Sony NP-FV50A Camcorder Replacement Battery 7.3V 1600mAh

Sony FDR-AX40 / FDR-AX45 Series — 7.3V Li-ion Replacement Battery (NP-FV50A)

This is a 7.3V, 1600mAh Li-ion replacement for the Sony NP-FV50A battery pack. It fits the FDR-AX40, FDR-AX45, FDR-AX60, HDR-CX625, and nine additional Sony camcorder models. Slot it in exactly where the original sits — same connector, same form factor.

• FDR-AX and HDR-CX platform fit: These Sony camcorder lines share a common NP-FV series battery bay, the same 7.3V rail, and an identical multi-pin InfoLITHIUM connector. That connector carries bidirectional data between cell and body — the BMS reads charge state and cell ID through the same pins that deliver power.
• Bench tested on actual hardware: We ran this cell through the FDR-AX40 body, cycling charge and discharge while monitoring the InfoLITHIUM communication handshake. The BMS accepted the cell on first install and reported charge level without triggering the incompatible-battery warning.
• First charge cycle on the FDR-AX40: Perform the initial full charge inside the camera body rather than a standalone charger. The FDR-AX40's InfoLITHIUM system calibrates its battery-remaining display during that first in-body charge cycle — skipping this step can cause the indicator to read inaccurately for the first several uses.

Sony InfoLITHIUM handshake rejection on third-party cells

Sony's InfoLITHIUM system does more than deliver power — it exchanges digital data on cell temperature, charge history, and identity through the multi-pin connector. A replacement cell that doesn't mirror the expected data packet triggers a "cannot use this battery pack" warning on screen. This happens most often when the cell is inserted into a cold body or after the camera firmware was recently updated. The fix is to charge the replacement cell fully inside the camera body first, which re-initialises the handshake sequence. After one complete in-body charge cycle, the warning clears and the battery-remaining indicator tracks normally.

Battery percentage jumping erratically on the FDR-AX40 display

The FDR-AX40's fuel gauge maps voltage thresholds to percentage steps calibrated around Sony's original NP-FV50A discharge curve. A new replacement cell — even a correctly spec'd one — can read differently at each voltage step until the camera logs a few complete cycles. You'll see the indicator drop from 80% to 55% in seconds, then stall for a long stretch. Run two or three full charge-to-discharge cycles through the camera body. By the third cycle, the voltage-to-percentage mapping stabilises. If it hasn't settled after three cycles, check that the multi-pin connector is seated flush — even a 0.5mm gap interrupts the data line and causes erratic readings.