Power banks on flights go by watt-hours: 20,000 mAh is about 74 Wh, with a Dutch limit of two per person and no use on board

On the evening of 27 September a Lufthansa flight from Frankfurt to Lisbon diverted to Lyon after a power bank caught fire next to a seat; NOS reports that a week earlier a power bank also ignited on a KLM flight to Curacao. If you are booking a trip home or a break before the autumn holidays, the first thing to understand is that security and airlines do not look at milliamp-hours but at watt-hours (Wh). ILT, the Dutch inspectorate for aviation safety, states that anything up to 100 Wh needs no permission, 100 to 160 Wh needs the airline's approval and anything over 160 Wh never goes on board; each person may carry at most two power banks, in hand baggage only, and on board you may not charge the power bank or use it to charge your phone. Next step: turn your power banks over tonight and look for the Wh figure.

• Work out the watt-hours yourself: Wh = mAh x volts / 1000. Most power bank cells run at 3.7 V, so 10,000 mAh is about 37 Wh and 20,000 mAh about 74 Wh, both under 100 Wh; you reach the 100 Wh line at roughly 27,000 mAh. If the Wh figure is printed on the back, that printed number is the one that counts.
• KLM is stricter than many people expect: at most two power banks per person; if the capacity in Wh is not listed on the power bank you may not be able to bring it; keep it with you rather than in the overhead bin; no using or charging it on board. Transavia's own page allows up to 20 spare lithium batteries of up to 100 Wh each, but ILT caps power banks at two per person, so packing for the stricter rule is the safe choice.
• One extra rule if you fly on to China: since 28 June 2025 the Civil Aviation Administration of China bans power banks without a CCC mark, with an unclear mark or from recalled batches on domestic flights. If you connect from Amsterdam onto a domestic Chinese flight, check the casing for a clear CCC mark; European models bought in the Netherlands often do not carry one.
• Check before you leave: two or fewer, in your carry-on, Wh printed on it, no swelling and no recall. ILT says damaged, defective or recalled batteries may not travel at all, so rather than losing an old one at the airport, hand it in as battery recycling in the Netherlands first.

Hokimi field note: keep a photo of the back of each power bank on your phone so you can check the watt-hours while booking; finding out at the security lane means leaving it behind. Sources: source 1, source 2, source 3, source 4, source 5, checked on 2026-09-28.