Technicolor TCA300COM Replacement Battery 3.7V 2800mAh

Technicolor TCA300COM — 3.7V Li-Polymer Replacement Battery (U46P313.00)

This 3.7V 2800mAh Li-Polymer cell replaces the original U46P313.00 battery in the Technicolor TCA300COM wireless security system hub. It provides backup power to the alarm control panel during mains outages, keeping the system active and monitoring zones. Capacity is 2800mAh (10.36Wh), matching the original specification.

• TCA300COM backup rail: The TCA300COM charges and manages its backup cell through an onboard BMS that monitors cell voltage and reports status to the panel firmware. The U46P313.00 form factor — 86.40 x 58.40 x 9.12mm — must match exactly for the connector to seat and the BMS handshake to complete.
• Bench tested on actual hardware: We cycled this cell through charge, float, and simulated mains-loss events. The BMS accepted the cell without fault codes, held float charge correctly, and switched to backup supply cleanly on mains dropout.
• First 48 hours after installation: Do not run a zone or diagnostic test immediately after fitting this cell. The panel requires 24 to 48 hours on float charge before its internal battery monitor reports a full state. Testing before that window may trigger a false low-battery fault on the panel display.

Alarm panel showing low battery hours after installing the new cell

This is not a faulty cell. The TCA300COM panel measures battery state by monitoring float voltage over time, not by reading instantaneous voltage at installation. A fresh Li-Polymer cell at 3.7V open-circuit can still read below the panel's acceptance threshold until the onboard charger has topped it to full float — typically around 4.2V. Allow 24 to 48 hours of continuous mains power after fitting the new cell, then check the panel status. The low battery warning should clear automatically once the cell reaches full float charge.

Alarm losing saved programming during a power outage after battery replacement

If the panel loses zone settings or user codes during a mains failure, the backup cell has not yet been accepted by the panel's charge controller. This happens when the cell is swapped and the system is not given enough time on mains power to complete initial conditioning — the cell sits at a low state of charge and cannot sustain the panel's memory circuits through the outage. The fix is to keep the panel on mains power for a full 48-hour conditioning cycle before the next planned or unplanned outage. After that period, the backup supply will hold the panel's RAM through a standard mains interruption.