Yes, a 27,000 mAh power bank is allowed on flights — but it is a borderline case that requires some awareness. At 3.7V, 27,000 mAh equals 99.9 Wh, which is technically under the universal 100 Wh carry-on threshold. However, its proximity to the limit means you may occasionally be questioned by security staff, especially at Chinese and Indian airports.
The Calculation
99.9 Wh is under the 100 Wh limit, so no airline approval is needed. The IATA standard is clear: under 100 Wh means no approval required.
However, some important caveats apply:
- If your power bank's label shows the Wh value directly, use that. A 27,000 mAh device labelled as "100 Wh" is technically at the limit, not under it, and some airlines may require approval for devices labelled exactly at 100 Wh.
- If the label shows only mAh, the 3.7V calculation applies and you get 99.9 Wh — under the limit.
Why 27,000 mAh Is a Popular Travel Size
Many frequent travellers deliberately choose power banks in the 25,000–27,000 mAh range because they offer near-maximum allowed capacity while staying clearly under the 100 Wh limit. This gives you:
- Approximately 5–6 full charges of a modern smartphone
- Approximately 2 full charges of a recent laptop
- Multiple charges of wireless earbuds, smart watches, and tablets
Popular models in this range include the Anker PowerCore 26800 (26,800 mAh, 99.2 Wh) and various Baseus and Xiaomi models in the 25,000–27,000 mAh range.
How to Handle a Borderline Security Check
If a security officer questions your 27,000 mAh power bank, here is what to do:
- Stay calm. This is a routine verification, not a confiscation.
- Show the label. Point to the mAh figure (27,000) and explain the calculation: 27,000 × 3.7 ÷ 1,000 = 99.9 Wh, under the 100 Wh limit.
- Carry a screenshot. A screenshot of the product specification page showing mAh and Wh values is helpful at airports where staff may be unfamiliar with the calculation.
- Know the IATA rule. Under 100 Wh = no approval required under IATA DGR guidelines, which virtually every airline and aviation authority references.
- Use our tool. The Power Bank Check calculator at powerbankcheck.com shows the result with a shareable URL — useful to show staff on your phone.
What the Recent Rule Changes Mean for 27,000 mAh
The new in-flight use bans introduced in 2025 and 2026 do not affect whether you can carry a 27,000 mAh power bank — they only affect what you can do with it during the flight on certain airlines:
- Lufthansa, Swiss, Austrian (Jan 2026): Carry allowed, in-flight use banned. Lufthansa announcement
- Singapore Airlines (Apr 2025): Carry allowed, in-flight use banned. SIA advisory
- All other airlines: Standard IATA rules apply. 27,000 mAh is allowed in carry-on, no approval needed.
Bottom line: A 27,000 mAh power bank is allowed on flights worldwide. At 99.9 Wh it is under the limit on every airline. Be prepared to explain the calculation if asked, especially on flights through China, India, or South Korea.
Sources: IATA Lithium Battery Guidance · FAA Pack Safe