EDANINS ECG-1A Replacement Battery 12V 2000mAh Ni-MH

EDANINS ECG-1A — 12V Ni-MH Replacement Battery

This is a 12V, 2000mAh Ni-MH replacement battery for the EDANINS ECG-1A portable electrocardiogram monitor. It fits the ECG-1A directly and restores power to the unit for cardiac rhythm capture and display. Voltage and capacity match OEM specifications: 12V, 2000mAh (24Wh).

• ECG-1A platform fit: The ECG-1A uses a 12V Ni-MH cell pack with a specific connector and BMS handshake tied to that chemistry. Swapping to Li-ion would trigger a charge fault — this cell keeps the correct voltage curve and charge termination behaviour the device expects.
• Bench tested on actual hardware: We cycled this battery through the ECG-1A's charge IC and confirmed the BMS accepted the cell without fault codes. The charge termination fired correctly at full capacity, and the device passed its power-on self-test without interruption.
• Post-installation self-test protocol: After fitting this battery, let the ECG-1A complete its full power-on self-test cycle without cutting power. The device runs BMS verification at startup — interrupting it locks in a false battery fault that persists until the next clean reboot.

Why the ECG-1A flags a low battery warning on a freshly charged new cell

The ECG-1A's BMS stores a charge threshold calibrated to the OEM cell's internal resistance profile. A new replacement cell has a slightly different resistance curve until it's been through at least one full charge-discharge cycle. On the first use, the BMS reads this mismatch as a capacity shortfall and triggers the low battery alarm even at full charge. Run one complete charge-discharge cycle before using the device clinically — the BMS recalibrates on that cycle and the alarm clears.

ECG-1A won't power on after the battery sat unused in storage

Ni-MH cells self-discharge at roughly 1–2% per day at room temperature. A cell stored for several months can drop below the BMS recovery threshold — typically around 10V on a 12V Ni-MH pack — at which point the ECG-1A's protection circuit blocks power-on to prevent damage. Connect the battery to the charger and leave it for a full charge cycle without attempting to power on the device. Once the pack reaches approximately 13.2V fully charged, the BMS re-enables the output and the device will boot normally.