The BRK SCO2B is an electrochemical battery-powered smoke and carbon monoxide alarm that is a great alarm for residential and institutional applications as hospitals, hotels, and dormitories. Alarm has a long lasting 9V battery with a loud 85dB horn.
In the box:
My unit is chirping once every minute or so. Change the battery still doing it. Going to try and silence it. Only 2 1/2 years old.
It seems that the alarm malfunctioned and since it is only 2.5 years, it should be covered by warranty.