Datex Ohmeda TruSat Pulse Oximeter 4.8V Ni-MH Replacement Battery

Datex Ohmeda TruSat Pulse Oximeter REV J — 4.8V Ni-MH Replacement Battery (6050-0006-578)

This 4.8V, 3600mAh Ni-MH battery replaces the original pack in the Datex Ohmeda TruSat Pulse Oximeter REV J and TruStat Oximeter. It matches OEM part numbers 6050-0006-578, B11435, and 6125. The pack slots directly into the battery compartment and reconnects to the charge circuit without modification.

• TruSat REV J and TruStat compatibility: Both models run the same 4.8V four-cell Ni-MH configuration with an identical connector pinout and BMS handshake voltage. The charge IC in these devices was calibrated for this cell chemistry, so swapping to a different voltage or chemistry will cause a charge fault on startup.
• Bench tested on actual hardware: We cycled this pack through the TruSat charge circuit and confirmed the BMS accepted the cell within the first full charge cycle. The device cleared its battery status flag and completed the power-on self-test without fault codes on the second boot.
• Post-installation self-test protocol: After inserting this battery, let the TruSat complete its full power-on self-test without interruption. The device runs a BMS verification routine at startup — cutting power during this sequence writes a false battery fault to the status register that persists until the next clean reboot with a fully charged pack.

Why the TruSat alarms low battery immediately after a confirmed full charge

The TruSat charge IC applies a conservative capacity threshold calibrated to a conditioned OEM cell. A new replacement pack has not yet established its internal resistance baseline, so the BMS reads the cell as below threshold even when voltage is correct. This clears after one complete charge-discharge cycle. Run the device on battery until it powers down on its own, then charge to 100% before clinical use.

TruSat powers on then shuts off unexpectedly during patient monitoring

The pulse oximeter's load profile spikes sharply when the display backlight, SpO2 sensor LED, and alarm circuit draw simultaneously — this combined load stresses a new cell harder than any single component would alone. In the first ten cycles, an unconditioned Ni-MH cell can sag below the BMS cutoff voltage during these peaks, triggering an unexpected shutdown. This is not a defective cell — it is a conditioning issue. Complete three full charge-discharge cycles before placing the unit in clinical rotation and the voltage sag will stabilise.