If your smoke detectors are battery-operated, the chirping sound generally signals that it’s time to change the battery. If that doesn’t stop the chirping, we have found that the best solution is to replace the detector.
Smoke detectors, like light switches, are not manufactured in a way that they can be opened and repaired. Whether your smoke detector is battery operated or hard-wired, you should be able to look at the label on the detector to determine when the device was manufactured as well as when the manufacturer recommends replacing the detector.