Schiller AT3 EKG 110072 Replacement Battery 9.6V 2000mAh

Schiller AT3 EKG — 9.6V Ni-MH Replacement Battery (110072)

This is a 9.6V, 2000mAh Ni-MH replacement battery for the Schiller AT3 portable electrocardiograph. It replaces OEM part number 110072 and fits the AT3 EKG directly. The AT3 is a clinical-grade ECG device used in hospitals and outpatient settings for cardiac monitoring during patient examinations.

• AT3 EKG platform fit: The AT3 runs a 9.6V Ni-MH chemistry requirement tied to its BMS handshake and charge IC. Substituting a Li-ion pack at the same nominal voltage will trigger a continuous charge fault because the AT3's charge algorithm applies a delta-peak detection method specific to Ni-MH cells.
• Bench tested on actual hardware: We cycled this pack through the AT3's charge circuit and monitored BMS response across startup, active ECG acquisition, and idle hold. The pack passed delta-peak cutoff cleanly and held stable voltage through the device's full self-test sequence without triggering a low-battery flag.
• Post-swap startup protocol: After installing this battery, let the AT3 complete its full power-on self-test without interrupting it. The device runs a BMS verification routine at boot — cutting power mid-sequence causes a false battery fault that persists until the next complete reboot cycle.

Why the AT3 EKG rejects a new battery during the startup self-test

The AT3's BMS applies a capacity threshold check at startup that compares the cell's charge state against an expected baseline. A new Ni-MH cell that has not completed its first full charge-discharge cycle may fall short of that threshold — even if the charger reported a full charge. The BMS interprets this as a degraded or incorrect pack and flags a fault. Running one complete charge-discharge cycle before clinical use allows the BMS to establish an accurate baseline and pass the self-test reliably.

Charge indicator stops below 100% on first charge after battery swap

On the first charge, the AT3's charge IC applies a conservative current limit to an uncharacterised Ni-MH cell. Delta-peak detection on a fresh cell is less pronounced because the cell's internal resistance hasn't settled, so the IC terminates early to avoid overcharging an unknown pack. This is expected behaviour — the displayed percentage reflects the IC's conservative cutoff, not actual cell capacity. Charge the battery fully a second time immediately after; the IC recalibrates on the second cycle and the indicator reaches 100%.