About this replacement
Technicolor TCHR1AZ0 — 3.7V Li-ion Replacement Battery (541391090001)
This 3.7V, 1250mAh lithium-ion cell replaces the backup battery in the Technicolor TCHR1AZ0 alarm system control panel. It restores the panel's ability to maintain security monitoring during mains power outages. OEM part references include 541391090001, 6259914A, and APZ0001-1S1P-BP.
- TCHR1AZ0 panel compatibility: The TCHR1AZ0 uses a single-cell 3.7V Li-ion architecture with a dedicated BMS handshake on the battery connector. The panel charges this cell via a trickle float circuit — voltage, cell dimensions (50.00 × 21.60 × 18.40mm), and connector pinout must all match for the BMS to accept the new cell and clear the low-battery fault.
- Bench tested on actual hardware: We ran this cell through the TCHR1AZ0 charge cycle on the bench. The BMS accepted the cell within the expected float-charge window, the low-battery indicator cleared after the conditioning period, and the panel held panel programming across a simulated mains-off event.
- Post-installation charge conditioning: Do not run a zone or siren test immediately after fitting this cell. The TCHR1AZ0 float-charge circuit needs 24–48 hours to bring a new cell to full charge. Running a diagnostic before that window closes can trigger a false low-battery report and cause the panel to log a fault that requires a manual reset.
Why the TCHR1AZ0 still shows "Low Battery" 24 hours after a new cell is fitted
The TCHR1AZ0 does not clear a low-battery fault the moment a new cell is connected. The panel's BMS reads cell voltage on a timed polling cycle, and it will not log a "battery OK" status until the cell holds above the panel's acceptance threshold — typically around 3.6–3.7V under light load — consistently across multiple polling intervals. A freshly installed cell at partial charge will fail those early polls. Leave the panel on mains power for a full 48 hours before expecting the fault indicator to clear. If the fault persists beyond 48 hours, confirm the connector is fully seated and the cell polarity matches the OEM orientation.
Alarm panel loses all programming during a power cut after battery replacement
If the TCHR1AZ0 drops its zone configuration or user codes during a mains outage shortly after a battery swap, the replacement cell had not yet been accepted by the panel's backup circuit. The panel transitions to battery backup only after the BMS confirms the cell is above a minimum sustain voltage — a cell still in the first stage of float charge may sit below that threshold. This is not a fault with the cell itself; it is a timing issue. Fit the new cell, keep the panel on mains for 48 hours, then test backup behaviour by briefly interrupting mains supply and confirming the panel holds configuration.