Mobile phones are causing an increasing number of house fires due to incorrect charging methods, a major Australian insurer has claimed. 

Allianz Australia said a new analysis of claims data showed phones were now behind more lithium battery fires than their larger counterparts like e-bikes and e-scooters. 

Lithium batteries are causing hundreds of fires across the country each year, with Allianz revealing it received $16.1million in claims for incidents involving the devices in the last year alone.

While the dangers of these larger devices are increasingly known, the insurer said many people were unaware that smaller devices like phones also present a risk and were complacent about charging them safely. 

‘It’s a myth that if you don’t own an e-scooter you don’t have to worry,’ Chris Wood, Allianz emerging risk manager, told The Daily Telegraph.

‘The common theme is that people are charging them in bed. You’re not supposed to charge them on top of flammable items, but people will charge them under doonas and pillows,’ he said.

‘Mobiles will heat as they are charged and will heat further if they are getting updates. Imagine that in a bed with added body heat and the electric blanket on.’

According to Allianz data, lithium battery powered garden tools and power tools were behind the most fires at 38 per cent of claims.

Lithium-ion battery-related fires are occurring at a rate of one every four days in NSW (pictured a house in Sydney’s eastern suburbs following a lithium battery fire)

This was followed by devices with battery cells like flashlights at 31 per cent.

Mobile phones were at 12 per cent and then were e-bikes and e-scooters were below that at 11 per cent.

Mr Wood said overcharging phones, such as leaving them plugged in overnight, also presents a risk and they should be unplugged as soon as they reach full charge.

Allianz investigators found people were also swapping cords or chargers between devices, which can increase the fire risk, and charging them on the ground where clothes can be thrown on top.

UNSW expert, Dr Matthew Priestley from the School of Electrical Engineering and Telecommunications said heat is what causes lithium battery fires.

‘I don’t think there is enough education regarding proper use, and storage, and recycling or disposal of lithium batteries and that is the key moving forward.’ 

He said the batteries typically contain a liquid electrolyte solution that has lithium salts dissolved into a solvent, such as ethylene carbonate.

This mixture produces a lot of electricity but is highly volatile and flammable, which creates a serious risk of fire or explosion, particularly when exposed to high temperature.

Phones made up 11 per cent of lithium battery fire claims to insurer Allianz last year (stock)

‘In addition to this, the way a lithium-ion battery produces power also generates heat as a by-product.

‘The major issue with lithium batteries overheating is a phenomenon known as thermal runaway.

‘In this process, the excessive heat promotes the chemical reaction that makes the battery work, thus creating even more heat and more chemical reactions in a disastrous spiral.

‘When they do catch fire, this makes them extremely hard to put out.’

According to Dr Priestly, phones should be charged uncovered on a non-flammable surface using genuine cords and chargers for that device.

They should also be kept out of direct sunlight and away from heaters.