About this replacement
COMEN NC8 — 11.1V Li-ion Replacement Battery (022-000142-00)
This is an 11.1V, 2600mAh Li-ion battery for the COMEN NC8 portable patient monitor. It replaces OEM part number 022-000142-00. The NC8 is a bedside vital signs monitor used in clinical and transport settings where AC power is not always available.
- NC8 monitor compatibility: The NC8 uses a dedicated battery bay with a three-cell 11.1V Li-ion configuration. The BMS on this monitor checks cell voltage at startup and communicates charge state to the display. Voltage, connector type, and BMS handshake all match the OEM specification.
- Bench tested on actual hardware: We ran this cell through the NC8 boot sequence and confirmed the BMS completed its initialisation cycle without fault. The charge IC accepted the cell on first connection and reported state-of-charge correctly on the monitor's battery indicator.
- Post-swap power-on sequence: After installing this battery, let the NC8 complete its full power-on self-test without interruption. The monitor runs a BMS verification step at startup. Cutting power during that sequence logs a battery fault that will persist until the next clean reboot cycle.
Why the NC8 shows a battery fault after a confirmed full charge
The NC8's BMS compares cell impedance against stored OEM thresholds during startup. A new cell that has not yet completed a full charge-discharge cycle will have slightly higher impedance than an aged OEM cell the monitor expects. This can trigger a fault flag even when the cell is at full voltage. One complete charge-to-discharge cycle lets the BMS recalibrate its learned capacity value and clear the fault on the next boot.
NC8 will not power on after the battery sat unused in storage
Li-ion cells self-discharge during storage, and if the cell voltage drops below approximately 2.5V per cell — around 7.5V for a three-cell 11.1V pack — the NC8's BMS will refuse to start a charge cycle as a protection measure. Connect the monitor to AC power and leave it on charge for at least two hours before attempting to power on. Most BMS circuits include a trickle pre-charge mode that will recover a low-voltage cell up to the minimum threshold, after which normal charging resumes.