About this replacement
Fujifilm X-T4 / GFX100S / X-H2S — 7.4V Li-ion Replacement Battery (NP-W235)
This is a 7.4V, 2250mAh (16.65Wh) Li-ion cell built to the NP-W235 specification. It fits the Fujifilm X-T4, GFX100S, GFX50S II, and X-H2S mirrorless cameras. The cell slots into the same battery compartment and communicates with the camera's BMS through the same contact arrangement as the original.
- X-T4, GFX100S, GFX50S II, X-H2S compatibility: All four bodies share the NP-W235 footprint, voltage rail, and three-pin contact layout. The BMS on each body reads cell state-of-charge over the same data line, so one cell works across all four platforms without any adapter.
- Bench tested on actual hardware: We ran this cell in an X-T4 body through a full discharge cycle with continuous autofocus, 4K video recording, and EVF active. The BMS accepted the cell on first install and held a stable voltage curve through to the low-battery cutoff threshold.
- First-use charge cycle on GFX bodies: GFX100S and GFX50S II bodies occasionally map battery-remaining percentage inaccurately on a new cell until one full charge cycle is completed inside the camera body itself — not an external charger. Run a full in-body charge before the first shoot to calibrate the indicator correctly.
Why the X-T4 battery percentage drops sharply during 4K recording
The X-T4 pulls current simultaneously from the sensor, the IBIS motor, the processor, and the EVF during 4K capture. That combined draw creates a voltage sag that the camera's indicator reads as a lower state-of-charge than the cell actually holds. The percentage can jump down several points under load, then partially recover when recording stops. This is a voltage-sag read from the BMS — not cell failure.
Camera displaying "incompatible battery" on a freshly installed NP-W235 replacement
Fujifilm bodies run an authentication handshake with the battery on power-on. A new cell with a fully discharged or uninitialized BMS can fail that check and trigger the incompatible warning. Remove the battery, reinsert it, and power the camera on again — most bodies clear the error on the second attempt. If the message persists, place the cell in the camera and charge it in-body to at least 8.0V before retrying.