develops unobserved. That single consideration explains most of the difference between how installed batteries and spare batteries are regulated.

Practically, that means the power bank goes in your carry-on bag, personal item, or pocket — somewhere you keep with you through the flight. If you only need that packing answer and nothing more, our fast answer page on bringing a power bank on a plane covers it directly.

Power Banks in Checked Baggage

The situation that catches travelers out is the gate-check. When a flight is full and your roller bag is taken at the boarding door, or when a small aircraft requires valet checking at the jet bridge, that bag is going into the hold. Before you hand it over, open it and take out any power bank, spare camera battery or loose lithium cell and keep them with you in the cabin. Doing this while you repack at the gate is far easier than being called back after your bag has been screened.

Batteries installed in a device are treated differently from spares. For the full picture across battery types — alkaline, lithium metal, rechargeable and installed — see bringing batteries on a plane.

When Do You Need Airline Approval?

Approval is granted by the airline, not by TSA, and it is not something you can arrange at the checkpoint. If your battery falls in the 100-160 Wh band, contact the carrier before your travel date and follow whatever process it specifies — some handle it by phone, others through a dangerous-goods desk or at check-in. Allow time; this is not always a same-day answer.

What About Very Large Power Banks?

High-capacity packs marketed for laptops, camping or portable power stations frequently exceed 160 Wh, and some exceed it by a wide margin. Once a spare lithium-ion battery is rated above 160 Wh, it falls outside what passengers may carry in either cabin or checked baggage. Airline approval does not extend to that range — approval is a mechanism defined for the 100-160 Wh band, not a general waiver, and no counter agent can authorize a battery the rules place outside passenger baggage entirely.

Larger units generally move as cargo under dangerous-goods shipping rules, which is a separate regulatory regime with its own packaging, labelling and documentation requirements handled by a shipper. If you need that much power at your destination, renting or buying locally is usually far simpler than attempting to fly with the battery.

How Many Power Banks Can You Bring?

There is no single number that applies to every traveler, and any page that gives you one is oversimplifying. For spare batteries at or below 100 Wh, FAA guidance frames the allowance in terms of personal use rather than a fixed universal count, and airlines are free to set their own quantity limits. For batteries in the 100-160 Wh band, the general limit is two spares per passenger, with airline approval.

In practice, a traveler carrying one or two ordinary chargers is unremarkable. A traveler carrying a bag of a dozen batteries — photographers, film crews, drone operators and resellers routinely do — should confirm the allowance with the airline in advance, because quantity is exactly the kind of thing carriers cap and the kind of thing that draws attention at screening.

How Should Spare Batteries Be Packed?

The core requirement for spare batteries is protection against short circuit. A short happens when the terminals bridge across something conductive — loose keys, coins, another battery — releasing energy fast enough to generate heat. FAA guidance for passengers asks that spare batteries be protected from short circuit and from damage, and offers practical ways to do that:

• Keep the battery in its original retail packaging where you still have it.
• Otherwise place each spare battery in a separate plastic bag or protective pouch.
• Tape over exposed terminals on batteries that have them, so nothing can bridge the contacts.
• Pack batteries so they cannot be crushed, punctured or pressed by heavy items in the bag.
• Keep them where you can reach them, in case a screening officer or crew member asks to see the rating.

Damaged or Swollen Power Banks

Swelling means the cell is generating gas internally and has already failed. Do not attempt to discharge, open, puncture, compress or repair it, and do not put it in household rubbish or ordinary recycling. Take it to a battery recycling drop-off or household hazardous waste facility that accepts damaged lithium batteries, and tell them it is damaged so it is handled correctly.

Recalls matter too. Several power bank models have been recalled over fire risk, and a recalled unit should be removed from service and returned or disposed of under the manufacturer’s recall instructions rather than carried onto a plane. Check the model number against the manufacturer’s recall notices if your unit has been in a bag for years without a look.

Can You Use a Power Bank During a Flight?

Two different rule sets are at work here and they answer different questions.

Do not assume that permission to carry equals permission to use. Some airlines now ask passengers to keep power banks within sight rather than in an overhead bin, and some prohibit charging from or into a power bank in the air. These policies are published on carrier dangerous-goods pages and repeated in the pre-departure briefing. Follow the crew’s instructions on the flight you are actually on.

Power Bank Rules on International Flights

• TSA — U.S. security screening. Applies at U.S. checkpoints, not abroad.
• FAA — U.S. aviation safety and hazardous materials rules, including the watt-hour bands described above.
• Your airline — carrier-specific requirements that can be stricter than the regulatory minimum, and that apply for the whole flight.
• Foreign aviation authorities — the regulator of the country you depart from or transit through may impose additional conditions.

The 100 Wh and 160 Wh figures come from internationally harmonized dangerous goods provisions and are widely mirrored, which is why the same numbers appear in many countries. That harmony does not extend to quantity limits, approval procedures, in-flight use or how strictly any of it is enforced. Treat U.S. rules as the baseline for the U.S. portion of your itinerary and check the operating carrier for everything else — on a return leg from abroad, the local authority and the foreign carrier govern, not TSA.

Why You Should Check Your Airline

Rather than trust a third-party list that ages badly, spend two minutes on your carrier’s own dangerous goods or restricted items page and confirm these six points:

• Capacity restrictions, and whether the carrier states a lower cap than the regulatory band.
• Approval requirements and the process for batteries in the 100-160 Wh range.
• Quantity restrictions on how many spare batteries you may carry.
• Onboard use — whether power banks may be used at all during the flight.
• Charging restrictions, including recharging the power bank from a seat outlet.
• International requirements on the specific route you are flying.

mAh vs Wh: What’s the Difference?

mAh (milliamp-hours) describes charge capacity: how much electrical charge the cells can store and deliver. It is the number manufacturers print largest, because it is the one shoppers compare. Wh (watt-hours) describes energy, and it accounts for voltage as well as charge. Because energy is what determines how much heat a failing battery can release, watt-hours is the measurement aviation rules are written around.

Wh = (mAh × V) ÷ 1000

If you know two of the three values you can find the third, which is what the calculator above does. What you cannot do is judge compliance from mAh alone.

Example Calculations

Each figure above depends entirely on the 3.7V assumption. Your pack may be built differently, so check the manufacturer’s specifications and use the printed Wh rating whenever one exists.

Common Power Bank Travel Mistakes

• Packing a power bank in checked baggage, including a bag that gets gate-checked at the last minute.
• Looking only at the mAh figure printed on the front of the package.
• Ignoring voltage, which is half of the watt-hour calculation.
• Not checking the Wh rating the manufacturer already printed on the casing.
• Assuming every airline applies identical quantity and in-flight use policies.
• Traveling with a damaged, swollen or recalled battery.
• Assuming TSA rules apply worldwide on an international itinerary.
• Assuming "airline approval" makes any battery capacity acceptable — above 160 Wh it does not.
• Confusing a wall charger or cable with a power bank; only the battery is a spare lithium battery.

Check Your Power Bank Before Flying

1. 1Find the Wh rating printed on the power bank.
2. 2If Wh isn't printed, find the mAh capacity and the nominal voltage.
3. 3Calculate Wh with (mAh x V) / 1000 using the calculator above.
4. 4Compare the figure with current FAA/TSA aviation rules.
5. 5Determine whether the 100-160 Wh airline approval band applies.
6. 6Check your airline for capacity, quantity, in-flight use and charging rules.
7. 7Pack it in your carry-on, terminals protected, according to current rules.

Frequently Asked Questions