Canon BP-422 DM-MV3 Replacement Battery 7.4V 3000mAh

Canon DM-MV3 Series — 7.4V Li-ion Replacement Battery (BP-422)

The BP-422 is a 7.4V, 3000mAh Li-ion cell for Canon's DM-MV3 family of MiniDV camcorders. It fits the DM-MV3, DM-MV3i, DM-MV3iMC, DM-MV3MC, and more than 22 additional compatible models. Capacity figures are drawn from the product specification, not third-party estimates.

• DM-MV3 family compatibility: Canon's DM-MV3 lineup shares a common BP-400 series connector and voltage rail across body variants. The BMS in each body reads cell voltage and temperature via the same three-pin contact layout, so one battery services the full range without re-configuration.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a DM-MV3 body. The BMS accepted the cell on first install, stabilised at 8.3V peak charge, and held the low-voltage cutoff at 6.0V without tripping into protective shutdown during normal playback and record loads.
• First-use charge cycle on MiniDV bodies: Charge this battery fully inside the Canon OEM charger or the camera body before your first recording session. The DM-MV3's battery indicator calibrates its remaining-charge display during that initial cycle — skipping it causes the indicator to read inaccurately from the first use.

Why the DM-MV3 battery indicator jumps erratically after fitting a new cell

The DM-MV3 maps its battery-level display against a voltage-threshold table tuned to the original cell's discharge curve. A new cell — even one with identical capacity — discharges through those thresholds at a slightly different rate. The body interprets mid-discharge voltage plateaus as sudden capacity changes and the indicator jumps. Running one full charge-discharge cycle inside the camera body lets the BMS re-map its thresholds against the actual discharge curve of the new cell. After that cycle, the display stabilises.

DM-MV3 showing a dead-battery icon immediately after fitting a fully charged replacement

This happens when the BMS has not yet completed an authentication handshake with the new cell. The camera reads an open-circuit voltage it hasn't previously logged and defaults to empty as a fail-safe. Remove the battery, reinsert it firmly until the contact clicks, then power on. If the icon persists, place the battery in the OEM charger until the charge LED cycles to green — the charger handshake initialises the cell at 8.3V and the camera body accepts it on the next install.