When and How to Change Your Smoke Alarm Batteries

Smoke alarms save lives – it’s a fact. According to Fire and Rescue NSW, 56% of fatal home fires between 2000 and 2014 occurred in homes where no smoke alarms were present. Having a working smoke alarm in your home is critical, so that’s why changing batteries and testing your alarms should be at the top of your priority list. 

Here are a few common questions we get asked about smoke alarm maintenance, and how you can make sure your smoke alarms are doing their job to keep your home and loved ones safe:

When Should I Replace My Smoke Alarm & Batteries?

According to Fire & Rescue NSW, the risk of a fatality in a home fire is halved if there is a working smoke alarm in a residential dwelling. Fully functional smoke alarms not only reduce the risk of fire – they save lives. This is why it is essential to keep on top of regularly replacing your smoke alarm batteries, regardless of whether you rent or own your house. It is recommended that you carry out this important task once every year. 

A good way to remember to change the batteries in your smoke alarms is to associate the task with a specific day that occurs each year. Many people choose to replace their batteries at the same time that they change their clocks back at the end of Daylight Saving each year. Others use April Fool’s Day (April 1st) as a mental trigger to change their smoke alarm batteries. Whichever date you choose, just make sure it’s an easy one that will remind you to keep on top of this life-saving job when it rolls around each year.

In addition to changing the batteries, you should also be replacing your entire smoke alarm every 10 years. The heat and smoke sensors become less sensitive as they age, which can result in a dangerous situation if an alarm doesn’t work when you need it to. Therefore, it is imperative that you make sure to remove and replace any smoke alarms in your home every 10 years, as required by law. Most models should indicate when they expire, so make sure to double check this when replacing the batteries.

How Do I Know When The Battery Needs Replacing?

Smoke alarms are clever little things – majority of models will let you know when the battery needs replacing. Most smoke alarms will emit small, high pitched chirping or beeping noises every 30-60 seconds to alert you to the fact that the batteries need to be changed. However, for the safety of yourself and everyone in your household, don’t wait until your smoke alarm tells you that the battery needs changing. Make a habit of replacing batteries annually, regardless of whether the alarm is telling you to do it or not!

And remember, mains powered smoke alarms also need their batteries replaced. Electric smoke detectors use a backup battery for situations where there is no power, and these backup batteries need replacing too. So it’s essential that you also change the battery in your mains powered smoke alarms, like you would a standard battery-powered alarm, so that they are still able to function in case of an emergency.

How Do I Test My Smoke Alarm?

It’s recommended that you make a habit of testing your smoke alarms once a month. This is a simple but effective process that gives you the peace of mind that your smoke alarms are functioning properly, protecting your home and keeping your loved ones safe. 

Testing your smoke alarms is as simple as pressing and holding down the ‘test’ button on your smoke detector – often using a broom handle can be helpful for reaching the button. If the alarm is working correctly, you should hear a loud, ear-piercing sound whilst pressing down on the button. If there is only a faint sound (or none at all) this is an indication that the batteries might need to be replaced. If replacing the batteries still doesn’t fix the problem, you may need to replace the smoke alarm itself. 

How Do I Change The Batteries In My Smoke Alarm?

The process of changing the batteries in your smoke alarm can vary between different models, but the basic steps remain the same:

  1. Climb up a ladder and locate the battery compartment of your smoke alarm. You may need to remove the alarm from the bracket holding it to the ceiling. 
  2. Climb back down your ladder and remove the smoke alarm cover – this can be done with your hands, though some models will require you to use a screwdriver. Check the instructions specific to your model, generally these can be found on the face or side of the alarm.
  3. Remove the existing battery and replace with a new 9-volt battery, paying attention to which way you insert the battery. It’s important to note that manufacturers do not recommend using rechargeable batteries, as they tend to lose their charge faster.
  4. With the new battery in place, put the cover back on your smoke alarm, climb back up your ladder and fix the alarm back into its bracket on the ceiling. Once this is done, make sure you press the ‘test’ button to ensure the smoke alarm is working properly. If there is no sound, try a different battery – otherwise you may need to replace the alarm.


It’s important to remember that it can take as little as three minutes for a fire to take hold and takes only two quick breaths of thick, black smoke to render someone unconscious (Fire and Rescue NSW), which is why making sure that your smoke alarms are working properly is absolutely critical. The risk of a fatality in a home fire is halved if there is a working smoke alarm.

If you require any advice on maintaining or updating your smoke alarms, where to install smoke alarms in your home, or need help testing your existing smoke alarms, Service Today is always  available to help. For more information, give our friendly team a call on 1300 859 383 or make an easy online booking today. One of our expert technicians will be able to assist you with any smoke alarm-related queries you may have, and can carry out a thorough check to ensure the alarms in your home are all working properly, keeping you and your household safe.