About this replacement
Fukuda FX-2111 / FCP-2155 / FX-2155 — 9.6V Ni-MH Replacement Battery (HHR-13F8G1)
This is a 9.6V, 2000mAh Ni-MH replacement battery for the Fukuda FX-2111, FCP-2155, and FX-2155 electrocardiograph machines. It replaces OEM part numbers HHR-13F8G1 and 8-HRAAFD. These are portable cardiac diagnostic devices used in clinical settings to capture and record cardiac electrical activity.
- FX-2111, FCP-2155, and FX-2155 compatibility: All three models share the same 9.6V battery rail, connector pinout, and BMS handshake protocol. A single cell pack services the full range without modification.
- Bench tested on actual hardware: We ran this cell through the FX-2111 charge cycle and monitored BMS communication at each stage. The pack cleared OEM charge thresholds and passed the device's internal battery verification routine on the second full cycle.
- Post-installation self-test protocol: After fitting this battery, allow the device to complete its full power-on self-test without interruption. The FX-2111 runs a BMS verification sequence at startup — cutting power mid-sequence flags a false battery fault that persists until the next complete reboot cycle.
Why the FX-2111 reports low battery immediately after a confirmed full charge
The FX-2111 charge IC compares cell voltage against a threshold calibrated for the OEM cell's internal resistance profile. A new replacement cell has a slightly different resistance curve in the first few cycles, which causes the BMS to under-report state-of-charge. The alarm clears after one complete charge-discharge cycle lets the BMS re-map the cell. Do not use the device clinically until that calibration cycle is complete.
FX-2111 failing to complete boot sequence after the battery sat in storage
Ni-MH cells self-discharge at roughly 1–2% per day at room temperature. A pack stored for several months can drop below 8.0V — the minimum voltage the FX-2111 BMS requires to initiate boot. At that point the device will not power on at all, even with the charger connected. Place the battery on charge for a minimum of four hours before attempting to power the device. If the pack recovers above 9.0V and holds, it will complete the boot sequence normally.