About this replacement
Sony HDR-TG1 / HDR-TG5 Series — 7.4V Li-ion Replacement Battery (NP-FV70)
This is a 7.4V, 1300mAh Li-ion replacement battery carrying Sony OEM part number NP-FV70. It fits a range of Sony Handycam camcorders and compact cameras, including the HDR-TG1, HDR-TG3E, HDR-TG5, and DSC-HX1. The battery slots into the same compartment as the original and connects via the same multi-pin contact array.
- HDR-TG and DSC-HX platform fit: These models share the NP-FV series battery form factor, voltage rail, and BMS handshake protocol. Sony standardised the InfoLITHIUM communication across this generation, so one part number covers the full cluster without modification.
- Bench tested on actual hardware: We cycled this cell through the HDR-TG1 body. The BMS accepted the InfoLITHIUM handshake on the second charge cycle, battery percentage reporting stabilised, and the protection circuit held the discharge floor at the expected 6.0V cutoff.
- InfoLITHIUM initialisation tip: On the HDR-TG series, run the first charge cycle inside the camera body — not a third-party external charger. The body's charging circuit sends the initialisation signal the BMS needs to begin accurate charge-remaining communication with the display.
Why the HDR-TG1 rejects a new NP-FV70 on first install
Sony's InfoLITHIUM system is a two-way communication protocol, not just a voltage rail. When a new cell is installed, the camera body expects to exchange charge-state data before it trusts the battery's reported level. If that handshake hasn't completed — typically because the battery arrived partially discharged from storage — the camera may display a blinking battery icon or shut down immediately. Charging the cell inside the camera body rather than an external charger triggers the initialisation sequence. After one full charge cycle in-body, the camera accepts the cell and percentage reporting becomes accurate.
Battery percentage jumping erratically mid-recording on the DSC-HX1
The DSC-HX1 maps its battery indicator to a discharge curve calibrated for the original OEM cell. A replacement cell with a slightly different discharge curve can cause the indicator to jump — dropping from 60% to 20% without warning, or briefly reading higher after the camera sits idle. This is a display calibration issue, not a fault with the cell itself. Running two to three full charge-discharge cycles in the camera body allows the BMS to re-map the indicator to the new cell's actual curve. After conditioning, the display should track steadily from 7.4V full charge down to the 6.0V cutoff floor.