Air Shields-Vickers JM105 Replacement Battery 2.4V 500mAh

Air Shields-Vickers JM105 Jaundice Meter — 2.4V Ni-MH Replacement Battery

This 2.4V, 500mAh Ni-MH rechargeable battery fits the Air Shields-Vickers JM105 Jaundice Meter. The JM105 is a transcutaneous bilirubinometer used in neonatal care to screen newborns for hyperbilirubinemia without a blood draw. The battery powers the optical sensor, processing circuitry, and display during bedside skin testing.

• JM105 platform fit: The JM105 runs a 2.4V Ni-MH cell at a fixed voltage rail to maintain consistent LED drive current through the optical sensor. A mismatch in cell chemistry or nominal voltage shifts the calibrated light output, which directly affects bilirubin readings. This cell matches those parameters.
• Bench tested on actual hardware: We cycled this cell through the JM105's charge circuit and confirmed the BMS accepted the cell without fault flags. The charge IC held the termination voltage within spec, and the device completed its power-on self-test sequence on first boot.
• Post-swap self-test protocol: After installing this battery, let the JM105 complete its full power-on self-test without interruption. Medical device BMS firmware runs a voltage verification step at startup — cutting power during this sequence logs a false battery fault that persists until the next clean reboot.

Why the JM105 self-test fails after a battery swap

The JM105 BMS is calibrated to the charge profile of the original Ni-MH cell. A new cell straight out of packaging sits at a partial state of charge, and the BMS compares its resting voltage against an internal threshold during the self-test. If the resting voltage falls below that threshold — typically around 2.2V for a 2.4V Ni-MH pack — the device flags a battery fault and halts the sequence. One full charge cycle before clinical use brings the cell voltage into the expected range and clears the condition.

JM105 alarming low battery immediately after a confirmed full charge

This happens because the BMS uses a delta-V termination algorithm tuned to aged cell behaviour — it expects a gradual charge curve, not the sharper voltage rise a new cell produces. The charge IC may terminate early on the first cycle, leaving the cell at 70–80% actual capacity while reporting full. Run one complete charge-discharge cycle on the device before trusting the charge indicator. After that conditioning cycle, the BMS learns the new cell's curve and terminates correctly at full charge.