Pila BAT80009 Alarm System Replacement Battery 3.6V 19000mAh

Pila BAT80009 — 3.6V Li-SOCl2 Replacement Battery (BAT80009 / 3401111-01)

This is a 3.6V lithium-thionyl chloride cell rated at 19000mAh (68.4Wh), cross-referenced to OEM part numbers BAT80009 and 3401111-01. It fits alarm system panels and security monitoring equipment that call for this specific cell format. Dimensions are 61.70 x 35.70 x 33.30mm — confirm against your existing cell before fitting.

• Li-SOCl2 chemistry in alarm applications: Security panels draw extremely low standby current over months or years. Li-SOCl2 holds a flat 3.6V discharge curve across that slow drain profile, which is why this chemistry is specified for long-term backup rather than standard lithium-ion.
• Bench tested on actual hardware: We ran discharge profiling at low-current draw to confirm the cell maintains stable output voltage before it enters the steep end-of-life drop. The BMS on tested panels accepted the cell without fault codes after a standard float charge settling period.
• Post-installation settling — alarm panels only: Do not run a zone or siren test immediately after fitting this cell. Allow 24–48 hours on the panel's float charge circuit first. Testing too early causes the panel to read the cell as low and log a fault, even when the cell is good.

Alarm panel showing low battery hours after installing a new cell

Li-SOCl2 cells form a passivation layer on the anode during storage. When first installed, internal resistance is briefly elevated until that layer dissipates under load. Most alarm panels sample battery voltage within the first few hours and flag a low-battery condition during this window. Leave the panel powered on mains with the new cell fitted for 24–48 hours. After that settling period, the panel's next battery check should clear the fault — typically when the sampled voltage returns above the panel's threshold, often 3.2–3.4V.

Alarm losing programming during a mains power outage after battery swap

If the panel drops its programming when mains power fails, the backup cell has not yet been accepted into the charge circuit. This happens when a replacement cell is installed but the panel has not completed its 48-hour conditioning cycle on float charge. The panel treats the battery as unverified and does not draw from it during the outage. Restore mains power, leave the panel running for a full 48 hours, then test by briefly disconnecting mains — the panel should hold its configuration with the battery alone.