MIR Spirolab Spirometer II Compatible Battery 7.2V 3700mAh

MIR Spirolab Spirometer II/III — 7.2V Ni-MH Replacement Battery (E-0199)

This 7.2V, 3700mAh Ni-MH battery replaces the original power cell in the MIR Spirolab Spirometer II and III series, including the Spirolab III colour variant. It fits devices using OEM part numbers E-0199, MB865A, and MH0057. The Spirolab is a portable spirometer used for pulmonary function testing in clinical settings.

• Spirolab II, III, and III colour compatibility: These Spirolab variants share the same 7.2V battery rail, physical footprint (101.00 × 68.40 × 17.56mm), and connector layout. The BMS handshake protocol is consistent across the series, so one cell fits all three without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on Spirolab hardware. The BMS accepted the cell without fault codes, completed the charge IC handshake, and held voltage within the device's operating range across the full load profile of a standard spirometry test sequence.
• Post-installation self-test protocol: After fitting this battery, allow the Spirolab to complete its full power-on self-test without interruption. The device runs a BMS verification routine at startup — cutting power during this sequence triggers a false battery fault flag that persists until the next clean reboot.

Spirolab not completing boot sequence after battery swap

The Spirolab runs a hardware self-test during every boot cycle, and a new Ni-MH cell that hasn't completed a full charge-discharge cycle can report a voltage that sits just below the BMS's verification threshold. The device interprets this as a fault and stalls the boot sequence rather than proceeding to the test interface. This is not a defective cell — it's a threshold mismatch between a new, unconditioned cell and the BMS's OEM-calibrated acceptance window. Charge the battery to full, run one complete discharge under normal device use, then recharge fully before expecting clean boot behaviour.

Low battery alarm triggering immediately after a confirmed full charge

This happens when the Spirolab's BMS compares the resting voltage of a new Ni-MH cell against a threshold calibrated for a broken-in OEM cell. A fresh Ni-MH cell rests at a slightly lower open-circuit voltage before its first few cycles, and the device reads this as a depleted pack. The fix is one full charge-discharge cycle — after that, the resting voltage climbs into the BMS's accepted range and the alarm clears. Confirm resting voltage is at or above 7.2V after the conditioning cycle before returning the device to clinical use.