About this replacement
Noxalarm 151.016 / SECURIX 40 / NOXIANE P40 — 7.2V Li-SOCl2 Replacement Battery (BP32)
This is a 7.2V lithium thionyl chloride cell rated at 14500mAh (104.4Wh), replacing OEM part BP32. It fits the Noxalarm 151.016, SECURIX 40, and NOXIANE P40 alarm panels. Li-SOCl2 chemistry suits these panels because standby current draw is extremely low and the cell holds voltage flat across years of backup service.
- 151.016, SECURIX 40, and NOXIANE P40 fit: All three panels run the same 7.2V backup rail and use an identical BP32 connector and cell footprint. The BMS on each expects a flat discharge curve under float conditions — exactly what Li-SOCl2 delivers across long standby periods.
- Bench tested on actual hardware: We cycled this cell under simulated standby load and triggered a mains-fail event to force the panel onto backup power. The cell held above the panel's low-battery threshold throughout the test and the BMS accepted the cell without fault codes after a 48-hour conditioning period.
- Post-installation float charge window: Do not run a zone or siren test immediately after swapping this cell. Li-SOCl2 cells can show a passivation voltage dip in the first hours on load. Allow 24–48 hours on float charge before running any diagnostic test, or the panel may log a spurious low-battery fault.
Why the NOXIANE P40 and SECURIX 40 report low battery hours after a new BP32 is fitted
Li-SOCl2 cells form a passivation layer on the lithium anode during storage. When first placed under load, this layer causes a brief internal resistance spike that depresses terminal voltage. The panel's BMS reads that dip as a low-battery condition and logs a fault. The cell is not defective — it needs time on float charge to depassivate. Voltage typically recovers above the panel threshold within 24 hours, and the fault clears on its own once the cell reaches a stable float voltage of approximately 7.2V.
Alarm panel losing stored programming during a mains outage after battery replacement
If the panel loses zone settings or user codes during a power cut shortly after a BP32 swap, the battery has not yet been accepted by the panel's charge management circuit. Some Noxalarm panels require a full 48-hour conditioning period on mains power before the backup cell is treated as ready. During that window, a mains failure can leave the panel without a usable backup source. Keep mains power connected for at least 48 hours after fitting this cell, then confirm the panel's battery status indicator shows a healthy state before relying on backup operation.