About this replacement
Sony CyberShot DSC-S750 / DSC-S980 Series — 3.7V Li-ion Replacement Battery (NP-BK1)
This is a 3.7V, 770mAh (2.85Wh) Li-ion replacement battery for the Sony CyberShot compact camera range. It fits the DSC-S750, DSC-S780, DSC-S950, DSC-S980, and 38 additional models sharing the NP-BK1 and NP-FK1 specification. The cell matches Sony's original voltage rail and connector pinout for this series.
- NP-BK1 / NP-FK1 platform compatibility: These models share the same battery bay geometry, 3.7V nominal voltage rail, and BMS communication protocol. A single cell design covers the full S-series compact lineup without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on DSC-S series bodies. The BMS accepted the cell without error flags after one full charge cycle completed inside the camera body.
- First-use charge cycle: Insert the battery and charge it fully inside the camera body or the OEM Sony charger before shooting. Some S-series bodies need a complete in-body charge cycle to calibrate the battery-remaining indicator against the new cell's discharge curve.
Flash recycling slowing down mid-shoot on the DSC-S750
The DSC-S750's onboard flash capacitor draws a sharp recharge current burst after each shot. As a Li-ion cell ages or sits at a lower state of charge, internal resistance rises and that recharge current sags. The camera body interprets slow capacitor refill as low power and may lock the shutter until recycling completes. If flash lag is increasing, check cell voltage under load — anything below 3.5V at rest indicates the cell needs replacement.
Battery percentage jumping or dropping suddenly on the display
The S-series battery indicator maps voltage thresholds to percentage steps, not a true fuel-gauge IC. A new cell has a slightly different discharge curve than the original Sony cell, so the indicator can skip steps or drop several bars at once. This is a calibration mismatch, not a faulty battery. Run two full charge-to-discharge cycles inside the camera body and the indicator will stabilise against the new cell's actual curve.