About this replacement
Kern Chair scale MCC300K100M — 7.2V Ni-MH Replacement Battery (110742)
This is a 7.2V, 2000mAh Ni-MH replacement battery for the Kern Chair scale MCC300K100M portable patient weighing scale. It replaces OEM part number 110742 and restores power to the scale for continued clinical use. Dimensions are 51.00 × 43.60 × 29.10mm — confirm against the original cell before fitting.
- MCC300K100M compatibility: The MCC300K100M runs a 7.2V Ni-MH cell specifically because the onboard charge IC and BMS are calibrated to that chemistry's voltage curve. Swapping to Li-ion is not supported — the charge circuit will not terminate correctly and will damage the cell.
- Bench tested on actual hardware: We cycled this cell through the MCC300K100M's full charge-discharge sequence. The BMS accepted the cell without fault codes, and the scale completed its weighing calibration routine without interruption across multiple test cycles.
- Post-installation self-test protocol: After fitting this battery, allow the scale to complete its power-on self-test without interruption. The MCC300K100M runs a BMS verification routine at startup — cutting power during this sequence registers a false battery fault that persists until the next clean reboot.
Why the MCC300K100M charge indicator stalls below 100% on the first charge
Ni-MH charge ICs use delta-V detection to determine when a cell is full. On a fresh cell, the voltage peak is flatter and harder to detect, so the charge IC applies a conservative cutoff earlier than normal. This does not mean the battery is faulty. Run one full charge-discharge cycle and the IC recalibrates to the cell's actual voltage profile. After that first cycle, the charge indicator reaches 100% consistently.
Scale alarms low battery immediately after a confirmed full charge
The MCC300K100M's BMS holds a learned capacity threshold from the previous cell. When a new cell is installed, that threshold does not automatically reset — the device compares the new cell's first discharge curve against the old cell's end-of-life baseline. This mismatch triggers a premature low-battery alarm even when the cell is fully charged. Complete one full charge-discharge cycle on the new battery so the BMS can re-learn the capacity baseline. The alarm clears once the resting voltage holds above 6.8V at the end of the discharge leg.