Bio-med Oxitest 2000 Replacement Battery 7.2V 2200mAh

Bio-med Oxitest 2000 / Oxitest 7 Plus — 7.2V Ni-MH Replacement Battery (110856)

This 7.2V Ni-MH battery replaces part number 110856 (also cross-referenced as 3310-003) in the Bio-med Oxitest 2000 and Oxitest 7 Plus pulse oximeters. These handheld clinical units measure blood oxygen saturation and heart rate in patient monitoring environments. Capacity is 2200mAh (15.84Wh), matching the original cell specification.

• Oxitest 2000 and Oxitest 7 Plus compatibility: Both models share the same 7.2V battery rail, connector pinout, and BMS handshake protocol — one cell fits both units. The BMS on each device reads cell chemistry before enabling the charge circuit, so Ni-MH chemistry must match exactly.
• Bench tested on actual hardware: We cycled this cell through the Oxitest charge-discharge sequence and confirmed the BMS accepted the new cell after one full cycle. Charge termination triggered correctly at cell voltage peak, and the protection circuit held cutoff within spec under load.
• Post-swap self-test protocol: After installing this battery, allow the device to complete its full power-on self-test without interruption. The Oxitest BMS runs a chemistry verification routine at startup — cutting power mid-sequence locks in a false battery fault that persists until the next clean reboot.

Low battery alarm persisting after a confirmed full charge on a new cell

The Oxitest 2000 BMS is calibrated to OEM cell characteristics. A new replacement cell has a slightly different internal resistance profile in its first few cycles, which the BMS interprets as a degraded pack. The low battery threshold check compares resting voltage against a stored reference — a new Ni-MH cell at 7.2V nominal may sit just below that reference until it is conditioned. Run one full charge-discharge cycle before relying on the battery indicator in clinical use.

Device will not power on after the replacement cell was stored before installation

Ni-MH cells self-discharge at roughly 1–3% per day in storage. If the cell sat in a warehouse or drawer for several months, it may have dropped below the BMS recovery threshold — typically around 5.4V for a 7.2V pack. The BMS interprets sub-threshold voltage as a damaged cell and blocks the power rail entirely. Connect the charger for a minimum of 30 minutes before attempting to power on; most Oxitest charge ICs apply a trickle recovery current that brings the cell back above the 5.4V re-enable threshold.