About this replacement
Fujifilm FinePix HS30EXR / X-Pro1 Series — 7.4V Li-ion Replacement Battery (NP-W126S)
This 7.4V, 1000mAh Li-ion cell replaces the Fujifilm NP-W126S and NP-W126 in the FinePix HS30EXR, HS33EXR, X-Pro1, and over 50 additional Fujifilm bodies. It delivers the same voltage rail the camera's BMS expects, keeping exposure metering, EVF, and image stabilisation running at full draw. Dimensions are 47.10 × 36.20 × 15.90mm — a direct physical match to the OEM cell.
- HS30EXR / HS33EXR and X-Pro1 platform fit: These bodies share the same NP-W126 battery bay, connector pinout, and BMS communication protocol — which is why one cell covers both the FinePix bridge camera line and the X-series mirrorless bodies. The 7.4V nominal rail is consistent across all listed models.
- Bench tested on actual hardware: We cycled this cell on an HS30EXR body and an X-Pro1. The BMS accepted the cell on both, negotiated charge termination cleanly, and the battery indicator stabilised after one full in-camera charge cycle. No BMS rejection flags appeared during testing.
- First-install charge cycle on HS30EXR: Run the first full charge inside the camera body or an OEM Fujifilm charger before heavy shooting. The HS30EXR maps its battery-remaining display against a known discharge curve — skipping this step can cause the indicator to read inaccurately for the first several sessions.
Why the HS30EXR battery indicator jumps erratically after a new cell is installed
The HS30EXR uses a voltage-threshold method to estimate remaining charge — it maps a fixed discharge curve against the cell voltage it reads in real time. A new Li-ion cell has a slightly different internal resistance profile than a broken-in OEM cell, so the voltage readings at shallow discharge don't align with the thresholds the camera expects. This causes the indicator to jump — often showing three bars, then one, then two — until the cell has been through two or three full charge and discharge cycles. After that calibration period, the display stabilises. If it doesn't settle by cycle three, confirm the charge termination voltage is reaching 8.35–8.40V.
Camera body shows "no battery" or refuses to power on with replacement cell inserted
Fujifilm's X-series and FinePix bridge bodies perform a BMS handshake on power-on — if the cell voltage is below the camera's wake threshold (typically under 6.8V), the body rejects the cell entirely and displays a no-battery error even with a physically installed pack. This can happen if the replacement cell shipped in a deep-discharged state after extended storage. Place the cell in a Fujifilm-compatible external charger for 15–20 minutes to raise it above 7.0V, then reinsert it into the camera. The body should recognise it and allow a full charge from there.