Xiaomi Yi AZ13H Replacement Battery 3.7V 850mAh Li-ion

Xiaomi Yi AZ13H / YDXJ01XY / AZ13-1 — 3.7V Li-ion Replacement Battery

This is a 3.7V 850mAh Li-ion cell for the Xiaomi Yi action camera range, covering the AZ13H, YDXJ01XY, and AZ13-1 bodies. It slots directly into the same battery compartment as the original and draws from the same voltage rail. Capacity is 850mAh (3.15Wh), matching the OEM specification.

• AZ13H, YDXJ01XY, and AZ13-1 compatibility: All three models share the same compact battery bay, connector orientation, and 3.7V nominal voltage. One cell works across the entire Xiaomi Yi first-generation action camera platform without modification.
• Bench tested on actual hardware: We cycled this cell through the Xiaomi Yi body at standard 1080p recording load. The BMS accepted the cell without rejection flags and held voltage above 3.5V through the bulk of the discharge curve before cutoff.
• First charge cycle on the Yi body: Charge this cell once inside the camera body before heavy recording. The Xiaomi Yi BMS maps battery-remaining percentage against the cell's discharge curve on the first in-body charge — skipping this step can cause the indicator to read inaccurately from the start.

Why the Xiaomi Yi displays a dead battery icon on a partially charged replacement cell

The Xiaomi Yi uses a voltage-threshold system to estimate remaining charge. A new cell sitting at storage voltage (around 3.6–3.7V) can fall outside the threshold window the camera expects at startup, triggering a low or dead battery warning even though the cell has usable charge. This is a BMS calibration issue, not a faulty cell. Run one full charge cycle through the camera body to let the firmware re-map the thresholds to this cell's actual discharge curve. After that cycle, the indicator will track accurately.

Battery percentage jumping erratically on the Xiaomi Yi display

Erratic percentage readings happen when the camera's voltage-to-percentage lookup table doesn't yet match the new cell's discharge profile. The Yi reads raw voltage at set intervals and converts it to a percentage using a fixed curve — if the cell's curve sits slightly outside that map, the display jumps. This is common on the first partial discharge cycle. Complete one full discharge to cutoff followed by a full charge inside the camera body. After that conditioning cycle, the percentage reading stabilises and tracks within a few points of actual remaining capacity.