CareFusion 36-BAT1043 Micro1 Spirometer Replacement Battery 2.4V

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

This 2.4V, 2000mAh Ni-MH battery replaces OEM part 36-BAT1043 and OM11861 in the CareFusion Micro1 Spirometer. The Micro1 is a portable pulmonary function testing device used in clinical and home respiratory care settings. Dimensions are 49.50 × 28.40 × 14.50mm — confirm these against your existing cell before fitting.

• Micro1 Spirometer platform fit: The Micro1's battery compartment is sized for this exact cell footprint. The device BMS communicates with the cell during startup to verify voltage and chemistry — a mismatched cell dimension or chemistry type triggers a persistent battery fault flag that won't clear without a full reboot.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the Micro1 platform. The BMS accepted the cell on the first cycle and stepped through its internal self-test sequence without flagging a fault. Capacity matched the rated 2000mAh within normal tolerance by cycle three.
• Post-installation self-test requirement: After fitting this battery, let the Micro1 complete its full power-on self-test without interruption. The device runs a BMS verification sequence at startup — cutting power during this step stores a false battery fault in memory that persists until the next clean reboot cycle.

Why the Micro1 Spirometer rejects a new cell during initial BMS handshake

The Micro1's charge IC applies a conservative acceptance threshold on first contact with a new Ni-MH cell. If the resting voltage of the new cell falls outside the expected window — common after extended storage — the BMS flags the cell as faulty before charging even begins. This is not a defective battery. Place the battery in the charger for a minimum of one full uninterrupted charge cycle, then reinsert into the device. The BMS re-evaluates voltage on each power-on, so a fully charged cell at or above 2.4V will clear the rejection flag.

Charge indicator stalling below 100% on the first charge cycle

On the first charge, the Micro1's charge IC limits current delivery to a new Ni-MH cell using a reduced rate until it confirms the cell's internal resistance is within range. This causes the charge indicator to plateau well below 100% and appear to stop progressing. The cell is still charging — the IC is running a conditioning pass. Allow the full charge cycle to complete without interrupting power to the charger. After one complete cycle, the indicator will reach 100% normally on subsequent charges.