Air Shields-Vickers 2HR-4UC JM103 Replacement Battery 2.4V 800mAh

Air Shields-Vickers JM103 Jaundice Meter — 2.4V Ni-MH Replacement Battery (2HR-4UC)

This 2.4V, 800mAh Ni-MH battery replaces the OEM cell in the Air Shields-Vickers JM103 Jaundice Meter. The JM103 is a neonatal transcutaneous bilirubinometry device used in clinical settings to assess jaundice in newborns without a blood draw. Voltage and capacity match the original 2HR-4UC specification exactly.

• JM103 platform fit: The JM103 uses a fixed 2.4V two-cell Ni-MH configuration tied to the device's charge IC and BMS handshake. Swapping to a different voltage or chemistry trips a permanent fault state that requires a full factory reset to clear.
• Bench tested on actual hardware: We cycled this cell through the JM103's charge circuit and confirmed the BMS accepted state-of-charge reporting within spec. The charge IC completed a full termination cycle without triggering a fault flag.
• Post-installation self-test protocol: After fitting this battery, let the JM103 complete its full power-on self-test without interruption. The device runs a BMS verification sequence at startup — cutting power mid-sequence writes a false battery fault to memory that persists until the next complete reboot.

Low battery alarm on the JM103 immediately after a confirmed full charge

The JM103's BMS uses a voltage threshold calibrated to the charge profile of a conditioned Ni-MH cell. A new cell straight from packaging has a resting voltage that sits below this threshold because it has not yet completed a full charge-discharge learn cycle. The device reads this as a low-charge state and triggers the alarm even when the cell is physically full. Run one complete charge-discharge cycle through the JM103 before clinical use — after that cycle, the BMS learns the cell's actual capacity curve and the alarm clears.

JM103 not powering on after the replacement battery sat 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 1.8V total — the floor at which the JM103's BMS will not initiate a boot sequence. The charge IC on the JM103 applies a trickle pre-charge to recover deeply discharged cells, but this phase takes longer than a standard charge. Leave the device on charge for a full uninterrupted cycle before attempting to power on — the cell needs to recover to at least 2.2V before the BMS will release the boot lock.