A common household item is causing fire departments some concern.   

A 9-volt battery can be a fire waiting to happen. Jeff Holmyard of the Barrie Fire and Emergency Service says it's because of the unique design of the battery.

He says it’s “because the terminals are so close together.”

“With other batteries the terminals are end to end,” he says.

With a simple experiment – placing a coin on top of a 9-volt battery – “now I've made a connection. I've got a circuit and electricity is flowing,” says Holmyard.

Using a heat-measuring thermal imaging camera, after only a minute and half the temperature in the battery was measured at 140F.

“The thermal imaging camera is telling me the temperature in that battery is now 60C – that's half way to the boiling point.”

The temperature eventually climbed to 65.5C – so storing a 9-volt battery in a combustible area like a kitchen drawer could easily lead to a fire.

Some battery manufacturers provide safety storage caps for batteries. If one is not provided, fire officials say covering the ends with electrical tape or a plastic bag is acceptable.

“If you’re storing one of these, make sure there's nothing conductive that will unite these two termini,” Holmyard says.

If you have any questions about safe battery storage or the storage of any other combustibles, the Barrie fire department has the answers.