About this replacement
CONTEC ECG-600G — 7.4V Li-Polymer Replacement Battery (855183P-2S)
This 7.4V 3800mAh Li-Polymer battery replaces the CONTEC part number 855183P-2S in the ECG-600G portable electrocardiograph. It fits the ECG-600G used in clinical and mobile cardiac monitoring workflows. Voltage and cell chemistry match the original specification at 7.4V and 28.12Wh.
- ECG-600G platform fit: The ECG-600G runs a fixed 7.4V two-cell Li-Polymer configuration with a BMS handshake tied to cell chemistry. Swapping to a different voltage or cell format breaks that handshake and triggers a persistent battery fault on the device.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the ECG-600G platform. The BMS accepted the cell, completed its verification pass, and reported state-of-charge accurately across the discharge curve.
- Post-swap power-on sequence: After installing this battery, let the ECG-600G complete its full power-on self-test without interruption. The device runs a BMS verification step at startup — cutting power during this window causes a false battery fault that persists until the next clean reboot.
ECG-600G not completing boot sequence after battery swap
The ECG-600G runs a startup self-test that includes a BMS handshake before the main interface loads. A new cell that has not completed its first full charge cycle may sit just below the voltage threshold the device expects at boot. The device interprets this as a fault and halts the sequence. Charge the battery fully before the first installation — confirm the charger has reached 8.4V before fitting the cell.
Charge indicator stalling below 100% on first charge
On the first charge, the ECG-600G charge IC applies a conservative current limit to a new Li-Polymer cell it has not previously profiled. This causes the charge indicator to plateau at 90–95% and stall for an extended period before completing. This is normal behaviour on the first cycle and resolves after one full charge-discharge pass. Do not interrupt the charge — let the cycle finish completely so the charge IC can update its cell model.