AN URGENT warning has been issued to travellers over a little-known baggage rule - and ignoring it could be deadly.
Brits trying to fly abroad with a power bank to charge their phones must beware of the rules around what planes will allow onboard.
Battery packs taken onboard cannot exceed a 100 Watt-hour limit.
If travellers try to take the packs on board they are more likely to cause a life-threatening fire.
Lithium batteries can produce dangerous heat levels, cause ignition, short circuit very easily, and cause inextinguishable fires.
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Joe, from Grepow rechargeable battery, said: "They may seem small, but the impact they can have when they cause a fire on board is unimaginable."
He added that viral videos have been posted to YouTube "showing these gadgets bursting into flames".
It comes after influencer Pandora Sykes revealed she was banned from a flight for trying to check-in suitcases with USB ports.
She said: "Beware anyone being so foolish to fly easyJet.
"The captain just refused to let us board our flights because our checked-in suitcases have USB ports aka smart bags.
"And no refund, obviously. I hate them with the fire of a thousand suns.
"We didn’t realise they had changed their conditions. We’ve flown lots with these bags before."
Smart bags come with features including charging points, Bluetooth connections, WiFi hotspots and electronic locks.
Many airlines ban them because of their inflammable lithium batteries.
In January this year two passengers suffered burns after a power bank portable charger burst into flames on a flight from Taiwan to Singapore.
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A clip of the blaze shows passengers screaming as smoke and flames billow from a row of seats.
In February a United Airlines flight was forced to turn around mid-flight and return to California after a passenger's battery pack caught fire in the cabin.
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