Healthdyne 5492 Pulse Oximeter Compatible Battery 6V 4000mAh

Healthdyne 930 Pulse Oximeter — 6V Ni-MH Replacement Battery (5492)

This is a 6V, 4000mAh Ni-MH replacement battery for the Healthdyne 930 Pulse Oximeter and the Smart Monitor 900S, 930S, and 950S series. It replaces OEM part number 5492 and fits the same battery bay without modification. Capacity figures are taken directly from product data — 24Wh total energy.

• 930 and Smart Monitor series compatibility: The 900S, 930S, and 950S share the same 6V battery rail, connector pinout, and BMS handshake protocol as the 930 Pulse Oximeter — one cell type covers the full platform.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the 930 platform. The BMS accepted the new cell without rejection flags, and the charge IC stepped through its conditioning stages as expected on first insertion.
• Post-swap self-test requirement: After installing this battery, allow the device to complete its full power-on self-test without interruption. The 930 runs a BMS verification routine at startup — cutting power during this sequence triggers a false battery fault that persists until the next clean reboot.

Device not completing boot sequence on new battery

The 930 Pulse Oximeter runs a startup BMS verification that checks cell voltage against a minimum acceptance threshold. A new Ni-MH cell sitting in storage can lose enough charge to fall below that threshold before it ever reaches the patient. The device reads this as an unacceptable power source and stalls mid-boot rather than risk a monitoring session on insufficient power. Charge the replacement cell to full before first insertion — the onboard charger will complete a conditioning cycle, and the BMS will pass verification on the next power-on attempt.

Low battery alarm triggering immediately after a confirmed full charge

This happens because the device BMS was calibrated against the discharge curve of the original OEM cell chemistry. A new replacement cell has not yet settled into its characteristic curve — capacity reporting reads low until the cell completes one full charge-discharge conditioning cycle. The alarm threshold the 930 uses is voltage-based, not time-based, and a fresh cell can show a temporarily depressed open-circuit voltage under load. Run one complete charge-to-discharge cycle before clinical use and the alarm threshold will align correctly with actual cell state.