Yesterday 17 December 2017 turned out different for the residents of a low-rise apartment block in Indianapolis. Because around 9 a.m. a women noticed smoke coming from a furnace-cum-storage room and evacuated the building. Fire investigators believe a lithium battery toy overheated and caused the fire. Everyone escaped unharmed. However, four apartments are currently uninhabitable owing to collateral damage from the incident.
What Made the Lithium Battery Toy Catch Fire?

It’s too easy to ask why the furnace room was a general storage area too. There may have been little control over what went in there, which is a heads-up for apartment managers.
We can imagine a parent using one as a hideaway for a much-anticipated Christmas gift. The temporarily homeless people include seven adults and three children.
What we do know is batteries are responsive to ambient temperature. The Journal of Electrochemistry published a paper we link to here as it’s highly relevant to the lithium battery toy incident. They tested the self-discharge rate of Sanyo C ∕ LiCoO2 full cells at ambient temperatures ranging from 0 to 60°C. There was ‘relatively little self-discharge for 0 and 25°C ambient temperatures, but significantly more for batteries stored at 60°C.’
What Caused the Battery Thermal Runaway?

Thermal runaway happens when batteries heat to the point the process becomes self-fulfilling. While the lithium battery toy was clearly faulty, the ambient temperature in the furnace room may have contributed to the problem.
But under normal conditions, this should not have happened. We shall have to wait for the fire investigators’ report.
We explored the idea of a household penny battery audit last July. Perhaps we should get into the habit of removing lithium batteries from toys when not in supervised use. We should probably do this anyway in the case of button batteries, because kids sometimes pop them in their mouths since they remind them of hard boiled sweets.
Related:
Lithium-Battery Safety Management Update
Christmas Gifts for Kids Battery Advice
Preview Image: Indianapolis War Memorial