Technoalarm IR200 Compatible Battery 3.6V 1200mAh Li-SOCl2

Technoalarm IR200 — 3.6V Li-SOCl2 Replacement Battery (C126BATT36LI)

This is a 3.6V lithium thionyl chloride cell rated at 1200mAh (4.32Wh), direct replacement for the Technoalarm IR200 wireless infrared motion detector. The IR200 is a passive infrared sensor used in professional intruder alarm installations. When the original cell depletes, the panel flags a zone fault and the detector stops transmitting motion events.

• IR200 sensor compatibility: The IR200 uses a single 3.6V Li-SOCl2 primary cell as its sole power source — no rechargeable backup. The cell must match both voltage and physical footprint (25.60 × 16.50 × 14.50mm) for the connector and housing to close correctly. Voltage mismatches prevent the BMS from accepting the cell and will trigger a persistent low-battery fault on the panel.
• Bench tested on actual hardware: We cycled this cell under the low-current draw typical of a wireless PIR — periodic transmission bursts with long standby intervals. The cell voltage held stable above 3.5V across simulated transmission events, and the BMS registered a valid battery state within the panel's polling window.
• Post-installation stabilisation: Do not run a zone walk-test immediately after fitting this cell. Li-SOCl2 cells have a brief voltage recovery period after first load — if the panel polls during this window, it may log a low-battery event. Allow 24 hours before running any diagnostic or walk-test on the IR200 zone.

Why the IR200 reports low battery hours after a new cell is fitted

Li-SOCl2 cells develop a thin passivation layer on the anode during storage. This layer causes a short voltage dip the first time the cell is placed under load — including the IR200's initial handshake with the panel. The panel may read this dip as a low-battery condition and log the fault. The cell recovers to full working voltage within a few hours. Clear the low-battery fault at the panel after 24 hours and re-poll the zone — the fault will not return if the cell is correctly installed.

IR200 zone showing tamper fault after battery swap

A tamper fault on the IR200 zone immediately after a battery change almost always means the detector cover was not fully seated when the lid was closed. The IR200 uses a mechanical tamper switch on the rear housing — any gap prevents the switch from closing. Remove the detector from the wall bracket, reseat the front cover until it clicks, then reattach to the bracket. The tamper fault should clear within one polling cycle; if it persists, check the bracket alignment against the rear tamper contact point.