Customer FAQs Discover answers to the most frequently asked questions from ADT customers with the click of a button. 1. How can I replace my alarm system battery? When a battery is getting too weak and needs replacing, your system may send you an alert or show ‘Lo Bat’ on the keypad display. The Alarm Panel requires (1) 12 volt, 4, 5, 7 or 8 Amp Hours Sealed Lead Acid battery. The size of the battery depends upon your specific panel and the types of equipment you have installed on your system. Make sure you purchase the same size battery as the one you are about to replace. 1. Before you replace the battery, put your system into test mode to prevent false alarms. 2. Log into MyADT.com and select “My Alarm” from the dashboard. 3. Once you click “My Alarm”, a menu will appear. From the menu, select “System Management”. 4. Select “place system on test.” (Note: You can also call 800-ADT-ASAP to put your system into test mode.) 5. Open your system’s panel. (If you need a key to open your panel; the key is often left on top of the panel.) After opening the panel, disconnect the wires on your battery by gently tugging on 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 panel. Note: The low battery indicator may be displayed for up to 48 hours while the battery charges. The indicator should clear the message on its own once the batteries are recharged. 8. Remember to remove the system from “test mode.” 9. Go to MyADT.com and click on “My Alarm." 10. From the System Management option, select “Stop Test“ to remove the system from test mode and restore operations. If you’re unsure of what kind of system you have, watch this video.