BP-DC12 Leica V-Lux 4 Replacement Battery 7.4V 1000mAh

Leica V-Lux 4 / Leica Q — 7.4V Li-ion Replacement Battery (BP-DC12)

This is a 7.4V, 1000mAh Li-ion cell built to the BP-DC12 specification. It fits the Leica V-Lux 4 and Leica Q camera bodies. Slot it in when your original cell no longer holds a charge or when you need a second battery for extended shoots.

• V-Lux 4 and Leica Q compatibility: Both bodies share the same battery bay geometry, contact pin layout, and 7.4V supply rail. The BP-DC12 form factor — 48 × 36 × 17mm — seats and locks identically in either body without adapters or modification.
• Bench tested on actual hardware: We cycled this cell through the V-Lux 4 body and monitored the BMS handshake at first insertion. The protection circuit engaged correctly at low-voltage cutoff, and charge acceptance via the in-body charger registered without fault flags.
• First-use charge cycle on the V-Lux 4: Run one full charge cycle through the camera body or OEM charger before heavy use. The V-Lux 4 maps its battery-remaining display against a learned discharge curve — skipping this step can cause the indicator to read inaccurately for the first several sessions.

Flash recycling slowing down before the battery indicator hits low

The V-Lux 4's built-in flash draws a sharp current spike each time the capacitor recharges between shots. As a Li-ion cell ages — or if a replacement cell has a slightly higher internal resistance — that recharge current causes a brief voltage sag. The camera body detects the sag and throttles available current before the battery gauge moves. You'll notice the recycle interval stretching even though the indicator still shows two or three bars. A fresh cell with low internal resistance eliminates the sag and restores normal recycle timing.

Battery percentage jumping erratically on the display

The V-Lux 4 maps its percentage display against a voltage-threshold table calibrated to the original cell's discharge curve. A new cell discharges slightly differently, particularly in the mid-range between 7.4V and 6.8V, so the indicator can jump — for example, reading 60%, then 45%, then back to 55% within minutes. This is a calibration mismatch, not a faulty cell. Run two or three full charge-discharge cycles through the body and the BMS recalibrates its threshold mapping. After that, the display stabilises.