How To Replace the Smoke and Carbon Monoxide Alarm Listener's Battery
The Smoke and Carbon Monoxide Alarm Listener takes one CR-123A Lithium 3 volt battery, and has a life expectancy of up to 3 years, depending on usage.
To replace the Alarm Listener’s battery, twist it counter clockwise off its bracket to reveal its battery. Put in a new CR123A lithium 3 volt battery and twist the device back on its bracket.