Valkeakoski porch destroyed in battery blast as experts urge against overnight charging

A Valkeakoski man's porch was destroyed last summer when lawnmower batteries exploded, and he and his child escaped unharmed, according to YLE. Pelastusopisto is now warning residents not to charge batteries overnight as battery-related fires increase across Finland.

Such fires are tying up rescue services and appearing more often in insurance claims. The trend follows Lähitapiola Pirkanmaa's earlier warning about a rise in power-tool battery fires.

Pelastusopisto teacher Kimmo Rytkönen and Lähi-Tapiola Pirkanmaa claims manager Antti Määttänen said incidents have risen to about 150 nationwide in each of the past two years, up from fewer than 50 annually before 2019.

Ville Mäkinen said he heard a pop and saw burning fragments. He carried a battery toward the door, but a second cell detonated and flames reached the porch ceiling in under half a minute.

Experts advise against recharging long-unused cells, and say never charge batteries overnight or on a bed. Place small devices on a kitchen counter by the sink so they can be submerged if needed, and keep large batteries away from exits. Impact damage, water exposure and cheap imported units can increase the risk.

Määttänen said insurers generally cover fires caused during normal use but may reduce or deny compensation if a battery was clearly misused.