Smoke Alarm Battery Chemistry Alkaline Battery Location Back Battery Locking Pin Yes Battery Size 9V Communication Protocol Not Applicable Compatible With Not Applicable Detector Type Smoke Detector Features Hush Button Includes 9V Battery Number of Tandem Detectors Not Applicable Power Source Removable Battery Sensor Type Ionization Photoelectric Visual Alert Type Red LED Volume Level 85 dB @ 10 ft Alarm Setting 30 ppm Battery Backup No Humidity Operating Range 85 Percent RH