Fukuda FL-1B ECG Replacement Battery 3.7V 1800mAh

Fukuda EK-168G / EK-268G / EK-468G — 3.7V Li-ion Replacement Battery (FL-1B)

The FL-1B is a 3.7V Li-ion cell rated at 1800mAh (6.66Wh) for the Fukuda EK-168G, EK-268G, and EK-468G portable electrocardiograph units. These are clinical-grade ECG devices used in ward rounds, field cardiac surveys, and outpatient settings. This replacement restores power when the original cell no longer holds a usable charge.

• EK-168G / EK-268G / EK-468G platform fit: All three models share the same battery bay geometry, connector pinout, and BMS handshake protocol — the FL-1B spans the full series without modification.
• Bench tested on actual hardware: We ran the pack through full charge cycles and confirmed the BMS negotiates correctly with the ECG unit's charge controller — no false low-battery flags, no mid-trace shutdowns under lead load.
• Post-install calibration on the EK series: After fitting a new cell, run the unit through one complete recording session before clinical use. The EK series maps battery state during active operation, and skipping this step causes the on-screen charge indicator to misreport capacity on the first patient session.

BMS lockout after the EK-168G sat unused in a carry case for months

Li-ion cells in portable ECG units self-discharge slowly during storage. If the pack drops below approximately 2.5V, the BMS trips a protection latch and the unit appears completely dead — not just flat. The charger sees a near-zero voltage cell and refuses to initiate a charge cycle. Connecting the unit to its OEM charger for 20–30 minutes at low current is usually enough to bring the cell above the 2.9V recovery threshold and unlock the BMS. If the indicator light never changes state after that window, the original cell has reached end of life and requires this replacement.

ECG trace resets or freezes mid-recording during a multi-lead session

When the EK series powers all twelve leads simultaneously, the combined current draw spikes well above standby load. An aged or marginal cell voltage sags under that draw, crossing the BMS undervoltage threshold even though the display showed adequate charge beforehand. The BMS cuts output to protect the cell, the unit resets, and the trace is lost. This is not a firmware fault — it is a cell capacity problem. Fit a fresh FL-1B and verify the terminal voltage reads at or above 3.7V before the next recording session.