How to Replace the ADT Motion Sensor Battery

motion sensor mounted to a corner of a wallmotion sensor mounted to a corner of a wall

When you buy through our links, we may earn an affiliate commission.

The ADT motion sensor provides a reliable way to keep you informed about movement on and around your property. While the batteries are long-lasting, eventually, you will receive an alert on your system letting you know that it is time to replace them. Taking care of this as soon as you receive the notification helps your system return to full operation quickly.

When you are ready to replace the battery after receiving notification that it is required, there are steps to follow that will have the replacement finished quickly; keep reading to learn more.

How to Replace the ADT Motion Sensor Battery

Replacing the ADT motion sensor battery requires a CR123A 3-volt battery. Depending on your model, you may need one or two batteries. After putting your system into test mode, unscrew the motion sensor’s cover, replace the battery, and exiting test mode will complete the process.

The reliability of the motion sensor is dependent on the power provided by the internal battery. The CR123A 3-volt battery is a long-lasting and easy-to-replace requirement for the motion sensor.

  1. Before replacing the battery, visit the ADT website, log into your account, and place your system into test mode. This will prevent any false alarms from occurring.
  2. Depending on your model, the panel you will need to unscrew could be located on the top or bottom. Using a screwdriver, remove the screw. Then, use a flathead screwdriver to press the tab on the bottom, opening the battery location.
  3. After removing the current battery, insert the new battery into the location, ensuring proper polarity.
  4. Replace the panel, and then secure the screw back in place.
  5. Return to the ADT website and remove your system from test mode. This will complete the process and restore the full operation of your system.

Watch this helpful video to view the process of replacing the motion sensor battery.

Troubleshooting Tips When Replacing the ADT Motion Sensor Battery

The steps for replacing the ADT motion sensor battery make it easy for you to tackle this issue. However, there might be an occasion when replacing the battery does not seem to resolve the issue. To check this concern, you may need to investigate if the sensor is faulty and not a low battery issue.

Occasionally, your ADT motion sensor could become disconnected from the ADT app and appear not to be working or even not showing up at all. When this occurs, replacing the battery will not solve the issue in most cases. While a low battery can certainly also be an issue, troubleshooting a sensor can help solve this issue to help you determine if it is a battery concern or related to connection issues:

  • If the motion sensor is more than 350 feet from the main hub, you may not be able to detect the sensor. Not finding the motion sensor listed in your app’s device list might indicate a disconnected sensor rather than a battery issue.
  • After making sure that the ADT system is disarmed, you can investigate the motion sensor connection. Putting the system into test mode can also increase the safety of this procedure in avoiding false alarms.
  • When you see the motion sensor connected and working in the app, and the battery is still showing as needing to be replaced, there is the possibility that the new battery might be damaged, not working, or the polarity could have been reversed. Repeat the battery replacement steps and start with a fresh battery, ensuring proper polarity.

If these steps do not resolve the motion sensor battery issue, you may need to contact a professional at ADT to help investigate this issue further. ADT’s experienced professionals can help you further troubleshoot this issue and find out why the battery replacement has not worked to restore the sensor’s functionality:

  • Visit the main ADT help page here, where you can navigate to other areas of support.
  • Typing the issue into the search box can guide you to articles that can help you solve the issue.
  • Contacting ADT is the next step if you cannot find an adequate solution after researching the issue. At the bottom of the main help page, you can find multiple ways to connect with ADT, including social media sites and a convenient 24-hour helpline to call.


The ADT motion sensor offers multiple ways to detect motion in and around your home. When the battery is low, replacing it with a fresh battery is easy, so you can get your system back to full operation to monitor your property.

Keep Reading