Battery fire erupted after Ville Mäkinen put his child to bed

Fires involving lithium-ion batteries in homes are increasing, putting more pressure on rescue services and generating more insurance claims, Yle reports. In one recent incident, a battery exploded at Ville Mäkinen’s home in Valkeakoski.

Mäkinen had just put his child to bed when he heard a strange noise in the next room, where batteries for a lawn mower were charging. As he reached the doorway, one battery burst, sending burning pieces across the room.

He carried it towards the front door to limit the damage. By the time he reached the porch, a cell in the battery exploded and fell to the floor. Mäkinen escaped outside with his child and called the fire service.

“From the moment I heard the crackling, it took less than half a minute for flames to reach the ceiling on the porch,” he said. He feared the damage could have been much worse if the second explosion had happened in a bedroom.

Large batteries pose greater risks

Antti Määttänen, an insurance claims manager at Lähi-Tapiola in Pirkanmaa, said battery fires are appearing more often in claims. In many cases, the fire damages a surface such as a laminate floor or countertop rather than destroying a whole home.

Fire service statistics show about 150 fires across Finland started by a battery or cell in each of the past two years. Before 2019, there were fewer than 50 such fires a year.

Electric scooters, e-bikes and power tools are among the higher-risk devices because their large batteries can be hit or damaged during use. Fires involving batteries in larger tools can destroy entire buildings, Määttänen said. Fires involving smaller devices are often limited, but can spread if flammable materials are nearby.

Charge batteries with care

Kimmo Rytkönen, an instructor at the Emergency Services Academy Finland who helped prepare battery fire-safety recommendations, advises against charging batteries overnight or near flammable materials such as beds and pillows.

Large batteries should not be charged near an exit, he said. A rapid thermal runaway in an e-bike battery, for example, could quickly fill a hallway with toxic smoke and make it impossible to leave. Larger batteries can be charged on a balcony or in a washroom, where a fire is less likely to spread easily.

For small devices, Rytkönen recommends charging in a safe place, such as a kitchen counter near a sink, so the device can be put in water if necessary. Määttänen said he would not sleep in a home where a large battery was charging.

Damaged and unwanted batteries should be recycled, not put in mixed household waste, where they can cause a fire. The article also advises against keeping old devices as spares or charging batteries that have been out of active use, since their chemistry can become unsafe during storage.

Määttänen said he would like to see affordable fire-safe charging cabinets become available to consumers.