Smoke Alarm Battery Chemistry Carbon Zinc Battery Location Back Battery Locking Pin Yes Battery Size 9V Communication Protocol Not Applicable Compatible With Not Applicable Detector Type Smoke Detector Features Test Button Intermittent Red LED Includes 9V Battery Number of Tandem Detectors Not Applicable Power Source Removable Battery Sensor Type Ionization Visual Alert Type Red LED Volume Level 85 dB @ 10 ft Alert Type Sound Battery Backup No Detects Smoke