SWISS power bank rules: 160Wh, no use on board

In checked bags

Not permitted as or in checked baggage

With approval

Over 100Wh up to 160Wh: airline transport approval required

How many

Max. 2 power banks per passenger

Using it on board

Do not charge devices from a power bank, or charge the power bank itself, during the flight (exception for approved medical devices)

Where to keep it

Do not stow in the overhead locker; keep under the seat, in the seat pocket, on your person, or in hand luggage

Packing

Prevent short circuits, e.g. by original packaging, taping exposed terminals, or a separate plastic bag/pouch per power bank

No. Do not charge devices from a power bank, or charge the power bank itself, during the flight (exception for approved medical devices).

In the airline's own words

• Power bank rules, airline by airline
• Power banks on Japanese flights