Lithium-ion batteries are found in almost every household in the United Kingdom, in common items such as mobile phones, e-cigarettes and cordless power tools. Larger types of lithium-ion batteries are found in e-scooters, bikes and electric vehicles.

These batteries are capable of catastrophic failure, entering a self-heating cycle or thermal runaway that generally results in a fire which spreads as the battery expels its material. These fires burn hotter, for longer and are more ferocious than other types of fire.

To understand the risk faced by UK households, home insurer NFU Mutual commissioned Yonder to conduct a poll of over 1,000 people.

It found that 80 per cent of people had done at least one thing to leave their device at higher risk of fire. Over half (57 per cent) had left a device charging overnight and 35 per cent when they were out, with 30 per cent charging devices on soft furnishings like sofas or bedspreads.

One quarte had bought a third-party charger online and 13 per cent had used a damaged or frayed charger, while six per cent had replaced a battery with a part not recommended by the manufacturer.

One fifth had left rechargeable batteries in devices like power tools and 13 per cent had left batteries in direct sunlight with eight per cent charging devices in direct sunlight.

Discussing the findings, Luke Barnett, Home Insurance Expert at NFU Mutual, said: “While it’s thankfully quite rare for batteries to fail, and are generally safe when used correctly, the results when they do unexpectedly start a fire can be devastating.

“As insurers, we see several factors that increase the risk of a battery fire and, shockingly, our survey suggests the vast majority of people are not charging or maintaining their devices in the safest way.

“It may seem over-cautious, but leaving a device on charge overnight or when you’re out, or using a third-party charger, can cause your device to overheat and catch fire. This risk only increases if you’re keeping the device on soft furnishings or in direct sunlight.

“Power tools and other products where the battery isn’t integral to the product are an often-overlooked fire risk. These items are infrequently used, allowing batteries to age and degrade, and may be stored in excessive heat or other unsuitable conditions, but can easily catch fire, with devastating consequences.

“While people may be tempted to save money by purchasing an unofficial third-party charger or replacement battery, this can greatly increase fire risk and ultimately lead to a much bigger bill – not to mention threatening your safety.

“With recent stories of devastating fires and tragic deaths in fires sparked by overheating batteries, we’re imploring everyone to take fire safety seriously when it comes to electrical devices."

NFU Mutual has received a number of property damage claims stemming from exploding e-bike, golf trolley and mobility scooter batteries to mobile phones overheating and starting a fire.

In one claim, a beard trimmer was left charging in a bedroom when it overheated, sparking a fierce blaze which caused fire damage in half of the property.

Beware of the hidden fire threat of lithium-ion batteries used in everything from phones, chargers and electric bikes