The One Bag You Can’t Check In To Airlines Like Ryanair

Between the newly-enforced EES rules and jet fuel price-induced cancellations and suspensions, 2026 is proving quite the year for fliers.

If you don’t want what may be an already more-tiring-than-usual process to take even longer, Ryanair has said on its site that not all bags can be checked in.

“Smart bags”, or bags with a lithium battery and charging port, cannot be checked in to the hold if the battery can’t be removed.

Even if you can remove the battery to check the bag in, their site reads, “The battery must not be placed in the hold under any circumstances.

“The removed battery must be carried with you in the cabin and placed in small baggage that is placed underneath the seat in front of you or on your person.”

Removed batteries must not be placed in the overhead lockers. The removed battery can’t be more than 100Wh, either.

If the battery is not removable, Ryanair said it must not exceed 2.7Wh.

The ‘Wh’ stands for watt-hour and is generally on the battery. If it’s not, the UK Civil Aviation Authority said: “If only the milliampere hours (mAh) are marked on the battery, then divide that number by 1000 to get ampere-hours (Ah). For example, 4400 mAh / 1000 = 4.4 Ah.”

“Smart bags with non-removable batteries above 2.7Wh are not permitted onboard,” says Ryanair.

The UK Civil Aviation Authority said on their site that, “Baggage equipped with a lithium battery(ies) exceeding 0.3 g for lithium metal batteries, and a Watt-hour rating of 2.7 Wh for lithium-ion batteries, must be carried as carry-on baggage unless the battery(ies) is removed from the baggage, protected from short circuit and carried in the cabin.”

In other words, smart bags with lithium batteries generally can’t go in the hold on most airlines.

It’s due to their lithium batteries.

These can catch fire if they’re damaged or if they short-circuit.

That’s why they’re generally only permitted in hand luggage, where people can keep a closer eye on them.