Xiaoyi AZ13-1 Replacement Battery 3.7V 850mAh Li-ion

Xiaoyi AZ13H / YDXJ01XY — 3.7V Li-ion Replacement Battery (AZ13-1)

This is a 3.7V 850mAh Li-ion cell replacing the original AZ13-1 battery in the Xiaoyi AZ13H and YDXJ01XY action cameras. It fits the same physical footprint at 36.35 × 32.30 × 7.82mm and drops into the same battery compartment. Voltage and watt-hour rating (3.15Wh) match OEM spec.

• AZ13H and YDXJ01XY compatibility: Both models run the same 3.7V single-cell architecture and share the AZ13-1 connector and BMS handshake protocol. One cell fits both without modification.
• Bench tested on actual hardware: We cycled this cell through the AZ13H body and confirmed the BMS accepted the cell on first install, with charge termination and discharge cutoff triggering at expected thresholds.
• First-cycle acceptance on action cameras: Run one full charge through the camera body or OEM charger before heavy recording. Some Xiaoyi BMS firmware maps battery-remaining percentages only after seeing a complete charge curve from the new cell — skipping this step causes erratic indicator readings early on.

Battery percentage jumping on the AZ13H display after fitting a new cell

The AZ13H maps remaining capacity by tracking voltage against a stored discharge curve. A fresh cell has a slightly different resting voltage profile than a used OEM cell, so the indicator can read inaccurately until the camera calibrates. Complete one full charge-to-discharge cycle through the camera body. After that cycle, the firmware anchors its curve to the new cell and the percentage display stabilises.

AZ13H showing dead battery icon on a cell that still has charge

This happens when the camera's low-voltage cutoff triggers before the cell is actually empty — usually because the BMS hasn't completed its first calibration cycle on the new cell. The camera reads the voltage floor as lower than actual capacity. Charge the battery fully in the camera body, then run it down through normal recording until shutdown. One complete cycle resets the cutoff threshold and the false-empty warnings stop.