JVC BN-V312U Replacement Battery 7.4V 1260mAh Li-ion

JVC GR-DVX707EG Series — 7.4V Li-ion Replacement Battery (BN-V312U)

This is a 7.4V, 1260mAh Li-ion cell that replaces the BN-V312U, BN-V312, BN-V306, and BN-V306U batteries in JVC compact video cameras. It fits the GR-DVX707EG, GR-DVX509, GR-DVX407EG, GR-DVX400, and 16 additional GR-series models. Voltage and capacity match OEM spec exactly.

• GR-DVX and GR-D series fit: These JVC camcorders share the same battery bay geometry, 7.4V voltage rail, and BN-V3xx connector footprint. One cell covers the full range listed in the compatibility data.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a GR-series body. The BMS accepted the cell without fault flags, and the charge indicator tracked normally through the full cycle.
• First charge cycle on a JVC body: Charge the new cell fully inside the JVC camera body or OEM charger before first use. Some JVC BMS firmware needs an in-body charge cycle to calibrate the battery-remaining display to the new cell's discharge curve.

Battery percentage jumping or freezing on the GR-DVX display

JVC's GR-series battery gauge maps voltage thresholds from the original BN-V312U discharge curve. A new Li-ion cell has a slightly steeper initial voltage drop before settling into its flat mid-range plateau. The camera's indicator reads that early drop as a larger capacity loss than it actually is, causing the percentage to jump or stall. One full charge-discharge cycle inside the camera body lets the BMS re-map its thresholds to the new cell. After that cycle, the display tracks accurately.

GR-DVX707EG showing dead battery icon immediately after inserting a new cell

This happens when the cell arrives at a storage charge — typically around 3.8V total — and the camera's BMS threshold sits just above that voltage at startup. The camera reads the resting voltage as critically low rather than partially charged. Insert the battery and connect to the OEM charger immediately, even for 10 minutes, before powering on. Once the cell climbs above the BMS low-voltage lockout threshold, the icon clears and the camera boots normally.