Voigtlander Virtus D5 NP-900 Replacement Battery 3.7V 600mAh

Voigtlander Virtus D5 Series — 3.7V Li-ion Replacement Battery (NP-900)

This is a 3.7V, 600mAh lithium-ion cell built to the NP-900 specification. It fits the Voigtlander Virtus D4, D5, D6, and D600 compact digital cameras. The cell powers the image sensor, autofocus motor, and processing unit across photo and video recording modes.

• Virtus D4 / D5 / D6 / D600 compatibility: These models share the same battery bay geometry, 3.7V rail, and NP-900 connector pinout. The BMS on each body reads cell voltage and temperature through the same contact pair, so one cell covers the full range without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Virtus D5 body. The BMS accepted the cell without error flags, regulated draw stayed within the 3.7V window, and the protection circuit tripped correctly at low-voltage cutoff.
• First-install charge cycle on Virtus bodies: Insert the cell and charge it fully through the camera body or the OEM charger before your first shoot. The Virtus BMS maps battery-remaining percentage against a discharge curve it calibrates on that first full cycle — skipping this step causes inaccurate charge indicators from the start.

Why the Virtus D5 battery indicator drops suddenly at around 30%

The Virtus body uses a voltage-threshold method to estimate remaining charge rather than a coulomb-counting circuit. Replacement cells have a slightly different discharge curve than the original OEM cell, so the thresholds the camera was calibrated against don't map cleanly to the new cell. The indicator holds steady, then steps down sharply when the voltage crosses a threshold point. Running one full charge-discharge cycle through the camera body lets the BMS recalibrate its reference point and smooths out the indicator behaviour.

Camera displaying "no battery" with a freshly installed NP-900 cell

This happens when the BMS authentication check doesn't complete on the first cold insertion — the camera sees the cell voltage but fails the handshake. Remove the cell, wait ten seconds, and reinsert it firmly so all three contact points seat flush. If the error persists, place the cell in the OEM charger until the charge light confirms acceptance, then transfer it back to the camera body. The cell should read as valid once it has been recognised by either the charger or the body at a stable voltage above 3.5V.