About this replacement
COMEN C11 / CM300 / M200 Series — 11.1V Li-ion Replacement Battery (022-000113-00)
This 11.1V 3400mAh Li-ion battery replaces the OEM pack in COMEN patient monitors including the C11, CM300, M200, and M200a. It is a direct cell replacement for portable vital signs monitors used in clinical and transport settings. Voltage and capacity match OEM spec — 11.1V nominal, 37.74Wh.
- C11, CM300, M200, M200a platform compatibility: These monitors share the same 11.1V three-cell Li-ion architecture, connector pinout, and BMS communication protocol — one battery pack serves the full family without modification.
- Bench tested on actual hardware: We cycled this pack through the C11's power-on self-test and charge IC handshake. The BMS accepted the cell chemistry, reported state-of-charge correctly, and held the charge curve within OEM tolerance across discharge.
- Post-installation self-test protocol: After fitting this battery, allow the C11 to complete its full power-on self-test without interruption. The device runs a BMS verification sequence at startup — cutting power during this window creates a persistent false battery fault that clears only on the next complete reboot.
Why the C11 alarms low battery immediately after a confirmed full charge
The C11's charge IC applies a conservative state-of-charge threshold calibrated to the OEM cell's internal resistance profile. A new replacement cell has a slightly different impedance signature on the first cycle, which causes the BMS to interpret capacity as lower than actual. Run one full charge-discharge cycle before clinical deployment. After that cycle, the BMS recalibrates and the low-battery threshold aligns correctly with the new cell's real capacity curve.
Device will not power on after battery sat unused in storage
Li-ion cells self-discharge during storage at roughly 1–3% per month. If the pack drops below the C11's BMS recovery threshold — typically around 9V for an 11.1V three-cell pack — the monitor will not boot because the BMS locks out discharge to protect the cells. Connect the device to mains AC power first and allow it to charge for at least 20 minutes before attempting to power on. This pre-charge brings the cell voltage above the BMS unlock threshold and restores normal startup.