Dego Cardiomed 3 ECG Compatible Battery 9.6V 1700mAh

Dego Cardiomed 3 ECG — 9.6V Ni-MH Replacement Battery (120122)

This is a 9.6V, 1700mAh Ni-MH battery for the Dego Cardiomed 3 ECG portable electrocardiograph. It replaces OEM part numbers 120122 and BATT/110122. The Cardiomed 3 ECG is a clinical-grade cardiac monitoring device used in ambulatory and point-of-care settings, so battery reliability directly affects patient workflow continuity.

• Cardiomed 3 ECG fit: The Cardiomed 3 platform uses a fixed 9.6V Ni-MH cell pack with a specific connector and BMS handshake tied to that voltage rail. This replacement matches the same cell configuration, connector pinout, and charge termination profile the device expects.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the bench. The BMS accepted the new pack without flagging a chemistry mismatch, and charge termination fired correctly at full capacity. Voltage held steady across the load profile typical of an ECG trace acquisition cycle.
• Post-swap self-test protocol: After fitting this battery, let the Cardiomed 3 complete its full power-on self-test without pressing any keys or interrupting the boot sequence. The device runs a BMS verification at startup, and cutting that sequence short causes a persistent false battery fault that clears only on a full cold reboot.

Why the Cardiomed 3 alarms low battery immediately after a confirmed full charge

The Cardiomed 3 BMS uses threshold values calibrated against the original OEM cell's internal resistance and charge curve. A new replacement cell has a slightly different charge profile in its first few cycles, which can sit outside the BMS acceptance window at startup. The device interprets this as a low-charge condition even when the cell is physically full. One complete charge-discharge cycle on the new pack recalibrates the BMS read and clears the false alarm.

Cardiomed 3 not powering on after the replacement battery sat in storage

Ni-MH cells self-discharge at roughly 1–3% per day, so a battery stored for several weeks can drop below the BMS recovery threshold — typically around 8.4V on a 9.6V pack. Below that voltage, the device BMS blocks startup as a protection measure and the unit appears dead. Connect the Cardiomed 3 to mains charge and leave it for a minimum of 15 minutes before attempting to power on. Once voltage recovers above 8.4V, normal boot resumes.