Leica BP-DC4 C-LUX1 Replacement Battery 3.7V 1150mAh

Leica C-LUX1 / D-LUX Series — 3.7V Li-ion Replacement Battery (BP-DC4)

This is a 3.7V, 1150mAh Li-ion replacement for the Leica BP-DC4 battery. It fits the C-LUX1, D-LUX2, D-LUX3, and D-LUX 4 compact cameras. The cell matches OEM voltage and capacity to keep the camera's metering, autofocus, and LCD functions running correctly.

• C-LUX1 and D-LUX platform fit: These four models share the same BP-DC4 form factor, contact layout, and 3.7V rail. The BMS in each body expects the same charge termination voltage, so one cell covers the entire range without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a D-LUX3 body. The BMS accepted the cell on first install, reported battery level correctly, and held charge termination at 4.2V as expected.
• First-use charge cycle on C-LUX1 and D-LUX bodies: Run one full charge inside the camera body or OEM charger before your first shoot. Some D-LUX BMS firmware maps battery-remaining percentage by learning the new cell's discharge curve during that initial cycle — skipping it can cause erratic indicator readings.

Why the D-LUX 4 battery indicator jumps during continuous shooting

The D-LUX 4 uses a voltage-threshold system to estimate remaining charge. During bursts or sustained LCD-on shooting, current draw spikes and momentarily drops cell voltage below a threshold, causing the indicator to step down suddenly. When the load eases, voltage recovers and the reading jumps back up. This is normal behaviour with any Li-ion cell — it does not mean the battery is faulty. After the first full charge cycle, the camera's firmware maps the new cell's discharge curve more accurately and the jumps reduce.

Camera body shows dead battery on a cell that still has charge

This happens when the BMS has not yet accepted the replacement cell's resting voltage as a valid starting point. The camera reads the open-circuit voltage against its internal map and flags it as depleted if the two don't match. Place the battery in the OEM charger or the camera body and run a full charge cycle to 4.2V. After one complete charge, the body recalibrates its reference and the indicator reads correctly from that point forward.