About this replacement
Abus Secvest Series — 7.4V Li-Polymer Replacement Battery (FUBT50000)
This 7.4V 2400mAh Li-Polymer cell replaces the internal backup battery in the Abus Secvest wireless alarm control panel. It fits the FUAA50000, FUAA50100, and FUAA50500 panel variants, along with three additional Secvest models. When mains power drops, this cell keeps the panel alive — maintaining sensor communication, zone monitoring, and emergency alerts.
- Secvest panel compatibility: All listed Secvest variants share the same 7.4V Li-Polymer cell format, connector pinout, and BMS communication protocol. The panel's charge management circuit charges and monitors this cell directly — no adapter or rewiring needed.
- Bench tested on actual hardware: We ran this cell through charge acceptance and BMS handshake checks on the Secvest platform. The panel recognised the battery, began float charging without fault codes, and held voltage within spec across multiple charge cycles.
- Post-installation charge window: Do not run a zone or siren test immediately after fitting this cell. The Secvest panel needs 24 to 48 hours on float charge before the battery reaches full capacity. Running diagnostics too early will trigger a low-battery report even from a good cell.
Alarm panel showing low battery hours after installing a new cell
The Secvest panel samples battery voltage during standby and compares it against a threshold stored in firmware. A freshly installed Li-Polymer cell ships at a storage charge — typically 3.7V to 3.85V per cell — which sits below the panel's "full" threshold of around 8.2V to 8.4V. The panel reads this correctly as low and flags it. This is not a fault with the battery. Leave the panel on mains power for 48 hours and the charge controller will bring the cell up to float voltage, clearing the warning.
Panel loses programming during a power outage after fitting a new battery
If a mains outage occurs before the new cell has completed its initial charge cycle, the battery cannot sustain the panel's operating voltage long enough to hold RAM and configuration data. The Secvest panel requires a stable backup voltage above approximately 7.0V to retain programming. A partially charged cell can drop below this threshold within minutes of a power cut. Allow the full 48-hour float charge period to complete before the panel is exposed to any mains interruption.