About this replacement
Biocare ECG-1200 Series — 14.8V Li-ion Replacement Battery (HYLB-683)
This 14.8V, 2600mAh Li-ion battery replaces the OEM pack in the Biocare ECG-1200, ECG-1201, and ECG-1210 portable electrocardiograph. It fits the same connector and BMS handshake point as the original HYLB-683 and HYLB-293 packs. Capacity is 2600mAh (38.48Wh) — matched to the original specification.
- ECG-1200 / ECG-1201 / ECG-1210 platform: All three models run the same 14.8V four-cell series architecture with an identical battery bay and BMS communication line. One pack covers the full range because the voltage rail, connector pinout, and charge termination logic are shared across the series.
- Bench tested on actual hardware: We cycled this cell through the ECG-1200 charge circuit and monitored BMS handshake signals at each stage. The pack completed charge termination cleanly and passed the device's internal cell-verification routine without fault codes.
- Post-swap startup protocol: After installing this battery, let the ECG-1200 complete its full power-on self-test without interruption. The device runs a BMS verification sequence at boot — cutting power during this window forces a false battery fault that stays flagged until the next complete reboot cycle.
Why the ECG-1200 logs a battery fault on the first charge cycle
The ECG-1200 charge IC applies a conservative acceptance threshold calibrated to a known, aged OEM cell chemistry. A new replacement cell presents slightly different internal resistance, so the charge controller may flag a fault or hold at a reduced charge limit on the first cycle. This is not a defect — it is the BMS establishing a baseline for the new cell. One complete charge-to-discharge-to-full-charge cycle resets the learned parameters and clears the fault state.
Charge indicator stuck below 100% after first full charge
New cells fresh from storage often carry a partial charge that confuses the coulomb counter in the ECG-1200's battery management circuit. The counter calculates state-of-charge from a known-full reference point — if it never saw the cell hit the true 4.2V-per-cell ceiling, its 100% reference is off. Run one full charge from near-empty to a confirmed green charge light, then discharge the device through normal use before charging again. After that cycle the indicator tracks correctly.