Sony DCR-PC55S Replacement Battery NP-FA50 7.4V 680mAh

Sony DCR-PC55S / DCR-PC53 Series — 7.4V Li-ion Replacement Battery (NP-FA50)

This is a 7.4V, 680mAh Li-ion replacement for the Sony NP-FA50 battery pack. It fits the DCR-PC55S, DCR-PC55ES, DCR-PC53, DCR-HC90ES, and over a dozen related MiniDV camcorders. The cell matches OEM voltage and capacity — 5.03Wh total energy.

• DCR-PC55 and DCR-HC90 series fit: These models share the NP-FA50 form factor, connector pinout, and BMS communication protocol across the range. The same 7.4V nominal rail and physical housing dimension — 75.50 × 47.00 × 7.00mm — runs through all of them. One cell fits the full group.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on DCR-series hardware. The BMS handshake completed without error flags on both the camera body and an OEM Sony charger. Voltage held steady across the discharge curve until the low-battery cutoff.
• First-install charge cycle on MiniDV bodies: Sony's BMS on these camcorders maps the battery-remaining indicator by learning the cell's discharge curve during its first full charge inside the camera body. Run the first charge through the camera, not a third-party charger, so the indicator reads accurately from the first session.

Sony NP-FA50 BMS rejecting third-party cell on first install

The DCR-PC55S and related bodies use a three-pin connector that carries both power and a data line. On first install, the camera polls the battery for authentication. If the cell arrives partially discharged, the handshake can fail — the body reads no valid response and throws a battery error. Inserting the cell and charging it fully inside the camera body, rather than externally first, gives the BMS the full handshake window it needs. After one complete in-body charge cycle, the error clears on every subsequent insert.

Battery percentage jumping erratically during recording

This happens when the camera's fuel gauge is mapping a new cell's discharge curve against the calibration stored for a worn original cell. The NP-FA50 at 680mAh has a relatively flat mid-range voltage curve — the indicator can jump between segments rather than step down smoothly. One full discharge-to-cutoff followed by a full recharge inside the camera body resets the calibration. After that single recalibration cycle, the percentage display tracks the actual state of charge correctly.