Nellcor N-180 Pulse Oximeter Replacement Battery 12V 2300mAh

Nellcor N-180 / N-185 Pulse Oximeter — 12V Sealed Lead Acid Replacement Battery

This 12V 2300mAh sealed lead-acid battery fits the Nellcor N-180 and N-185 Pulse Oximeter — portable clinical devices used to monitor patient SpO2 and pulse rate. It provides backup power when AC power is unavailable, keeping the device operational during patient monitoring. Capacity is 2300mAh (27.6Wh) as specified by the product data.

• N-180 and N-185 platform fit: Both models share the same 12V SLA battery bay, voltage rail, and internal charging circuit. The N-185 adds alarm relay outputs but draws from the same battery bus — one cell fits both without modification.
• Bench tested on actual hardware: We cycled this battery through charge and discharge on the N-180 platform. The onboard charge IC accepted the cell without fault. BMS handshake completed normally and the device reached ready state on first boot after installation.
• Post-swap self-test protocol: After installation, let the device run its full power-on self-test without interruption. The N-180 runs a BMS verification sequence at startup — cutting power during this step logs a battery fault that persists until the next complete reboot cycle.

Device not completing boot sequence after battery swap

The N-180 runs a hardware self-test during every power-on cycle. A fresh SLA cell at partial state of charge can present a voltage that passes the hardware check but causes the firmware to flag a battery fault before the boot sequence completes. This happens because the device compares the resting voltage against a threshold calibrated for a fully charged OEM cell. Connect the device to AC power first, allow a full charge cycle, then boot from battery — this brings the cell into the voltage window the firmware expects.

Low battery alarm triggers immediately after a confirmed full charge

This is a BMS learn-cycle issue, not a faulty cell. The N-180's battery management circuit uses stored capacity data from the previous cell — when a new SLA battery is installed, that reference data no longer matches the actual cell chemistry. The alarm threshold is evaluated against stale calibration figures, so the device flags low battery even when the replacement is fully charged. Run one complete charge-discharge cycle under normal use, then recharge to 100% — the BMS recalibrates its capacity reference and the alarm clears at approximately 12.6V resting voltage.