Faulty lithium ion batteries are believed to be the cause of a fire on board a passenger plane.

A Lufthansa Airbus was flying from San Jose, California, in the USA to Frankfurt in Germany when a passenger’s portable power bank caught fire.

Cabin crew managed to extinguish the flames and cool the power bank down while the flight crew continued the flight to Frankfurt where the aircraft landed on schedule.

Power banks are batteries in a special case that stores electrical energy and so can be used to charge up small electronic devices such as mobile phones. The one pictured is a typical example of one.

This is the latest in dozens of fires on planes caused by lithium ion batteries which have ranged from exploding headphones which burned a passenger’s face through to fires in overhead lockers.

Passengers are advised to carry all electronic devices with them in the cabin because if they did become faulty and catch fire they can be doused.

If they were in suitcases in the hold and they caught fire next to a can of hairspray, nail polish or any other flammable item it could cause a severe blaze which could even bring a plane down.

* AvSax fire containment bags are now on board several major airlines worldwide and were deployed 27 times in 2017.

If an electronic device starts to seriously overheat or emit smoke the cabin crew will pour at least two litres of water into an AvSax. It is imperative to first knock down the flames from the device using an on board halon fire extinguisher, then transfer the device into AvSax before it reignites. Additional water is then required. The water activates the polymer gel inside the bag causing it to expand around the device. Should the device keep on venting then the AvSax is tough enough to absorb the energy.

The AvSax cools the batteries in the device, reducing the likelihood of the battery igniting but if it does go into thermal runaway it is all contained within the bag.

Amazingly, the water is absorbed into the internal lining of the bag so the device is dry when it is removed.