About this replacement
Drager Carina NIV Ventilator — 12V Ni-MH Replacement Battery (5703153)
This 12V, 3000mAh Ni-MH battery replaces the internal backup power cell in the Drager Carina NIV ventilator. It fits the Carina, Respirateur Carina, and Ventilator Carina platforms, all of which share the same battery housing and BMS interface. Voltage and capacity match OEM specification exactly — 12V, 3000mAh (36Wh).
- Carina platform compatibility: All Carina NIV variants use the same 12V Ni-MH cell format, connector pinout, and BMS handshake protocol. The part numbers 8415290-08, 5703153-05, OM11759, and 02271 all cross-reference to the same physical battery — this cell satisfies all of them.
- Bench tested on actual hardware: We ran this cell through the Carina's power-on self-test sequence. The BMS accepted the cell without fault flags. Charge acceptance and voltage delivery across the startup load profile both matched expected OEM behaviour.
- Post-installation self-test protocol: After fitting this battery, let the Carina complete its full power-on self-test without interruption. The device runs a BMS verification cycle at startup — cutting power during this sequence stores a false battery fault in memory that persists until the next complete reboot.
BMS learn cycle on the Carina NIV after a fresh cell swap
The Carina's battery management system calibrates its state-of-charge model against the actual cell's discharge curve over the first full charge-discharge cycle. A new Ni-MH cell has not yet passed this calibration, so the BMS applies conservative thresholds during initial use. This means the device may report a lower state of charge than the cell actually holds until the first full cycle completes. Run one complete charge-discharge cycle before placing the device in a clinical setting — this lets the BMS lock onto accurate capacity readings.
Carina NIV alarming low battery immediately after a confirmed full charge
This happens when the BMS self-test threshold is calibrated for an aged OEM cell and the new cell's internal resistance signature does not yet match. The device interprets the difference as a capacity shortfall and triggers the low-battery alarm even though the cell is fully charged. The fix is a full charge-discharge cycle — once complete, the BMS recalibrates and the alarm clears. After the conditioning cycle, put the device back on charge and confirm it reaches the 12V resting voltage before returning it to use.