How to Replace the ADT Smoke Detector Battery

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ADT security systems are a great addition to any home because they keep your family and property more secure. The smoke detectors can also help you know when a fire or smoke is inside your home. Having working batteries in all your smoke detectors is essential for the safety of your home and family.

In this article, we will go over exactly how to replace the batteries in your ADT smoke detector easily and efficiently. We will also discuss how to know when the batteries are low and what kind of battery you should use for the replacement.

Put the System into Test Mode

Putting the system into test mode is always the first thing you should do before replacing the batteries in your ADT smoke detector or any other component of your ADT security system. If you don’t put the detector into test mode, it might go off or give you errors while replacing the battery.

Follow these steps to put the detector into test mode:

  1. Go to
  2. Select My Alarm on the dashboard screen.
  3. Select Menu.
  4. Choose System Management.
  5. Choose Place System on Test.

If you can’t access your account, you will need to call 800-ADT-ASAP. You will still need to provide account details, so make sure you know the username and password on the account.

Remove the Smoke Detector

Before changing the battery, you will need to twist the smoke detector in a counterclockwise direction. The mounting bracket will stay on the wall.  If the smoke detector is not twisting off easily, you might need to press the tab down with a screwdriver or sturdy pen.

Change the Battery

Once you have removed the smoke detector, put the new battery in. Make sure you are lining up the correct polar ends and using the same size and type of battery that was in the smoke detector originally.

Here are a couple of tips to remember when changing the battery:

  • Always ensure you have the correct polar sides lined up.
  • Recycle the old battery by turning it into a licensed recycler, so you don’t have to worry about correctly disposing of it.

Place the Smoke Detector Back onto the Bracket

Line the tabs and markings on the detector with the same ones on the mounting bracket. Turn the smoke detector in a clockwise direction to lock it into place. Make sure to wiggle it a few times to make sure it’s secure and won’t fall.

Reset the System

After replacing the battery of the smoke detector, you will need to reset the system so that it will sync and work properly again. Enter the code into your control system and hit Off twice. This should reset it.

Remove the System from Test Mode

You need to remember to remove the system from test mode. If you forget, it might not go off when it’s supposed to or be able to detect smoke.

Follow these steps to remove the smoke detector from test mode:

  1. Go to
  2. Click the My Alarm tab on the Dashboard screen.
  3. Choose System Management from the dropdown menu.
  4. Choose Step Test.

Note: If you’ve had a power outage, wait 48 hours to see if the low battery alert goes away on its own.

How Do I Know the Batteries in My ADT Smoke Alarm Are Dead?

It’s always a good idea to know when your smoke detector batteries are about to die. Knowing when to replace them before they die will ensure your home is protected. The alarm keypad and ADT pulse app should both alert you the battery is about to die.

  • The alarm keypad will show a zone trouble indicator. It should flash and beep to get your attention.
  • The ADT Pulse App will show a sensor trouble indicator. The app will send you a notification if you have them enabled, and the alert will show on your app’s dashboard screen.

Once the indicators show, you need to replace the battery as soon as possible. Having spare batteries on hand is always a good idea so that you can replace them as soon as you see the indicators on the keypad and app.

What Kind of Batteries Does the ADT Smoke Detectors Use?

Most ADT smoke detectors use two CR123A batteries. However, some smoke detectors only use one battery. The batteries can be bought easily at several different places, including:

  • Amazon
  • Local hardware stores
  • Mass retailers
  • Special battery or tech stores
  • Walmart
  • Target
  • CVS and other pharmacies


Check for notifications on your keypad and app to make sure the batteries in your smoke detector are not about to die. When it is time to swap out the batteries, always use the correct replacement batteries.

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