About this replacement
Somfy Door Keeper Smart Connected — 7.4V Li-ion Replacement Battery (BL7812)
This is a 7.4V, 2750mAh Li-ion replacement battery for the Somfy Door Keeper Smart Connected lock (model 1241386). It restores power to the lock's motor, Bluetooth radio, and access control electronics. Fits the Door Keeper Lock and Door Keeper Smart Connected ranges using the BL7812 battery.
- Door Keeper Smart Connected compatibility: These lock variants share the same 7.4V power architecture, BL7812 connector format, and BMS communication protocol. Swapping a depleted original for this unit keeps the lock's control board online without triggering fault states.
- Bench tested on actual hardware: We ran this battery through charge and discharge cycles on the BL7812 platform. The BMS held voltage within the lock's operating band and cut off correctly at the low-voltage threshold — no false trips or undervoltage faults during testing.
- Post-swap access verification: After fitting this battery, test every access method — keypad, Bluetooth app, and keycard — before closing the door. The Door Keeper Smart Connected performs a firmware handshake after power interruption, and some access methods won't accept credentials until that handshake completes.
Why the Door Keeper Smart Connected goes unresponsive after a battery swap
The Door Keeper Smart Connected runs a startup sequence when power is restored. During this sequence, the lock's control board re-initialises the motor driver, Bluetooth radio, and access credential store. If you test the lock before this sequence finishes — typically within the first 20–30 seconds after battery insertion — the lock will not respond to any input. Wait for the lock to emit its ready signal (usually a beep or LED flash) before testing access.
Low battery warning showing immediately after fitting a new BL7812
The Door Keeper Smart Connected reads battery state through the BMS voltage line, not a fuel gauge IC. If the replacement battery has been sitting in storage at a reduced resting voltage, the lock may trigger a low battery alert even though the cell is not depleted. Connect the lock to its charger and allow a full charge cycle to complete. Once the BMS reports a full resting voltage — nominally 8.4V for a 7.4V Li-ion pack — the alert will clear and the lock will read battery state accurately.