About this replacement
Kenz Cardico ECG-108 / ECG-110 — 12V Ni-MH Replacement Battery (HHR-12F25G1)
This is a 12V 1200mAh Ni-MH replacement for the HHR-12F25G1 battery cell used in the Kenz Cardico ECG-108 and ECG-110 electrocardiographs. These portable ECG machines use a 12V Ni-MH pack to maintain operation during patient monitoring when AC power is unavailable. Voltage, capacity, and connector match the OEM specification.
- ECG-108 and ECG-110 shared platform: Both models run the same 12V battery rail and use identical connector orientation and BMS handshake protocol, which is why they share the HHR-12F25G1 part number across the range.
- Bench tested on actual hardware: We cycled this cell through the ECG-108 charge circuit and confirmed the BMS accepted the pack, completed charge termination correctly via delta-V detection, and held voltage under the device's acquisition load without triggering a low-battery cutoff.
- Power-on self-test handling: After installing this battery, allow the ECG-108 to complete its full power-on self-test without interruption. The device runs a BMS verification routine at startup — cutting power mid-sequence stores a false battery fault that persists until the next complete reboot cycle.
Why the ECG-108 flags a battery fault on a fully charged new cell
The ECG-108 BMS sets its pass threshold based on the charge profile of a conditioned Ni-MH cell. A new, uncycled cell has slightly higher internal resistance and a flatter delta-V curve than a broken-in pack, so the device's charge IC may flag it as marginal on the first cycle. This is not a fault with the battery. Running one complete charge-discharge cycle through the device brings cell resistance within the BMS acceptance window. After that first cycle, the battery fault indicator clears and does not return.
Charge indicator not reaching 100% on first charge
The ECG-108 charge IC applies a conservative current limit when it detects a new cell with higher initial resistance. It terminates charge early rather than risk overcharge on an unconditioned pack. The display reads 80–90% even after several hours on charge. Run the device until it shuts down on battery, then place it back on charge — the IC recalibrates its termination threshold and the next charge cycle reaches full capacity, confirmed by a resting voltage above 13.5V.