What changed
Japan's Ministry of Land, Infrastructure, Transport and Tourism (MLIT) has applied the following rules since April 24, 2026.
- Up to 2 power banks per person may be carried on board (160Wh or less only)
- Do not charge power banks on board
- Do not charge phones or other devices from a power bank on board
This change follows the urgent revision of the international standard by the International Civil Aviation Organization (ICAO) on March 27, 2026.
Source: Japan Ministry of Land, Infrastructure, Transport and Tourism (MLIT): new rules for carrying power banks on board (announced April 14, 2026; applied from April 24, 2026) [in Japanese] (retrieved 2026-09-27)
Source: ICAO (International Civil Aviation Organization): "New power bank restrictions will safeguard international aviation" (March 27, 2026) (retrieved 2026-09-27)
Rules that have not changed
- Do not put them in checked baggage (suitcase). Always carry them on board
- Power banks over 160Wh cannot be carried
- Prevent short circuits: apply insulating tape to the terminals, place them in a case or storage bag, etc.
- Do not place them in overhead compartments. Keep them close to you, e.g. in the seat pocket
According to MLIT, violating the rules on checked baggage, over 160Wh, short-circuit protection, the 2-per-person limit, and not charging power banks on board may be subject to penalties under aviation law. Power banks you could not bring may also not be transportable by air as cargo via courier services.
Source: MLIT: "To All Passengers: Regarding Bringing Power Banks on Board" (English version) (retrieved 2026-09-27)
Calculating Wh (watt-hours)
Many power banks show mAh (rated capacity) and V (rated voltage). Wh is calculated as follows.
Wh = rated capacity (mAh) × rated voltage (V) ÷ 1,000
In MLIT's example, 27,000mAh at 3.7V is 99.9Wh. If the product shows Wh, use that number.
The USB output (OUTPUT) of 5V is a different number from the rated voltage. Calculating with 5V gives a value that is too large. If you cannot find the rated voltage or Wh, ask your airline.
How to count them
| Power banks | Spare batteries for cameras etc. (over 100Wh up to 160Wh) |
|---|---|
| 100Wh or less × 2 | Up to 2 |
| 100Wh or less × 1 + over 100Wh up to 160Wh × 1 | Up to 1 |
| Over 100Wh up to 160Wh × 2 | Not allowed |
Spare batteries of 100Wh or less (camera batteries etc.) have no quantity limit. Items over 100Wh up to 160Wh are limited to 2 in total, counting power banks and spare batteries (spare lithium metal batteries over 2g up to 8g for portable medical electronic devices also count toward this; lithium metal batteries over 2g for non-medical use are not allowed in carry-on or checked baggage). Power banks with sodium-ion batteries are not allowed in carry-on or checked baggage.
Source: MLIT: "Examples of Dangerous Goods by Air Transportation" (English version, last updated April 24, 2026) (retrieved 2026-09-27)
Some airlines have even stricter rules. Check your airline's guidance too.