Battery Safety: 9 Volt | Expert Advice | Battery World
Battery Safety: 9 Volt
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15 April 2020


Smoke alarms save lives. There’s no doubt about it, and this is why it’s recommended that you replace the batteries once or twice a year.

If batteries are used, stored, and disposed of correctly, they pose little risk, but while they help save lives they can also be dangerous. When they’re not given the respect they deserve, problems can arise.

Most of us have a kitchen ‘junk’ drawer. It’s the place where spare light bulbs, business cards, receipts, birthday candles, batteries, paper clips, keys, and other paraphernalia are dumped. Don’t know what to do with something? Into the junk drawer; out of sight and out of mind.

Kitchen junk drawers have been linked to serious house fires. While there could be a number of causes, one of the major dangers is from 9V batteries. You can see a 9V battery in the image: it’s the one with its terminals side-by-side. If those terminals come into contact with material that creates a circuit, the electricity generates heat with can start a fire.

Steel wool is another common item in a junk drawer. Steel wool is made up of very thin iron wires. Touching the battery terminals to the wire sends a current through the wire, which heats up to about 700oC and causes the iron to react with oxygen to create iron oxide. This reaction releases more heat, which heats up the next bit of iron wire and so on. Pretty quickly a fire starts.

Imagine you needed something from the junk drawer. You’d open the drawer, get out what you needed, and push the drawer shut. What if something came into contact with the battery terminals and created a current? There are other flammable materials in the drawer and the drawer itself is timber. You’d happily go about whatever you were doing, perhaps even go to work or to bed, completely unaware of the trouble brewing in the junk drawer.

You’d be thankful you changed the smoke alarm battery, of course, but it’s a potential risk that can be avoided. Don’t store batteries in the junk drawer.

So once you remove the old battery, how do you dispose of it?

Tossing batteries in the general rubbish bin sends them to landfill, where they become a significant fire hazard. Instead, you could:

  • Place them back in the original packaging or into the packaging the new battery came from.
  • Put the plastic cap from the new battery over the terminals of the old battery.
  • Tape over the terminals with a piece of electrical tape.

When you next change your smoke alarm battery, keep this safety message in mind and dispose of your old batteries correctly and safely.

All Battery World stores have a recycling program for old batteries. You just need to drop off your old batteries and we recycle them safely and with a focus on the environment. Our mission is to Power your Future and Freedom; look after the planet whilst looking after your battery needs, and helping you live your lives with the freedom and safety you need.