Many modern security systems use wireless technology for signaling between security devices. Installing battery powered wireless window/door sensors, motion detectors and keypads makes for a speedy and non-invasive installation. Section 4.7 has special requirements for wireless security systems. Section 4.7.2 provides details on using dry cell batteries as the sole power source of a wireless transmitter, but specific conditions must be followed. See requirements below.

Below is a sample of NFPA 731. For the complete section, see the actual NFPA 731 text at NFPA.ORG. Once there, click on the free access link to the latest edition of NFPA 731.

4.7 Special Requirements for Low-Power Radio (Wireless) Systems.

4.7.2 Power Supplies. A primary battery (dry cell) shall be permitted to be used as the sole power source of a low-power radio transmitter where all of the following conditions are met:

(1) Each transmitter serves only one device

(2) Each transmitter is individually identified at the receiver/ control unit

(3) The battery is capable of operating the low-power radio transmitter for not less than 1 year before the battery depletion threshold is reached

(4) A battery depletion signal is transmitted before the battery has been depleted to a level below that required to support alarm transmission for 7 additional days of nonalarm operation and incorporates the following:

(a) This signal is distinctive from alarm, supervisory, tamper, and trouble signals

(b) This signal visibly identifies the affected low-power radio transmitter

(c) This signal, when silenced, automatically re-sounds at least once every 4 hours

(5) Catastrophic (open or short) battery failure causes the following conditions:

(a) A trouble signal identifies the affected low-power radio transmitter at its receiver/control unit

(b) When silenced, the trouble signal automatically resounds at least once every 4 hours

(6) Any mode of failure of a primary battery in a low-power radio transmitter does not affect any other low-power radio transmitter