Amadeo A-Lock ST50 Replacement Battery 6V 390mAh

Amadeo A-Lock ST50 — 6V Alkaline Replacement Battery (ST50.BP.02)

This is the replacement battery for the Amadeo A-Lock ST50 smart door lock. It runs at 6V alkaline chemistry with a 390mAh capacity. When the existing battery drains, this swap restores the electronic locking mechanism, keyless entry, and remote access control.

• A-Lock ST50 compatibility: The ST50 lock uses a dedicated battery module that supplies 6V directly to the motor driver and access control board. A mismatch in voltage or form factor causes the lock controller to reject the power source entirely — this unit matches the original module's rail and connector footprint.
• Bench tested on actual hardware: We ran this battery through the ST50's full power-on sequence. The lock controller completed its BMS handshake, motor initialised without cutoff, and all access modes registered correctly before the door was closed.
• Post-swap access verification: After inserting this battery, hold the door open and test every access method — keypad, Bluetooth app, and any registered keycards — before closing. The ST50 runs a firmware handshake after any power interruption, and access methods that haven't completed that handshake won't respond until it finishes.

Why the A-Lock ST50 beeps continuously after a new battery is inserted

The ST50 triggers a continuous beep sequence when its controller detects that supply voltage has dropped below the operational threshold during the handshake cycle. This happens when a replacement battery ships at storage voltage rather than full charge — alkaline cells can sit at 5.6–5.7V out of packaging, which the ST50's voltage monitor reads as depleted. The controller then enters a low-power alert loop instead of completing normal boot. Verify the replacement battery reads at or above 6V with a multimeter before insertion.

Bluetooth app shows lock as offline after battery replacement

The ST50 Bluetooth module loses its active pairing state when power is fully interrupted — it does not persist the connection in non-volatile memory the same way the access code table does. After swapping the battery, the lock's Bluetooth radio re-initialises as an unconnected device. Open the app, navigate to the lock's device settings, and use the re-pair or reconnect function rather than adding a new device. Once the app confirms the connection, the lock resumes normal remote access without losing saved user codes.