How To Replace ADT Alarm System Battery

Is there a display message on your ADT Pulse home alarm system that reads, “LowBat” or “low battery”? When a battery inside your ADT security system is getting weak and needs replacing, your system may send you an alert or show “low battery” on the keypad display.

To replace the battery, you’ll need to order a new one, but this is where it can get a little tricky because different ADT security panels require different size batteries. In most cases, the alarm panel requires (1) 12 volt, 4, 5, 7, or 8 Amp Hours Sealed Acid battery. It’s a safe bet to purchase the same size battery as the one you are about to replace in your ADT system. To ensure you are ordering the correct replacement battery, use ADT as a resource.

adt low battery message

How to order a replacement battery for your ADT system

To ensure you purchase the correct battery for your ADT system, you can order directly through ADT or use their self-service battery help guide which will help you find a local supplier with batteries that meet your alarm system requirements.

How to install your ADT alarm system replacement battery

It’s important to first place your alarm system into test mode to prevent false alarms before you move forward replacing the battery. Follow the steps below to put your system in test mode and how to replace the battery in your security system:

1. Log into your account and select "My Alarm" from your dashboard.

  • Once you select "My Alarm", a new menu will appear.

2. From this menu, select "System Management".

3. Choose the option "place system on test".

4. Now you are ready to open the panel to the ADT system. In some cases, you might need a key to open but it is located at the top left of the panel in most cases. If not there, you will need to push down on the tabs on the keypad panel and you will find a green battery that has a little pin connector.

5. Disconnect the wires on your battery by gently tugging them.

6. Replace the battery by connecting the red wire to the red tab on the battery and the black wire to the black tab.

7. Once the battery is connected, close the door to the security panel.

Note: There is a chance you will still see a low battery display on the screen of your system for up to 48 hours while the battery charges. The “low battery” display should clear on its own once the new battery is recharged.

Now you want to remember to remove your ADT alarm system from "test mode".

8. Go back to and click on "My Alarm".

9. From the System Management option, select "Stop Test" to remove the system from the test mode and restore operations.