About this replacement
JVC GR-DVX34K / GR-DVX6K Series — 7.4V Li-ion Replacement Battery (BN-V306)
This is a 7.4V, 630mAh Li-ion replacement for the JVC BN-V306 battery. It fits the GR-DVX34K, GR-DVX6K, GR-DVX507EG, GR-DVX407, and 16 additional JVC mini-DV camcorder models. Same voltage, same footprint, same connector as the original cell.
- DVX series compatibility: All listed GR-DVX models share the BN-V306 voltage rail and battery bay dimensions. The connector orientation and BMS handshake protocol are consistent across the range, so one cell covers the full group.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a GR-DVX body. The BMS accepted the cell, reported state-of-charge correctly, and held voltage steady through recording load without triggering a premature cutoff.
- First-install charge cycle: Insert the new cell and charge it fully inside the camera body or OEM charger before shooting. Some JVC BMS firmware requires one complete in-camera charge cycle to map the cell's discharge curve and display the battery-remaining indicator accurately.
Why the GR-DVX shows a dead battery icon on a partially charged replacement cell
JVC's BMS uses a voltage-threshold map calibrated to the original cell's discharge curve. A new third-party cell can sit slightly above or below those thresholds at rest, causing the camera to misread state-of-charge on first use. This shows up as a full-battery icon that drops to empty within a few minutes, or a dead-battery warning at what is actually 50% charge. Running one full charge-discharge cycle inside the camera body re-maps the thresholds to the new cell. After that cycle, the indicator tracks accurately through normal use.
Camera body rejecting the BN-V306 replacement on first install
Some GR-DVX bodies flash a no-battery warning or power off immediately when a new third-party cell is inserted cold. This is a BMS authentication check — the camera is reading the cell's resting voltage and comparing it against an expected range. If the cell shipped at a storage charge below 3.5V per cell (7.0V combined), the body may refuse it. Connect the battery to the OEM charger first, bring it to full charge, then insert it into the camera. That single charge cycle is usually enough for the body to accept and communicate with the cell normally.