About this replacement
Casio Exilim EX-V8SR / EX-V7 Series — 3.7V Li-ion Replacement Battery (NP-50)
This 3.7V, 950mAh Li-ion cell replaces the Casio NP-50 battery in the Exilim EX-V8SR, EX-V8, EX-V7, and EX-V7SR compact digital cameras. It matches the original form factor at 70.10 × 23.45 × 6.50mm and slots into the camera body without modification. Capacity figure is 950mAh (3.52Wh) — taken from the cell specification, not estimated.
- EX-V7 and EX-V8 series compatibility: All four models in this fit list share the same NP-50 battery bay, voltage rail, and connector pinout. The BMS handshake across this series reads the same cell identification, so one replacement cell covers the full group.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the EX-V8 platform. The BMS accepted the cell without error flags, and the protection circuit triggered correctly at the low-voltage cutoff threshold — no runaway discharge observed.
- First-use charge cycle on EX-V8SR: Insert the new cell and charge it fully inside the camera body or OEM charger before your first shoot. The Exilim BMS maps its battery-remaining display to a discharge curve it calibrates on the first full cycle — skipping this step causes the indicator to read inaccurately for several sessions.
Flash recycling lag on a new NP-50 cell near the end of charge
The Exilim EX-V8SR flash capacitor draws a sharp recharge current after each shot. When the cell voltage drops toward the lower end of its discharge curve — typically below 3.5V under load — that capacitor recharge current causes a brief voltage sag. The camera's processor detects the sag and slows the recycling cycle to protect the cell. You'll notice the flash-ready indicator taking longer between shots even though the battery indicator still shows partial charge. This is normal BMS behaviour, not a fault — it means the cell is approaching its cutoff window.
Battery percentage jumping erratically on the EX-V8SR display
The Exilim BMS maps its on-screen percentage to a voltage-threshold table calibrated for the original NP-50 discharge curve. A replacement cell with a slightly different internal resistance will follow a marginally different voltage curve under load, so the displayed percentage can jump — for example, from 60% to 30% in a single burst of shots. This is a display calibration mismatch, not a capacity fault. Run two full charge-discharge cycles through the camera body and the BMS will re-map its thresholds to the new cell's actual curve.