Data from FlightRadar24 shows the flight cruising at 36,000ft when almost three hours into its journey, over the Adriatic Sea, it took a sharp left-hand turn and landed 20 minutes later.
It is understood there was no issue with the power bank, but regulations state power banks are not allowed to be charging in the hold during a flight.
A spokesperson for the airline said: “The aircraft landed safely and passengers disembarked routinely and we provided hotel accommodation and meals where available. As some customers remained in the airport, they were provided with refreshments.
“The safety of its passengers and crew is EasyJet’s highest priority and EasyJet operates its fleet of aircraft in strict compliance with all manufacturers’ guidelines.
“We would like to apologise to all passengers for any inconvenience caused by the diversion and subsequent delay.”
EasyJet’s rules, external state that power banks are accepted on aircraft in cabin baggage only but are “prohibited from use” and “must not be used to charge other devices”.
A maximum of two power banks per customer are allowed, they must not exceed 160 Watt-hour (Wh) for lithium batteries and they must be individually protected such as in their original packing or a plastic bag.
Announcements are often made by cabin crew warning against their use.
Other airlines have brought in similar rules.
