Eagle Eye Extreme HD Replacement Battery 3.7V 1100mAh Li-ion

Eagle Eye Extreme HD — 3.7V Li-ion Replacement Battery

This 3.7V, 1100mAh lithium-ion cell is a direct replacement for the Eagle Eye Extreme HD compact camera. It slots into the same battery compartment as the original and powers the camera's image capture, video recording, and onboard processing. Voltage and capacity match the OEM specification exactly.

• Extreme HD platform fit: The Extreme HD runs a 3.7V single-cell architecture with a BMS tuned to li-ion discharge curves. This cell matches that voltage rail and cell profile, so the camera's charge controller reads it correctly from the first cycle.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a camera-class BMS test rig. The protection circuit responded correctly to overcharge cutoff and low-voltage trip points, and the cell held capacity within spec across multiple cycles.
• First-cycle charge protocol for the Extreme HD: Run the first full charge from inside the camera body using the OEM charging cable — not a standalone universal charger. Some compact camera BMS systems only calibrate the battery-remaining indicator after completing one charge cycle through the camera body itself.

Camera showing dead battery indicator on a partially charged replacement cell

The Extreme HD maps its battery-level display to a voltage-threshold table calibrated during the first charge cycle. A new cell that hasn't completed that cycle will report inaccurate state-of-charge, often showing near-empty even when the cell is at 3.9V or above. This is a BMS calibration issue, not a fault with the cell. Charge the battery fully inside the camera body once, and the indicator will track correctly from that point forward.

Battery percentage jumping erratically mid-shoot

Erratic percentage readings happen when the camera's voltage-threshold map doesn't match the discharge curve of the new cell. The Extreme HD samples terminal voltage at intervals and converts that to a percentage — if the curve shape differs slightly from the OEM cell, readings can jump 10–20% between frames. This is most visible between 50% and 20% displayed charge. One full discharge-to-cutoff cycle followed by a full charge inside the camera body resets the calibration to the new cell's curve.