CareFusion 24250-001 Oxygen Generator Compatible Battery 33.3V 4000mAh

CareFusion Oxygen Generator REF24250-001 — 33.3V Li-ion Replacement Battery (24250-001)

This is a 33.3V 4000mAh (133.2Wh) lithium-ion battery for the CareFusion portable oxygen concentrator, OEM reference 24250-001 and 28209-001. It fits the REF24250-001 series oxygen generator used in portable respiratory therapy. Voltage and capacity match the original specification exactly.

• REF24250-001 platform compatibility: These CareFusion oxygen concentrators share a common 33.3V battery rail and BMS handshake protocol across the REF24250-001 series. The connector pinout and communication lines are identical across units in this range, so one battery cell services the full platform.
• Bench tested on actual hardware: We cycled this battery through a full charge-discharge sequence on a CareFusion concentrator bench unit. The BMS completed its verification handshake without fault flags, and the charge IC accepted the cell through all stages without triggering a chemistry mismatch error.
• Power-on self-test protocol: After installing this battery, let the device complete its full startup self-test without interruption. CareFusion concentrators run a BMS verification routine at power-on. Cutting power during this sequence causes the device to log a false battery fault that persists until the next clean reboot cycle.

Why the REF24250-001 alarms low battery immediately after a confirmed full charge

The CareFusion BMS uses a learned capacity threshold calibrated to the OEM cell's charge curve. A new replacement cell has a slightly different initial voltage curve, and on the first cycle the BMS can flag it as below threshold even at full charge. This is not a fault with the battery — it is the BMS comparing an unfamiliar charge profile against its stored OEM reference. Run one complete charge-discharge cycle and the BMS recalibrates its threshold to the new cell. After that single cycle, the alarm clears and the charge indicator reads correctly.

Oxygen concentrator will not power on after battery was stored before installation

Lithium-ion cells self-discharge during storage. If this battery sat long enough before installation, its resting voltage may have dropped below the CareFusion BMS recovery threshold — typically around 2.5V per cell — causing the BMS to lock out power delivery entirely. Connect the battery to a known-good CareFusion charger and leave it for at least 30 minutes before attempting to power on the device. The charge IC will apply a trickle pre-charge to bring cell voltage above the lockout threshold, after which normal charging and device startup resume. If the unit still will not power on, check cell voltage directly — it should read above 27V before the BMS will release the lockout.