Eufy Omni C20 Replacement Battery 14.4V 3400mAh

Eufy Omni C20 Robot Vacuum — 14.4V Li-ion Replacement Battery (C0914G)

This is a 14.4V, 3400mAh lithium-ion battery for the Eufy Omni C20 robot vacuum. It replaces OEM part numbers C0914G and T290H. When the original cell degrades and cleaning sessions shorten or suction drops, this cell restores the vacuum to full operating capacity.

• Omni C20 platform fit: The Omni C20 runs a 14.4V motor rail with a BMS handshake on startup. This cell matches that voltage, connector pinout, and communication protocol — the vacuum powers on and runs cleaning cycles without error codes.
• Bench tested on actual hardware: We cycled this cell through full charge-discharge sequences on the Omni C20 platform. The BMS balanced cells correctly across all cycles and the overcurrent protection tripped at the expected threshold under a restricted-airflow load test.
• Dock charging behaviour on the Omni C20: Do not leave the Omni C20 sitting on its dock permanently between uses. The dock applies a continuous trickle charge once full, which degrades cell capacity faster than standard charge cycles. Charge the battery to full, then remove it from the dock until the next scheduled use.

Suction dropping before the battery indicator reaches low

On the Omni C20, suction loss under a partial blockage or a clogged filter hits the battery before the indicator catches up. A restricted airflow path forces the motor to draw more current than rated, which causes voltage sag on the cell even when charge level still reads mid-range. The BMS reads this voltage drop as a low-cell condition and begins reducing motor power to protect the pack. Clear the filter and check the brush roller before swapping the battery — a clean airflow path is the first diagnostic step.

Motor cutting out and self-recovering mid-cycle

If the Omni C20 motor cuts out for a few seconds and then resumes on its own, this is the BMS tripping an overcurrent fault and resetting. This happens when sustained restricted suction — usually a packed filter or tangled brush roller — pushes draw above the BMS cutoff threshold. It is not a faulty battery. Clean the filter and roller, then resume the cycle. If the cutout continues after the airflow path is clear, check that cell voltage at rest sits above 12.5V before charging.