How To Reset A Smoke Alarm After Replacing Battery. Remove its battery then press the Test button and hold it down for 15 seconds. Because of this there is really only one reason for you to ever remove the battery and that is to replace.
You might still see the message low batt or bat but this is normal for up to 48 hours as the battery is likely charging. Remove its battery then press the Test button and hold it down for 15 seconds. And then press 72 through the keypad.
Replace the new battery in the detector and plug in the power supply.
Make sure there isnt a real actual fire. Other devices have similar low battery chirps or warning tones that sound like the chirp our alarms. Remove the battery from the smoke detector if there is a battery. Remove the detector from its mounting bracket and unplug the power supply.
