HoytTech HD1 Replacement Battery 3.7V 1100mAh Li-ion

HoytTech HD1 — 3.7V Li-ion Replacement Battery

This 3.7V 1100mAh Li-ion cell replaces the original battery in the HoytTech HD1 compact digital camera. It fits the HD1 body directly and supports both photo and video capture modes. Capacity is 1100mAh (4.07Wh), matching the original cell specification.

• HD1 platform fit: The HD1 uses a slim Li-ion cell with a single-cell 3.7V nominal rail. This replacement matches that voltage rail and physical footprint — 53.10 x 38.40 x 8.00mm — so the door closes and the contacts seat correctly without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench, monitoring BMS handshake behaviour. The protection circuit responded correctly to end-of-charge and low-voltage cutoff events without false tripping.
• First-use charge cycle in the HD1 body: Run the first full charge through the camera body itself, not an aftermarket external charger. Some compact camera BMS systems only begin accurate battery-remaining calibration after completing one charge cycle from within the body — skipping this step can cause the indicator to read erratically from the start.

HD1 battery indicator jumping between levels mid-shoot

The HD1 maps its battery percentage display to a voltage-threshold table built around the original cell's discharge curve. A new replacement cell may have a slightly different curve, especially in the mid-range between 3.9V and 3.6V. The indicator can jump — say, from 60% to 30% — not because power is draining fast, but because the camera hits a voltage threshold sooner than its table expects. After two or three full charge-discharge cycles, the readings typically stabilise as the cell's curve settles.

HD1 showing dead battery indicator on a partially charged replacement

If the HD1 displays a dead or absent battery icon immediately after inserting a new cell, the camera's BMS has not yet accepted the replacement. This happens when the cell voltage sits below the camera's recognition threshold — typically under 3.0V — after storage. Place the battery in the HD1, connect the camera to its OEM charger, and allow it to charge from within the body. Once the charger pushes the cell above 3.2V, the camera should recognise it and the icon will clear.