– 43 –MAINTAINING YOUR SYSTEMTaking Careof Your SystemThe components of your security system are designed to be as free of maintenance aspossible. However, there are some things you can do to make sure that your system is inreliable working condition.1. Test your system weekly.2. Test the system after any alarm occurs (seeTESTING THE SYSTEM).ReplacingBatteries inWireless SensorsWireless sensors maynot have been used inyour security systemEach wireless sensor in your system has a 9-volt or a 3-volt battery. The system detects alow battery in any wireless sensor, including smoke detectors, the optional personalemergency transmitter, and the optional portable wireless keypad. A low battery in aportable wireless keypad is detected as soon as one of its keys is pressed, and the wiredkeypad will display 64.Alkaline batteries provide a minimum of 1 year of operation, and in most units andapplications, provide 2–4 years of service (4–7 years in units using 3-volt lithium batteries).Actual battery life will depend on the environment in which the sensor is used, the numberof signals that the transmitter in the sensor has had to send, and the specific type of sensor.Factors such as humidity, high or low temperatures or large swings in temperature, may alllead to the reduction of actual battery life in an installation.If you have a low battery in a wireless sensor, a low battery message is dis-played on the keypads.In addition, a battery-operated smoke detector with a low battery also emits a single "chirp"sound once approximately every 20-30 seconds, identifying itself as the smoke detectorwith the weak battery. If you do not replace a smoke detector's low battery, the smokedetector may sound continuously, as if there were a fire alarm.Note: The low battery message comes on as a warning that battery replacement inindicated sensor(s) is due within 30 days. In the meantime, the sensor(s) causing the lowbattery indication are still fully operational.Important: Use only batteries recommended by your installer as replacement.