Remove the detector from the SmartBracket by turning it counterclockwise.
Turn off the detector by holding the power button for 3 seconds.
Place the front side of the detector — the one with the Ajax logo — on a soft cloth so as not to scratch the enclosure.
Loosen four screws with a PH0 cross-head screwdriver.
Remove the back part of the detector.
Replace two CR123A batteries following the polarity indicated on the detector.
Never install used or damaged batteries.
Reinstall the back part of the detector enclosure.
Tighten four screws with a PH0 cross-head screwdriver.
Turn on the detector and check the battery status in the Ajax app