Leica BP-DC6-E Replacement Battery 3.7V 1050mAh Li-ion

Leica C-LUX 2 / C-LUX 3 — 3.7V Li-ion Replacement Battery (BP-DC6-E)

This is a 3.7V, 1050mAh Li-ion replacement cell for the Leica C-LUX 2 and C-LUX 3 compact digital cameras. It replaces OEM part numbers BP-DC6-E, BP-DC6-U, BP-DC6, and BP-DC6-J. Same dimensions at 40.60 × 36.26 × 7.10mm — fits the battery compartment without modification.

• C-LUX 2 and C-LUX 3 shared platform: Both models run the same 3.7V rail and use an identical BP-DC6 footprint. The battery management system on each body uses the same voltage thresholds and charge termination logic, so one cell covers both cameras without any modification to settings or connectors.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a C-LUX body. The BMS accepted the cell, charge termination triggered correctly at full capacity, and the protection circuit tripped as expected at the low-voltage cutoff — no false cutoffs mid-cycle.
• First-cycle initialisation on C-LUX bodies: On the C-LUX 2 and C-LUX 3, run the first full charge inside the camera body or the OEM charger before any shooting. The BMS maps its battery-remaining display to the cell's discharge curve during that first cycle — skipping it causes the indicator to read erratically from the start.

Battery percentage jumping erratically on the C-LUX display

The C-LUX series maps its fuel gauge to a discharge curve calibrated against the OEM cell. A new third-party cell has a slightly different discharge profile, so the indicator can jump — showing 60%, then 80%, then 40% within a few shots. This is not a cell fault. Running two or three full charge and discharge cycles allows the BMS to re-map its thresholds to the new cell's actual curve. After that, the indicator stabilises.

C-LUX showing a dead-battery icon on a cell that still has charge

This happens when the camera body's low-voltage cutoff triggers before the cell is actually depleted — common on first install of a replacement cell that hasn't been initialised. The BMS reads resting voltage rather than load voltage, and a new cell can sit slightly outside the expected threshold range until it's been cycled once. Remove the battery, reinsert it, and charge fully in the camera body to 4.2V before shooting. That single charge cycle usually clears the false cutoff on subsequent use.