How long will the backup battery keep the panel active if power is lost?
This is dependent on the the AMP-HOUR figure on the battery in the alarm panel, and the current being drawn while the system is set. The panel itself will be drawing about 100 to 200 Mili-amps, and the PIR’s will be using about 10 to 25mA each. Door magnets do not use any power, but add in any glass-break sensors. So, if your alarm panel load is 100mA plus the 15mA bell hold-off circuit, and 6 PIRS at 10mA (that is worst case with LED on, most run at 5mA) that totals 175mA), So, if you have a 4aH battery installed, that should provide 4,000 mA for one hour, or 175mA for a theoretical 22.9 HOURS. However, the voltage would drop to below the threshold to operate the electronics properly after about 11 hours. Always try to fit the largest capacity battery that will fit into the panel, to give the longest possible backup time.
