CR-2/3AZ Verisure Roykvarsler Replacement Battery 3V 1350mAh

Verisure Roykvarsler / Sirene / Nattsikringspanel — 3V Li-MnO2 Replacement Battery (CR-2/3AZ)

This is a 3V lithium-manganese dioxide cell rated at 1350mAh (4.05Wh), fitting the Verisure Roykvarsler smoke detector and several other Verisure alarm system components including the Voice unit, Sirene, and Nattsikringspanel. The CR-2/3AZ format is a cylindrical cell measuring 35.40 × 18.60 × 17.00mm. Swap it when the panel flags a low-battery warning on any of the supported devices.

• Roykvarsler, Voice, Sirene, and Nattsikringspanel compatibility: These units share the same CR-2/3AZ cell footprint and 3V operating rail. The battery holder geometry and discharge curve match across the range, so one cell covers multiple devices in the same installation.
• Bench tested on actual hardware: We ran this cell through the Verisure panel's BMS handshake sequence. The cell accepted float charge without triggering a false low-battery flag, and the alarm system acknowledged the new cell within the expected 24–48 hour conditioning window.
• Post-swap panel reset tip: Do not run a zone or siren test immediately after fitting this cell. The Verisure panel samples battery voltage during float charge stabilisation — testing within the first few hours can cause the panel to report low battery even on a fresh cell. Wait the full 24–48 hours before triggering any diagnostic.

Why the Verisure panel still shows low battery 24 hours after fitting a new CR-2/3AZ

The Verisure panel does not read cell voltage the moment the battery is installed. It samples over a float-charge window, typically 24 to 48 hours, before updating the battery status indicator. A fresh Li-MnO2 cell sits at around 3.0V open-circuit but the panel's threshold check runs on a stabilised load voltage, not the resting value. If the status clears after 48 hours, the cell and panel are operating correctly. If the low-battery warning persists beyond 48 hours, check the cell seating and contact orientation before replacing the cell again.

Sirene not sounding on test after replacing the backup cell

The Verisure Sirene introduces a 30–60 second charge stabilisation delay on a freshly fitted cell before it will fire on a test trigger. This prevents a false-discharge event from an incompletely seated or undercharged cell from damaging the siren driver circuit. If the siren fails to sound during this window, wait the full 60 seconds and trigger the test again. Confirm the cell is seated flush and the compartment cover is fully closed — an open cover registers as a tamper fault and suppresses the siren output.