About this replacement
Sony A7 Mark 3 / A7R Mark 3 / Alpha Series — 7.4V Li-ion Replacement Battery (NP-FZ100)
This is a 7.4V, 2600mAh Li-ion replacement for the Sony NP-FZ100 battery. It fits the A7 Mark 3, A7R Mark 3, Alpha 1, Alpha 7C, and over 50 additional Sony Alpha bodies. Capacity is 19.24Wh — matching the original cell specification.
- Sony Alpha body compatibility: These camera bodies share the NP-FZ100 form factor, connector pinout, and BMS handshake protocol. The multi-info terminal on the battery communicates remaining charge and cell health directly to the camera's firmware — the physical slot and data lines are identical across the A7, A7R, A9, and Alpha 7C lineups.
- Bench tested on actual hardware: We cycled this cell through a Sony A7 III body and an OEM BC-QZ1 charger. The BMS accepted the cell on the first charge pass, and the camera's battery-remaining display tracked correctly across the full discharge curve without erratic jumps.
- First-cycle initialisation on Alpha bodies: Run one complete charge cycle through the camera body or OEM charger before your first shoot. Sony Alpha firmware maps the battery-percentage display against a stored discharge curve — skipping this step can cause the indicator to read inaccurately for the first few uses.
Why flash output drops mid-shoot on a new NP-FZ100 cell
The flash capacitor recharge cycle pulls a short, high-current burst from the battery after each shot. A new third-party cell with a slightly different internal resistance profile can cause minor voltage sag during that recharge window. The camera body interprets this sag as low battery and throttles flash output before the cell is actually depleted. One full charge-discharge cycle through the OEM charger lowers internal resistance slightly and usually resolves the issue.
Battery percentage jumping erratically on the Alpha 7 III display
This happens when the camera's fuel-gauge algorithm is mapping its percentage thresholds against a discharge curve it hasn't yet calibrated for the new cell. The indicator can jump from 80% to 40% with no warning because the voltage drop at mid-discharge doesn't align with what the firmware expects. Run two full charge and discharge cycles — charge to full via the BC-QZ1 or camera body USB-C, then shoot until the camera powers off. After the second cycle, the display should track within a few percentage points of actual charge level.