About this replacement
Fukuda Cardisuny C300 — 9.6V Ni-MH Replacement Battery (8NC-1800SCE-SC)
This is a 9.6V 3000mAh Ni-MH replacement battery for the Fukuda Cardisuny C300 portable cardiac monitor and electrocardiograph. It fits directly in place of the original cell pack and restores power to the device during patient examinations and ECG data collection. Capacity is 3000mAh (28.8Wh), matching the standard configuration used in clinical settings.
- Cardisuny C300 fit: The C300 uses a 9.6V Ni-MH pack with a specific cell arrangement and connector that matches OEM part numbers 8NC-1800SCE-SC, P-18R/L42G1, 8NC1800SCE, and 8NC-1900SCR. The BMS in this device reads voltage and temperature from the pack — the cell chemistry and nominal voltage must match exactly for the charge controller to accept the battery.
- Bench tested on actual hardware: We cycled this pack through full charge-discharge runs on the C300 platform. The BMS accepted the battery on initial insertion, completed its startup verification sequence, and the charge indicator progressed normally. No fault codes were triggered after the first full cycle.
- Post-swap self-test protocol: After installing this battery, allow the C300 to complete its full power-on self-test without interrupting or powering down the device mid-sequence. The C300 runs a BMS verification check at startup — cutting power during this window logs a battery fault that persists until the next clean boot cycle.
Why the C300 charge indicator stalls below 100% on the first charge
The C300 charge IC applies a conservative charge ceiling when it detects a new or cold cell — it limits current and terminates early to protect the pack on the first cycle. This is normal behaviour with fresh Ni-MH cells and is not a fault with the battery or charger. After one full charge-discharge cycle, the charge controller recalibrates its termination threshold and the indicator will reach 100% on subsequent charges. Do not assume the battery is defective because the first charge reads short.
C300 alarms low battery immediately after a confirmed full charge
The C300's BMS holds a voltage reference calibrated to the capacity curve of the original OEM cell. A new replacement cell has a slightly different internal resistance profile during the first several cycles, which can cause the BMS to read the voltage as below threshold even when the pack is fully charged. Run one complete charge-discharge-charge cycle before clinical use — this allows the BMS to update its reference point against the actual cell behaviour. After that conditioning cycle, the low-battery alarm clears and the device reads charge state accurately.