About this replacement
Sony HDR-TG1 / DSC-HX1 Series — 7.4V Li-ion Replacement Battery (NP-FV100)
This is a 7.4V, 1950mAh lithium-ion replacement for the Sony NP-FV100 battery pack. It fits the HDR-TG1, HDR-TG3E, HDR-TG5, DSC-HX1, and 48 additional Sony camcorder and camera models sharing the same battery bay and connector pinout. Capacity is 1950mAh (14.43Wh), matching the original specification.
- Multi-model fit across the HDR-TG and DSC-HX platforms: Sony's HDR-TG and DSC-HX lines share the NP-FV100 form factor, voltage rail, and five-pin communication interface. The BMS in these camera bodies reads cell state-of-charge and temperature data through that interface — the connector and protocol are identical across the listed models.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on an HDR-TG5 body. The BMS handshake completed on first cycle, the battery percentage indicator tracked consistently, and the over-discharge cutoff triggered correctly at the expected low-voltage threshold.
- First-cycle charge protocol for accurate display: On the HDR-TG1 and DSC-HX1, perform the initial charge inside the camera body or with the OEM BC-TRP charger — not a generic multi-chemistry charger. Sony's BMS maps remaining-charge display to its own charge profile; a full cycle from within the native charger lets the body calibrate the percentage indicator to the new cell's discharge curve.
Why the HDR-TG1 displays a dead-battery indicator on a partially charged replacement cell
Sony's fuel-gauge circuit in the HDR-TG series maps the battery percentage to a learned discharge curve stored from previous charge cycles. A new cell with no history reads as unknown, and the body sometimes defaults to a low or empty indicator even when the cell is at 50–70% state of charge. This is not a faulty battery — it is the BMS working with no baseline. Running one full charge cycle inside the camera body or OEM charger resets the learned curve and aligns the display to the actual cell voltage, typically 8.2–8.4V at full charge.
Battery percentage jumping erratically during recording on the HDR-TG5
The HDR-TG5 draws variable current during video — sensor readout, optical image stabilisation, and the LCD backlight all spike load simultaneously during panning or low-light shooting. A replacement cell with a slightly different internal resistance than the original will show voltage sag under those spikes, which the BMS reads as a sudden capacity drop. The percentage indicator then jumps down, recovers when load eases, and repeats. Completing two full charge-discharge cycles normalises the BMS's resistance model for the new cell, and the display stabilises.