RealWear HMT-1 Replacement Battery 3.7V 2600mAh B1200G

RealWear HMT-1 / CommWear HMT-1 — 3.7V Li-ion Replacement Battery (B1200G)

This is a 3.7V, 2600mAh (9.62Wh) Li-ion replacement battery for the RealWear HMT-1 and CommWear HMT-1 industrial AR headsets. It uses OEM part number B1200G and fits directly into the battery bay on both variants. Capacity listed is from the product specification — confirmed against the original cell rating.

• HMT-1 and CommWear HMT-1 platform fit: Both headsets run the same voltage rail and use the same B1200G battery form factor. The BMS handshake, connector pinout, and physical housing are identical across both variants, so one battery services either unit.
• Bench tested on actual hardware: We ran this cell through charge-discharge cycles on the HMT-1 platform. The BMS communicated correctly with the headset firmware — charge indicators, low-battery warnings, and cutoff thresholds all triggered at expected voltage levels.
• Voltage floor for AR tracking stability: The HMT-1's tracking processor draws steady current alongside the display and wireless stack. When the cell drops below its minimum stable voltage, the processor loses the clean power it needs before the headset shows a low-battery alert. Swap the battery before the indicator hits 15% during active field use to avoid mid-session dropouts.

Why the HMT-1 loses head-tracking accuracy when battery charge drops

The HMT-1 runs IMU sensors, a camera array, and a display processor simultaneously. Each subsystem needs a stable voltage supply — the tracking stack in particular is sensitive to sag events. When a degraded or low cell can no longer hold voltage under that combined draw, the tracking processor receives noisy or insufficient power before the device formally registers a low-battery state. The result is drift, lag, or sudden positional jumps in the AR overlay — not a software fault. Replacing the battery resolves it if the issue tracks with charge level.

HMT-1 shutting down without a low-battery warning

An aged cell can hold a reported voltage above the warning threshold but collapse under load the moment the display, processor, and wireless radio all draw simultaneously. The headset firmware reads resting cell voltage, not loaded voltage, so it never triggers the warning before the shutdown occurs. This is a voltage-cliff failure — the cell looks charged at rest but cannot sustain the current spike. Check cell health by watching the voltage reading during a high-activity task; a cell dropping below 3.4V under load on a supposedly half-charged unit needs replacement.