Power bank on a plane: which limit applies?

The basic rule: watt-hours instead of mAh

Lithium-ion batteries are subject to the IATA dangerous goods regulations worldwide. For power banks three simple limits apply, measured in watt-hours (Wh), not in milliamp-hours (mAh):

• Up to 100 Wh: allowed in hand luggage without approval. This covers practically all common power banks up to about 27,000 mAh.
• 100 to 160 Wh: only with prior approval from the airline, usually a maximum of two per person.
• Over 160 Wh: generally prohibited on passenger flights.

In addition, without exception: power banks belong always in hand luggage, never in checked luggage. In the hold a battery fire would go unnoticed, whereas in the cabin the crew can intervene.

Converting mAh to Wh: the formula

On most power banks the capacity is stated in mAh, but the flight limit is defined in Wh. The conversion:

Watt-hours = (mAh ÷ 1,000) × cell voltage

The cell voltage of lithium-ion batteries is 3.7 volts (not the 5 V of the USB output, which is the most common calculation error). Example for a 20,000 mAh power bank:

(20,000 ÷ 1,000) × 3.7 = 74 Wh, so clearly under the 100 Wh limit.

For orientation, the common capacities:

• 10,000 mAh ≈ 37 Wh: no problem
• 20,000 mAh ≈ 74 Wh: no problem
• 25,000 mAh ≈ 92.5 Wh: no problem (just under the limit)
• 27,000 mAh ≈ 100 Wh: exactly at the limit
• 30,000 mAh ≈ 111 Wh: only with airline approval
• 50,000 mAh ≈ 185 Wh: prohibited on planes

Good manufacturers print the Wh figure directly on the casing, so you don't have to calculate at the gate. If it is missing, the formula above helps.

These XL power banks can come along

In practice that means: even the big 100-watt laptop power banks with 20,000 to 25,000 mAh stay under 100 Wh and are fine for flying. Three examples from our XL power bank comparison:

• INIU P63-E1 (25,000 mAh) → 92.5 Wh ✓ allowed
• Anker 737 PowerCore (24,000 mAh) → 86.4 Wh ✓ allowed
• Baseus Blade 100W (20,000 mAh) → 74 Wh ✓ allowed

All three also charge laptops with up to 100 W and stay suitable for hand luggage. The direct comparison of the two capacity giants is shown in the head-to-head INIU P63 vs Baseus Blade 100W; if you are torn between Anker and UGREEN, the answer is in the head-to-head Anker 737 vs UGREEN Nexode 145W.

Practical tips for boarding

• Keep the Wh figure visible: if it is on the casing, there is no discussion at security.
• Protect the contacts: stow loose power banks so the connectors cannot short-circuit, ideally in the original packaging or a pouch.
• Not in the suitcase: if the power bank is found in checked luggage, the suitcase can be pulled aside.
• Several devices: several power banks under 100 Wh are generally allowed as long as they are intended for personal use.

If in doubt, the rules of the airline in question always apply, but the 100 Wh limit is the same internationally and covers almost all household power banks.

Verdict

What matters is the watt-hour figure: up to 100 Wh is free in hand luggage, above that only with approval. The formula (mAh ÷ 1,000) × 3.7 quickly converts any capacity. Most 20,000 to 25,000 mAh power banks land at 74 to 92.5 Wh and can come along without any problem. Which XL models are worthwhile for travel and laptops is in the power bank comparison.

Frequently asked questions

How many watt hours of power bank are allowed on a plane?

Up to 100 Wh is allowed in hand luggage without approval, 100 to 160 Wh only with airline approval (usually max. two), and over 160 Wh is prohibited. Power banks must never go in checked luggage.

How do I convert mAh to watt-hours?

Watt-hours = (mAh ÷ 1,000) × 3.7 volts. A 20,000 mAh power bank therefore has 74 Wh, a 25,000 mAh power bank 92.5 Wh: both under the 100 Wh limit and so allowed.

Can the power bank go in checked luggage?

No. Power banks and lithium batteries must always go in hand luggage and must not be transported in checked luggage, because in the hold a battery fire would go unnoticed.