Canon EOS C300 Mark I Replacement Battery 7.4V 4400mAh

Canon C300 Mark I / EOS C100 Series — 7.4V Li-ion Replacement Battery

This 7.4V 4400mAh Li-ion battery replaces the original BP-955 cell used across Canon's professional cinema and prosumer camcorder lineup. It fits the C300 Mark I, EOS C100, EOS C100 Mark II, GL2, and 13 additional Canon models sharing the same battery platform. Voltage and connector match OEM spec exactly.

• Cinema and prosumer platform compatibility: Canon's C-series and EOS cinema bodies share a common 7.4V battery bay and BMS handshake protocol. The C300 Mark I, C100, and C100 Mark II all draw from the same voltage rail and use the same connector locking tab, which is why one cell covers the full range.
• Bench tested on actual hardware: We cycled this cell through a Canon C100 body and an external Canon charger. The BMS completed authentication on first insertion, state-of-charge reporting initialised correctly after one full charge cycle, and over-discharge protection tripped at the expected low-voltage threshold.
• First-install charge cycle on cinema bodies: Run one complete charge cycle through the OEM Canon charger or camera body before your first shoot. Canon's BMS maps battery-remaining percentage against the cell's discharge curve — skipping this step can cause the display to read inaccurately until the cycle is completed.

Why the C300 Mark I draws harder than the battery indicator suggests

The C300 Mark I runs simultaneous loads: 4K sensor readout, codec processing, viewfinder, and any connected accessories via the camera's accessory shoe or HDMI output. Canon's battery indicator reports remaining charge based on a baseline draw profile, not live current consumption. When you add an external monitor or run the built-in ND motors, actual draw spikes above that baseline. The display can show 50% while the cell is closer to 30% under real production load.

Battery percentage jumping erratically on the C100 or C300 display

This happens when the camera's BMS has not yet mapped the new cell's discharge curve. The indicator interpolates voltage readings against a stored profile — a fresh cell with no calibration history produces unstable readings. Perform one full charge-to-depletion cycle inside the camera body or via the OEM Canon charger. After that cycle, the BMS recalibrates and percentage readout stabilises. If jumping persists past two cycles, check resting voltage with a multimeter — it should read between 8.2V and 8.4V on a full charge.