A new type of high tech luggage which has inbuilt lithium-ion batteries are being banned by some airlines.

Major companies such as American Airlines and Delta Air Lines fear batteries pose a fire risk and so will no longer allow the new ‘smart luggage’ on board unless the batteries can be removed.

Smart luggage is a small but growing corner of the more than $6 billion global luggage market. These suitcases feature USB ports that allow passengers to charge their electronic devices, such as mobile phones.

One of the main suppliers, Away, says travellers can charge an iPhone five times before they must plug in the charger. Batteries in some Smart luggage can be removed.

Delta said it made its decision "due to the potential for the powerful batteries to overheat and pose a fire hazard risk during flight."

A spokeswoman for Southwest Airlines said the carrier was "in the process of reviewing our policies and considering changes."

American Airlines said smart luggage "contain lithium battery power banks which pose a risk when they are placed in the cargo hold of an aircraft.

"As part of safety management and risk mitigation we always evaluate ways to enhance our procedures, and the safety team at American has conducted its own analysis of these bags.”

Lithium-ion batteries are a top concern for the aviation industry. A Trump administration ban earlier this year required passengers from certain Middle Eastern airports to check their electronic devices larger than a mobile phone. That laptop ban, which has since been scrapped, drew concern about battery fires in the cargo hold.

Fires may be tougher to put out if they are in the harder-to-reach luggage hold than in the cabin where crew members have easy access to extinguishers or fire containment bags.

* AvSax fire containment bags are now on board several major airlines worldwide. 

They have been deployed on aircraft 20 times so far this year and means they don’t need to make an emergency landing and can continue the flight confident the bag has solved the problem. The average cost of an emergency diversion in the USA is $400,000. 

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 and then drop the burning device into the bag, adding additional water as 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 force. 

The AvSax cools the batteries in the device, reducing the likelihood of the battery catching fire but if it does go into what is known as thermal runaway when all the battery cells catch fire at incredibly hot temperatures 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.