Fujifilm NP-40 FinePix 455 Zoom Compatible Battery 3.7V 850mAh

Fujifilm FinePix F455 / 455 Zoom Series — 3.7V Li-ion Replacement Battery (NP-40)

This is a 3.7V, 850mAh Li-ion replacement for the Fujifilm NP-40 and NP-40N battery cells. It fits the FinePix 455 Zoom, F402, F455, F460, and 23 additional FinePix compact models. Same voltage, same form factor, same connector as the original cell.

• FinePix compact platform fit: These models share a common 3.7V single-cell architecture with a standardised NP-40 footprint. The connector pinout and BMS communication protocol are identical across the range, so one cell covers all listed models without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on FinePix hardware. The BMS accepted the cell, reported charge state correctly, and flash recycling held steady across repeated bursts without triggering low-voltage cutoff prematurely.
• First-install charge cycle on FinePix bodies: Insert the cell and run a full charge inside the camera body or OEM charger before your first shoot. Some FinePix BMS firmware maps the battery-remaining indicator to a discharge curve it calibrates on that first cycle — skipping this step can cause erratic percentage readings.

Flash recycling slowing down before the battery indicator drops

The FinePix flash capacitor pulls a sharp current spike each time it recharges between shots. Near the end of a discharge cycle, internal cell resistance rises and the capacitor takes longer to reach full charge — even if the battery indicator still shows two bars. This shows up as a longer pause between shots in burst or event shooting. It is not a fault in the replacement cell; it is normal electrochemical behaviour as the cell approaches 3.0V cutoff. If recycling lag becomes noticeable, charge the cell before the next session rather than waiting for the low-battery warning.

Battery percentage jumping or reading full immediately after install

The FinePix fuel gauge maps voltage thresholds to a discharge curve it learned from the previous cell. A new cell with a slightly different internal resistance profile can land at an unexpected voltage point during the first partial discharge, causing the display to jump — or to read 100% and then drop sharply. One full charge-discharge cycle inside the camera body resets the mapping. After that cycle, the percentage display tracks the actual cell state correctly. If the jumping persists beyond two full cycles, check that the battery contacts on the door are clean and making firm contact.