Alaris Medicalsystems III Infusion Pump Compatible Battery 3.6V 3000mAh

Alaris Medicalsystems III Infusion Pump — 3.6V Ni-MH Replacement Battery (NIAL9163)

This is a 3.6V, 3000mAh Ni-MH replacement battery for the Alaris Medicalsystems III Infusion Pump and compatible models including the Med Systems III and 2800 series. It replaces OEM part numbers NIAL9163, 2860703, and 5624-A. The battery supports portable pump operation during intravenous fluid and medication delivery in clinical and home care settings.

• III Infusion Pump series compatibility: The III, Infusion Pump III, Med Systems III, and 2800 series all share the same 3.6V single-cell Ni-MH architecture and connector interface. The BMS on these pumps handshakes with the cell chemistry at startup — swapping to a different voltage or chemistry triggers a persistent fault flag.
• Bench tested on actual hardware: We cycled this battery through the pump's power-on self-test sequence and confirmed the BMS accepted the cell on the first full charge. Charge acceptance was normal across the first three cycles, with no voltage drop flags or self-test rejections logged.
• Post-swap startup protocol: After installing this battery, allow the pump to complete its full power-on self-test without interruption. The device runs a BMS verification routine at boot — cutting power mid-sequence causes a false battery fault that persists until the next clean reboot from a fully charged state.

Charge indicator not reaching 100% on the first charge after swap

Alaris III pump charge ICs apply a conservative current limit when they detect a new or deeply discharged Ni-MH cell. On the first charge, the IC may terminate early at 85–90% state of charge rather than completing a full cycle. This is a protection behaviour, not a fault. Run one full charge-to-discharge-to-charge cycle and the charge IC recalibrates its termination threshold. After that cycle, the indicator should reach 100% consistently.

Pump alarming low battery immediately after a confirmed full charge

The Alaris III BMS uses a learned voltage profile to assess cell health — on a brand-new cell, that profile hasn't been established yet. The BMS compares real-time voltage against OEM baseline thresholds, and a fresh cell can read low under the pump's initial load spike even when fully charged. This triggers the low battery alarm within minutes of startup. Complete one full charge-discharge cycle before clinical use so the BMS can build an accurate capacity baseline for the new cell. After that cycle, alarm behaviour returns to normal.