Cecotec Conga 5290 14.4V Replacement Battery 86371 5200mAh

Cecotec Conga 5290 / 8290 / 12090 Series — 14.4V Li-ion Replacement Battery (86371)

This 14.4V 5200mAh Li-ion battery fits the Cecotec Conga 5290, 8290, 12090, and 12090 Twice Roller Home&Fill robotic vacuum cleaners. It replaces OEM part numbers 86371, 88560, and 91049. Capacity is 74.88Wh — consistent with the original cell specification.

• Conga 5290 to 12090 platform compatibility: These four models share the same 14.4V battery rail, connector housing, and BMS handshake protocol. The vacuum's main board expects a specific cell communication response on power-up — this battery meets that requirement across all four variants.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Conga unit. The BMS engaged overcurrent protection correctly under simulated motor-load spikes and released cleanly when current normalised. Charge acceptance reached full capacity without cutoff errors.
• Dock charging behaviour on the Conga platform: The Conga charges via a contact dock that does not cut power when the cell reaches full capacity. Leaving the vacuum on the dock continuously accelerates capacity fade in Li-ion cells. Charge to full, then remove from the dock until the next cleaning cycle.

Suction dropping before the battery indicator reaches low on Conga models

This happens when the motor draws more current than the BMS threshold allows — usually caused by a partially blocked filter or brush roll, not a weak battery. The BMS reads the elevated current draw as a potential fault and reduces output to protect the cell. Clean the filter and check the brush roll for hair wrap before assuming the battery is at fault. If suction recovers immediately after cleaning, the battery was not the cause.

Conga powers on but motor cuts out mid-clean and then recovers

This is a BMS overcurrent trip — the motor briefly pulls above the safe current ceiling, the BMS disconnects, and then reconnects once current drops. It happens most often on thick carpet or when the suction path is restricted. The battery itself is not faulty; the BMS is doing its job. Clear the filter and check the intake path, then confirm the battery resting voltage reads above 13.0V before ruling out a cell issue.