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How to Change Smoke Alarm Battery – Stop your Detector from Chirping!

Smoke detectors reduce your chances of dying in a fire by 50%. This number makes it one of the must-have tools at any place, whether home or office. No matter the area, a smoke detector makes every place safer. Of course, like most appliances, a smoke detector works on a battery that needs to be changed from time to time. Most detectors will tell you when to change the batteries through a chirping noise. Here’s how to change battery in smoke detector before it disturbs you.

Fire Alarm Safety Tips

Safety comes first. Here are three safety tips that you must follow:

  • Placing smoke detectors in the right places is crucial in ensuring safety. Therefore, it is recommended to have one on every house level, hallway, and bedroom.
  • Replace batteries twice every year.
  • Replace your smoke detectors every ten years. Smoke detectors can only live up to a decade.

How Often to Change Smoke Detector Batteries?

Before knowing that lets see how long do smoke detector batteries last! The fire alarms have either 9V alkaline batteries or AA batteries or Sealed Lithium batteries. Now, coming to the battery life, 9V or AA batteries lasts for 6 to 12 or 18 months while Lithium batteries lasts longer for 8 to 10 years.

Changing a smoke detector battery is an overlooked task that is vital to a very great degree. Timely changing the batteries cannot be emphasized enough. There have been several fatal fires where the smoke detectors did not have batteries or the house’s detectors were not working. These alarming incidents demonstrate the significance of checking your smoke detectors from time to time. 

This brings us to the question of when you should change the batteries. This depends on many factors, such as the quality of the battery, power consumption, or even the environment. Usually, the batteries last for about six months or a year but certainly not up to two years. 

There are sure signs that would indicate that it is time to change them. For example, a common indication that the batteries need to be replaced is that the smoke detector would make a chirping or beeping sound. It is recommended to replace the batteries before this occurs. Nonetheless, ensure that you are proactive in such a situation and change them immediately. 

A great way to remember to replace the battery of your smoke detector is to change them when you are changing your clock’s batteries. Another reminder could be half-yearly changing or writing it down to ensure you don’t forget it.

Smoke Detector Still Beeping with New Battery?

If your smoke detector is chirping/beeping, showing that the batteries require change, it is a good sign as it indicates that the detector is still working. However, it is also possible that the device continues to chirp/beep despite the battery replacement. In this case, wait for some time or check whether the battery has been inserted the right way.

Smoke Detector Beeping without Battery?

Generally, smoke alarms comes with a battery backup and this help the device to chirp or beep when there is any dust or due to any circuit/device/battery backup problems. Nevertheless, to stop the beeping your device needs a reset after ejecting the battery from it.

How Often to Replace Smoke Detectors?

According to National Fire Protection Association (NFPA), it is best to replace smoke alarms for every 10 years. You might ask how long do smoke detectors actually last? Usually, the life span of any smoke alarm varies from 8 to 10 years. If the detector is used more than a decade, it gets old and the dust makes it hard to detect the smoke.

As mentioned above, you will be required to change the batteries for every 6 months. But if you bought the 10-year sealed battery alarms, you can eliminate these replacements and beep sounds for up to 10 years. However, smoke detector battery replacement is not a big task if you follow the below-mentioned steps.

How to Change Battery in Smoke Detector?

Typically, smoke detectors come with a covering that can either be lifted off or be hinged down. However, there are some other types where this cover is attached to the base, usually on a ceiling. You can unhook the covering in such alarms by twisting clockwise. Also, if you have a hard-wired smoke detector, turn off the power circuit to avoid an electric shock while replacing the batteries. 

Regardless, before replacing the alarm’s batteries, be sure to change the detector’s settings to a test mode. To do this, go to the mobile application or visit the customer portal, although you can even call the company’s monitoring center to do the same.

 [3 Step Guide] How to Replace Smoke Detector Battery?

With that being said, let’s see a step by step process to replace the battery in a smoke alarm:

Step 1: Take off the cover

You will need to detach the alarm’s cover in the first step. Generally, most detectors can be removed by twisting them anticlockwise. There are models, too, whose covering can be unclipped by a screwdriver or be popped open by fingers. Nonetheless, read the user manual to get better guidance to undo the covering safely. 

When you have successfully opened the smoke alarm, you will see three main components: An alarm horn, the sensor chamber, and the battery.

Step 2: Change the batteries

Next, pull out the old batteries and replace them with new ones. Some also recommend taking out the batteries and waiting for about 20 seconds to power down.

Usually, if you have a smoke and carbon monoxide alarm, it’s best to use 9-volt lithium batteries as they last longer (around ten years). Apart from this, if you have a smoke and heat detector, you’ll require 3 AAA batteries. Altogether, be sure to correctly position and connect the battery, that is, place the positive and negative sides according to the labels.

Step 3: Put the cover back on

Once you’ve replaced the batteries, close or lock the lid depending on your smoke detector type, you might have to snap the outer cover back into its place or tighten it with a screwdriver and lock it.

As a note, radon detectors are also as important as the smoke alarms. So, if you haven’t bought one, check out our list of best radon test kits available in the market.

How to Check after Smoke Alarm Battery Replacement?

Now that the batteries have been replaced, it’s essential to check if they’re working. One way to quickly test the detector is by pushing the test button on the detector. The detector should make a beep or chirp noise if the battery is working to inform you.

In addition, detectors also have a LED light that blinks every 12 seconds, which is another way to ensure the alarm is working.

What Kind of Batteries do Smoke Detectors Take?

For many years, battery size for smoke detector is of 9V. But now, most of the fire alarms are replaced with AA batteries. These AA batteries have 3 times more energy as a 9V battery. So, it is no surprise to see two or three AA batteries instead of one 9V battery in the smoke detectors now-a-days.

Also, we need to talk about Lithium batteries which are currently becoming popular. They last for the entire lifespan of the detector and some can also be recharged. New alarms are coming with sealed lithium batteries which we can’t (and of course not necessary) to change or replace for the whole lifetime of the device.


In a nutshell, it’s a pretty straightforward process to replace the batteries of a smoke alarm. Of course, it’s always much better to change the batteries before the appliance noises all over your home or office. However, one crucial thing to remember; to safely take out the covering and reinstall the new batteries without getting a shock. Overall, remember to put a working battery; you can even test it beforehand. If you do that, you’ve become a battery-changing expert!