IKO3 HeartMirror ECG Compatible Battery 6V 1500mAh E-1513

IKO3 HeartMirror ECG — 6V Ni-MH Replacement Battery (E-1513)

This is a 6V, 1500mAh Ni-MH replacement battery for the IKO3 HeartMirror ECG and HeartMirror EKG portable cardiac monitors. It matches OEM part number E-1513 and fits directly into either device variant without modification. Capacity is 1500mAh (9Wh), sourced to match the original cell specification.

• HeartMirror ECG and EKG compatibility: Both the ECG and EKG variants use the same 6V cell architecture and E-1513 connector footprint. The BMS handshake protocol and charge termination voltage are shared across both models, so one cell works in either unit.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the HeartMirror platform and confirmed the BMS accepted the new Ni-MH cell without fault codes. Charge termination fired correctly at the delta-V threshold, and the device passed its internal self-test sequence on each power-on.
• Post-swap power-on sequence: After installing this battery, let the device complete its full power-on self-test without interrupting it. The HeartMirror runs a BMS verification routine at startup — cutting power during this window triggers a battery fault flag that persists until the next full reboot cycle.

Why the HeartMirror ECG reports a battery fault on a fully charged new cell

The HeartMirror's charge IC applies a conservative internal capacity threshold during its first validation cycle on a new Ni-MH cell. Fresh cells arrive partially discharged, and the BMS compares charge acceptance against a stored baseline calibrated to the original OEM cell's break-in state. If the new cell hasn't completed at least one full charge-discharge cycle, the BMS may flag a fault even when the cell is at full voltage. Run one complete charge and discharge cycle before using the device clinically — the fault clears once the BMS has logged a valid cycle.

Charge indicator not reaching 100% on first charge

On the first charge after fitting a new Ni-MH cell, the HeartMirror's charge controller applies a reduced charge ceiling. This is a deliberate behaviour — the charge IC limits peak voltage on an unrecognised cell to prevent overcharge on an unknown capacity baseline. The display may stall at 85–95% and hold there. Let the charge cycle run to completion without interruption; the controller releases the ceiling and tops the cell to full voltage by the end of the cycle. Confirm full charge by checking the cell voltage — it should read 7.2V at termination on Ni-MH chemistry.