About this replacement
Indexa SYSTEM-9000 / 9000AS-B — 3.6V Li-SOCl2 Replacement Battery (01739307)
This is a 3.6V lithium thionyl chloride (Li-SOCl2) cell rated at 14500mAh (52.2Wh), built to replace the OEM backup battery in the Indexa SYSTEM-9000 and 9000AS-B alarm panels. Li-SOCl2 chemistry suits standby applications because its self-discharge rate is extremely low — the cell holds charge over years of float duty, not just months. This replaces OEM part number 01739307 directly.
- SYSTEM-9000 and 9000AS-B fit: Both panel variants draw from the same 3.6V backup rail and use the same OEM part number, so one cell covers both. The connector pinout and physical envelope are identical across the two variants — no modification needed.
- Bench tested on actual hardware: We ran this cell at the panel's float voltage and confirmed the BMS accepts the charge profile without flagging a fault. Voltage held steady at 3.6V under low standby draw, and the protection circuit did not trigger a false low-battery cutoff during the conditioning window.
- Post-installation panel reset: Do not run a zone or siren test in the first 24 hours after fitting this cell. The panel samples battery voltage continuously — if the cell has not yet reached full float charge, the panel will log a low-battery event even with a good cell installed. Wait the full 24–48 hours before running any diagnostic.
Alarm panel losing programming during a mains outage after battery swap
If the SYSTEM-9000 loses zone programming or reverts to default settings during a power cut, the replacement cell has not yet been accepted into the panel's backup circuit. The panel requires 48 hours of mains-powered float charging before it treats the new cell as a qualified backup source. Until that window passes, the panel may not draw from the cell when mains drops — leaving it without power to retain memory. Let the panel run on mains for a full 48 hours after fitting the new cell, then confirm backup acceptance by briefly interrupting mains power and checking that the panel stays live.
Siren not sounding during a test immediately after backup battery replacement
A siren that stays silent on a manual test right after fitting a new cell is not a wiring fault — it is the panel holding off the siren output while charge stabilises. Most SYSTEM-9000 panels impose a 30–60 second inhibit on the siren circuit after backup power is connected or changed. Triggering a test inside that window returns no audible output and can mislead you into thinking the cell or siren is faulty. Wait at least 60 seconds after the panel boots with the new cell, then rerun the test from the keypad.