With temperatures across Wales finally soaring this week, homeowners are being warned not to leave mobile phones or laptops charging in direct sunlight to minimise the risk of battery-related fires.

Many insurers have witnessed a sharp increase in claims over the past year for home fires caused by lithium-ion batteries, according to Freddie Hamilton-Russell at home insurance broker Lycetts.

These are commonly found in rechargeable devices in and around the home from mobile phones, tablets, laptops and electric toothbrushes to vapes, power tools, smart home devices like doorbells and electric bikes.

While normally safe to use, such batteries can present a significant fire risk if the battery is exposed to extreme temperatures, over-charged, short-circuited, damaged or submerged in water.

“Fires caused by lithium-ion batteries can also prove more difficult to extinguish, starting with a heat reaction before what’s known as thermal runaway, smoke, fire and often an explosion,” explained Hamilton-Russell, “so it’s vital that homeowners take a few simple precautions to minimise the risk of battery-related fires.”

Hamilton-Russell warned against leaving any equipment that may contain lithium-ion batteries, including mobile phones, in high temperature environments above 45⁰C, such as in direct sunlight in your home, or in a hot vehicle, where temperatures can reach 70⁰C when parked in the sun on a hot summer’s day.

“When charging, it’s essential to only use manufacturer-approved chargers with safety features designed specifically for the device,” he said.

“Avoid overcharging the battery by disconnecting your device when fully charged and unplugging the charger.  Don’t leave batteries charging continuously unattended, especially overnight or if you are out of the house, and try to avoid charging them on soft surfaces such as beds or other flammable materials where heat can’t dissipate.

“Never charge batteries or devices in hallways or doors where a fire could potentially block your escape route. And don’t cover chargers or battery packs when charging, as this can also accelerate overheating.

“Always use the original battery and power cord recommended by the device manufacturer or a compatible replacement which meets UK safety regulations from a trusted supplier.

“Never charge batteries or devices in high temperatures or direct sunlight, as this can lead to overheating and pose a fire risk.

“Keep an eye on your battery and device for any signs of damage such as overheating, bulging, dents, unusual smells, hissing, leaking or poor device performance, and stop using it immediately if this happens.

“When not in use, keep devices in a cool, dry place away from direct sunlight and flammable materials. And finally, check your smoke alarms are all still working.”

For guidance on insurance cover, homeowners are advised to seek expert advice from a specialist broker.