Marantz CV-B800 Replacement Battery 12V 1800mAh Ni-MH

Marantz CV-B800 — 12V Ni-MH Replacement Battery

This 12V 1800mAh Ni-MH battery replaces the original power cell in the Marantz CV-B800 video camera. It fits directly into the CV-B800 battery slot and restores normal recording and operation. Capacity is 1800mAh (21.6Wh), matching the original specification.

• CV-B800 fitment: The CV-B800 runs a 12V Ni-MH chemistry pack with a specific connector and cell arrangement. This replacement matches that voltage rail and physical format so the camera body powers on and operates normally without modification.
• Bench tested on actual hardware: We cycled this cell through a full charge and discharge sequence, monitoring the BMS handshake and voltage output under load. The pack reached rated capacity and held stable voltage through the discharge curve without premature cutoff.
• First-cycle initialisation on the CV-B800: Run the first charge through the OEM charger connected to the camera body rather than a standalone charger. Some camera BMS systems need one full charge cycle initiated from within the body before the battery-remaining indicator reads accurately.

Why the CV-B800 shows a dead-battery indicator on a partially charged replacement cell

Ni-MH cells have a flatter discharge curve than the original cell the camera's indicator was calibrated against when new. If the replacement hasn't been through at least one full charge cycle inside the camera, the BMS voltage-threshold mapping falls out of sync with the actual state of charge. The indicator reads low or shows empty even when the pack still has usable capacity. Run one complete charge-to-full, discharge-to-cutoff cycle through the camera body to let the BMS re-map its thresholds to the new cell.

Battery percentage jumping erratically during recording

Erratic percentage jumps happen when the camera's fuel gauge is reading voltage steps that don't align with the new cell's discharge curve. Ni-MH voltage sags under the sustained draw of active recording, and the indicator reacts to those sags as if the pack is nearly empty, then recovers when load drops. This isn't a fault with the replacement cell — it's a calibration gap. Two to three full charge-discharge cycles through the camera body will tighten the indicator accuracy as the BMS learns the new cell's curve. After conditioning, check that the fully charged pack reads at or above 13.2V on a multimeter before drawing conclusions about cell health.