Visonic PowerMaster 360R Replacement Battery 3.7V 3000mAh

Visonic PowerMaster 360R — 3.7V Li-Polymer Replacement Battery (103-306545)

This 3.7V 3000mAh Li-Polymer cell replaces the internal backup battery in the Visonic PowerMaster 360R wireless security panel. It matches OEM part number 103-306545 and supplies standby power during mains outages to keep the panel active, sensors connected, and alerts functional. Capacity is rated at 11.1Wh.

• PowerMaster 360R backup rail: The 360R uses a single Li-Polymer cell on a dedicated backup rail managed by the panel's onboard charge controller. The 3.7V nominal voltage and flat-pack form factor (67.50 × 63.60 × 5.00mm) must match exactly — the panel will reject cells with incorrect geometry or voltage profiles.
• Bench tested on actual hardware: We cycled this cell through the 360R's charge controller and confirmed the BMS accepted the cell without fault codes, held float charge correctly, and passed low-battery status clearance after a full conditioning period.
• Post-installation charge window: Do not run a zone or siren test immediately after swapping this cell. Allow 24–48 hours on mains power so the panel's charge controller can bring the cell to full float charge — triggering a diagnostic test before this window closes will cause the panel to report a false low-battery condition.

Alarm panel showing low battery hours after installing new cell

The PowerMaster 360R does not report battery status based on a spot voltage reading at the moment of installation. The panel's charge controller samples voltage against an internal threshold that only clears once the cell has reached a sustained float charge level — typically after 24 to 48 hours on mains power. Installing a fully charged cell still triggers this delay because the controller needs to verify stable charge acceptance over time, not just an initial voltage. If the low-battery warning persists past 48 hours with mains power confirmed, check the connector seating and inspect for a loose cell contact.

Panel loses stored programming during a mains power cut after new battery install

If a mains outage occurs within the first 48 hours after a battery swap, the 360R may not draw sufficient backup current from the new cell to hold programming in volatile memory — the cell has not yet completed its initial charge acceptance cycle. The panel treats an insufficiently charged backup cell as absent and defaults to a safe-state reset, which can wipe zone configurations and user codes. To avoid this, keep the panel on mains power for at least 48 hours before deliberately testing a power-cut scenario. After that conditioning period, restore power and re-enter any lost codes at the keypad.