About this replacement
Cecotec Conga 4090 / 4490 / 4690 — 14.4V Li-ion Replacement Battery (49CE5402)
This 14.4V 5200mAh (74.88Wh) lithium-ion battery replaces the original pack in the Cecotec Conga 4090 and related Conga 4000-series robotic vacuums. It fits the Conga 4490, 4590, and 4690 as well. When the stock battery loses charge capacity or stops holding a cycle, this cell restores the robot to full operating condition.
- Conga 4000-series platform fit: The 4090, 4490, 4590, and 4690 share the same 14.4V battery bay, connector pinout, and BMS handshake protocol. One replacement cell covers all four variants without modification.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the Conga platform. The BMS communicated correctly with the dock, accepted a full charge without fault codes, and maintained stable voltage output across the motor draw cycle.
- Dock charging behaviour on this robot: Do not leave the Conga on its charging dock permanently. These robots trickle-charge when docked continuously, which accelerates capacity fade in the cell. Charge to full, then remove the robot from the dock until the next scheduled clean.
Suction dropping before the battery indicator reaches low
The Conga 4090 motor draws significantly more current when airflow is restricted — a partially blocked filter or full dustbin can push draw well above the rated operating current. When this happens, cell voltage sags under load before the indicator logic registers a low-battery state. The robot appears to lose suction mid-cycle with the indicator still showing charge. Clean the filter and empty the bin first; if the problem persists after fitting a fresh battery, the filter is still the cause, not the cell.
Motor cuts out and then recovers during a clean cycle
This is a BMS overcurrent trip, not a dead battery. When the Conga hits a carpet edge or a dust build-up causes sustained restricted suction, the motor current spikes. The BMS interprets this as an overcurrent event and cuts power to protect the cell. The robot pauses, the BMS resets within seconds, and it resumes — appearing to stutter or pause without warning. Check the brush roll for hair wrap and clean the filter; if the cutout stops after clearing the restriction, the cell and BMS are functioning as intended.