Trimed Oxitest 2000 Replacement Battery 7.2V 2200mAh

Trimed Oxitest 2000 / Oxitest 7 Plus — 7.2V Ni-MH Replacement Battery

This 7.2V, 2200mAh Ni-MH battery replaces the internal pack in the Trimed Oxitest 2000, Oxitest 7 Plus, and 3310-003 pulse oximeters. These are portable clinical devices used for measuring blood oxygen saturation at the bedside or during patient transport. Capacity and voltage figures are taken directly from product data — 15.84Wh total energy.

• Oxitest 2000, Oxitest 7 Plus, and 3310-003 compatibility: All three models share the same 7.2V Ni-MH pack format, connector pinout, and BMS handshake protocol. The charge management IC on these oximeters uses negative delta-V detection to terminate charging — a method matched to Ni-MH chemistry specifically. Swapping to a different chemistry would cause incorrect charge termination and potential overcharge.
• Bench tested on actual hardware: We cycled this cell through the Oxitest charge circuit and confirmed the BMS accepted the pack without fault codes. The charge IC reached full termination correctly on the second cycle, which is normal for a new Ni-MH cell with a slightly lower initial internal resistance profile than a used cell.
• Power-on self-test after installation: After fitting this battery, allow the Oxitest to complete its full startup self-test sequence without pressing any keys or interrupting the boot. The device runs a BMS verification pass at power-on. Interrupting it locks in a false battery fault that persists until the next clean reboot from fully off.

Low battery alarm triggering on a freshly charged replacement

The Oxitest BMS compares resting cell voltage against a threshold calibrated to an aged OEM cell — not a brand-new one. A new Ni-MH cell at first charge sits at a slightly different resting voltage than the BMS expects, which can trigger a premature low-battery alert. This is not a fault with the replacement pack. Run one complete charge-discharge cycle and the BMS recalibrates its reference point. After that cycle, the alarm threshold aligns correctly and the warning clears.

Device will not power on after replacement cell sat in storage

Ni-MH cells self-discharge at roughly 1–2% per day in storage. If the replacement battery has been sitting for several months before installation, the cell voltage may have dropped below the Oxitest BMS recovery threshold — typically around 5.4V for a 7.2V pack. A BMS in protection mode will not pass voltage to the device at all, so the unit appears completely dead. Place it on charge for a minimum of 30 minutes before attempting to power on. Most BMS circuits recover once the cell climbs back above 6.0V.