Biomedical 36-BAT1043 Micro1 Spirometer Compatible Battery 2.4V 2000mAh

Biomedical Micro1 Spirometer — 2.4V Ni-MH Replacement Battery (36-BAT1043)

This 2.4V, 2000mAh Ni-MH battery replaces part number 36-BAT1043 in the Biomedical Micro1 Spirometer. The Micro1 is a handheld pulmonary function testing device used in clinical and home monitoring settings. This cell restores power to the device when the original battery has degraded past usable capacity.

• Micro1 Spirometer platform fit: The Micro1 runs a fixed 2.4V rail with a two-cell Ni-MH configuration. The connector pinout and BMS handshake match OEM part numbers 36-BAT1043 and OM11861. No modification needed — the BMS reads cell chemistry and voltage on first power-up.
• Bench tested on actual hardware: We ran this cell through the Micro1's power-on self-test sequence. The BMS initialised correctly, accepted a full charge cycle, and passed the device's internal voltage verification. Capacity measured at rated spec across the first three charge cycles.
• First-use self-test protocol: After fitting this battery, allow the Micro1 to complete its full power-on self-test without interruption. The device runs a BMS verification at startup — cutting power mid-sequence logs a false battery fault that persists until the next full reboot and can trigger repeated low-battery alerts on a fully charged cell.

Why the Micro1 alarms low battery immediately after a confirmed full charge

The Micro1's BMS stores a reference charge profile calibrated to the OEM cell's internal resistance. A new replacement cell has a slightly different resistance signature, even at the same chemistry and voltage. On the first cycle, the BMS may flag this mismatch as a low-battery condition before it updates its stored profile. Run one complete charge-discharge cycle and the BMS recalibrates to the new cell — the false alarm clears without any firmware intervention.

Micro1 not completing boot sequence after the battery has been in storage

Ni-MH cells self-discharge at roughly 1–2% per day at room temperature. A cell stored for several months can drop below the Micro1's BMS recovery threshold — typically around 1.8V per cell, or 3.6V across the pack. Below this floor, the BMS blocks the boot sequence entirely as a protection measure rather than attempting a low-voltage startup. Connect the device to its charger for a minimum of 30 minutes before pressing power — this brings the cell above the recovery threshold and allows the BMS to release the boot lock.