About this replacement
Commpact Secuself Control Panel — 4.8V Ni-MH Replacement Battery (BT3021)
This 4.8V, 1500mAh Ni-MH battery replaces the backup cell in the Commpact Secuself Control Panel. It fits panels using OEM part numbers BT3021 and BT1348. The battery keeps the alarm system active when mains power drops.
- Secuself panel compatibility: The Secuself Control Panel uses a 4.8V Ni-MH pack with a specific connector and charge management circuit. This cell matches that voltage rail and connector profile, so the panel's charge circuit accepts it without modification.
- Bench tested on actual hardware: We ran this cell through the panel's float charge cycle and confirmed the BMS accepted the charge handshake correctly. Charge acceptance was normal and the low-battery indicator cleared within the expected window.
- Post-installation wait before testing: Do not run a zone or siren test immediately after swapping this cell. Allow 24–48 hours on float charge before triggering a diagnostic. Running a test too early can cause the panel to flag a low-battery fault even though the cell is functioning correctly.
Alarm panel showing low battery hours after installing new cell
The Secuself panel monitors backup battery voltage continuously. A freshly installed Ni-MH cell starts below the panel's acceptance threshold and needs time on float charge before it reads as full. The panel's charge circuit brings the cell up gradually — this is normal Ni-MH behaviour, not a fault. Give the cell a full 24–48 hours on mains power before concluding there is a problem.
Alarm loses programming during a mains outage after battery replacement
If the panel loses zone settings or user codes during a power cut shortly after a battery swap, the replacement cell had not yet reached sufficient charge to hold the panel's memory rail. The Secuself panel draws a small but steady current to retain programming — a cell below roughly 4.5V under load cannot sustain this. Install the new cell, restore mains power, and allow 48 hours of conditioning before testing with a deliberate outage.