– 32 –MAINTAINING YOUR SYSTEMTaking Care of YourSystem The components of your security system are designed to be as maintenance-free as possible.However, to make sure that your system is in reliable working condition:1. Test your system weekly.2. Test your system after any alarm occurs (see TESTING THE SYSTEM).ReplacingBatteries inWireless SensorsWireless sensorsmay not have beenused in yoursecurity systemEach wireless sensor in your system has a 9-volt or 3-volt battery. The system detects a lowbattery in any wireless sensor, including smoke detectors, the optional personal emergencytransmitter, and the optional portable wireless keypad. (A low battery in a portable wirelesskeypad or keyfob is detected as soon as one of its keys is pressed, and the wired keypad willdisplay “00”.)Alkaline batteries provide a minimum of 1 year of operation, and in most units and applications,provide 2–4 years of service. 3-volt lithium batteries provide up to 4 or more years of operation.Actual battery life will depend on the environment in which the sensor is used, the number ofsignals 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 variations 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 displayed on thekeypad.In addition, a battery-operated smoke detector with a low battery also emits a single "chirp"sound approximately once every 20–30 seconds, identifying itself as the smoke detector withthe weak battery.Note: The low battery message comes on as a warning that battery replacement in indicatedsensor(s) is due within 30 days. In the meantime, a sensor causing a low battery indication isstill fully operational.Important: Use only batteries recommended by your installer as replacement.