EKO HD 720p Compatible Battery 3.7V 900mAh Li-ion

EKO HD 720p / Full HD 1080p / Ultra HD 4K Wifi — 3.7V Li-ion Replacement Battery

This 3.7V 900mAh (3.33Wh) lithium-ion cell replaces the original battery in the EKO HD 720p, Full HD 1080p Wifi, and Ultra HD 4K Wifi action cameras. All three models share the same compact cell footprint and voltage rail, so one replacement covers the range. Capacity figure is taken directly from the product specification — 900mAh at 3.7V nominal.

• EKO action camera series fit: The HD 720p, Full HD 1080p Wifi, and Ultra HD 4K Wifi all draw from the same 3.7V cell architecture with a shared connector and matching BMS communication protocol, which is why a single replacement cell covers all three variants without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the action camera platform, confirmed the BMS handshake completed without fault flags, and verified the camera body accepted the cell and reported charge status correctly through the indicator.
• First-cycle initialisation on EKO action cameras: Run the first full charge cycle through the camera body itself, not a third-party external charger — the EKO BMS maps the discharge curve during this first cycle to calibrate the battery-remaining indicator accurately for subsequent sessions.

Why the EKO camera shows a dead battery icon on a freshly charged replacement cell

The EKO action camera reads battery state by mapping voltage against a stored discharge curve from the original cell. A new replacement cell has a slightly different resting voltage profile, so the camera's indicator can misread it as depleted even when fully charged. This is a calibration mismatch in the BMS, not a cell fault. One full charge and discharge cycle through the camera body resets the mapping and the indicator will read accurately from that point forward.

Battery percentage jumping erratically during recording

This happens when the camera's voltage-threshold table doesn't yet align with the new cell's discharge curve — the indicator jumps because voltage readings land between the stored reference points. It's most visible during sustained 4K recording, where current draw is higher and voltage sag is more pronounced. The fix is the same first-cycle calibration: charge fully via the camera body, run the cell down to auto-shutoff, then recharge. After one complete cycle the percentage reading stabilises and tracks correctly.