How to Change the Battery in a Smoke Alarm

To keep your home and family safe, having smoke alarms is paramount. Not only could they, most importantly, save your life, but they could also save you huge sums of money on repairing any damage to your home if a fire broke out. They’ll also help with your insurance, as well as your peace of mind.

But of course, the batteries will at some point need replacing. In this guide we’ll detail how to change the battery in a smoke alarm and which type of smoke detector batteries can actually be replaced.

Smoke alarms can have different types of batteries which last for varying periods of time, and some can’t be replaced.

Lithium batteries which last for ten years can’t be changed – you’ll need to replace the entire alarm. 

Many detectors use a 9V battery, while some use another type. These can be replaced, whether they’re hardwired or not.

Make sure you always use good quality, long-lasting batteries. Rechargeable batteries won’t cut it as they could cause your alarms to fail.

To change the battery in your smoke detector, simply follow these steps: 

Remove the smoke detector

Most alarms can be removed by twisting or sliding them off their mount on the ceiling. With others you may just have to remove the casing to uncover the battery compartment. 

Replace the battery

Each smoke alarm will be slightly different when it comes to where the battery is located, but if you remove the cover then you’ll usually be able to see clearly where it is. 

- Remove the cover, using a screwdriver if there’s a small screw keeping the battery compartment cover on.

- Check your user manual if you’re not sure where the battery is. If you can’t find your manual it’s worth checking the manufacturer’s website.

- Replace the batteries, making sure the positive and negative ends match. 

- Replace the battery cover or smoke detector casing. 

Test the battery

This is an important step so don’t skip it! 

- Press the test button, which is usually clearly located on the front of the alarm, to check it sounds. 

If it doesn’t work…

There might be a simple solution to the problem if your alarm doesn’t sound when you test it.

- Check the batteries are installed the right way, with the positive and negative ends matching the correct terminals. 

- If your alarm still doesn’t sound when you test it again, try swapping the batteries for some new ones. 

- If it still doesn’t work, your alarm might be faulty so either buy a new one or contact the manufacturer if the warranty hasn’t expired. 

Did you know you’re meant to test your alarm once a week? This will help you and your family stay safe. 

Remember, it’s good to have all bases covered when it comes to fire safety. Browse our range to find a small extinguisher or two to keep in your home, and/or a fire blanket in the kitchen, where a fire is most likely to break out. 

Don’t forget your carbon monoxide detectors – read more about the importance of these alarms in our guide on how to spot and prevent CO poisoning, and enjoy the peace of mind of keeping your home and family safe.