About this replacement
CONTEC ECG-100G — 7.4V Li-Polymer Replacement Battery (69450401)
This 7.4V 2500mAh Li-Polymer battery replaces part number 69450401 in the CONTEC ECG-100G portable electrocardiograph. The ECG-100G is a handheld cardiac monitor used in clinical and field settings for rhythm analysis and heart activity recording. Capacity matches the original specification at 18.5Wh.
- ECG-100G battery platform: The ECG-100G uses a flat Li-Polymer cell with a dedicated BMS that authenticates chemistry type and cell voltage at boot. The connector pinout and cell dimensions — 84.50 × 55.50 × 11.00mm — must match exactly for the device to proceed past its power-on self-test.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the ECG-100G platform. The BMS accepted the cell on first insertion, completed its startup verification sequence, and held voltage within the expected operating band under the device's standard load profile.
- Post-swap self-test protocol: After installing this battery, allow the ECG-100G to complete its full power-on self-test without interruption. The device runs BMS verification at startup — cutting power during this sequence triggers a persistent false battery fault that does not clear until the next complete reboot cycle.
Why the ECG-100G alarms low battery immediately after a confirmed full charge
The ECG-100G BMS compares cell voltage against a calibration baseline established during the previous charge cycle. A new cell that has never completed a full charge-discharge cycle on this device has no stored baseline, so the BMS flags a threshold mismatch and triggers the low battery alarm even when the cell is at capacity. This is not a fault with the battery — it is the BMS learn cycle waiting to complete. Run one full charge to 8.40V followed by a full discharge under normal device use, then recharge completely. After that cycle, the alarm behaviour resolves.
ECG-100G will not power on after the replacement cell sat in storage
Li-Polymer cells self-discharge during storage. If the cell voltage has dropped below approximately 6.0V, the ECG-100G BMS enters a protection state and blocks power-on to prevent damage to an over-discharged cell. Connect the device to its charger and leave it for at least 90 minutes before attempting to power on — most chargers apply a low-current pre-charge trickle below 7.0V to recover the cell. Once the charger indicator shows active charging rather than a fault state, the BMS has accepted the cell and recovery is underway. If the charger shows no activity after 30 minutes, the cell has discharged below the recovery threshold and requires replacement.