Cecotec 05539 Replacement Battery 18.5V 2600mAh Li-ion

Cecotec Conga Popstar Micro 18.5V — 18.5V Li-ion Replacement Battery (CMICR18650-5S1P)

This 18.5V 2600mAh (48.1Wh) Li-ion battery pack replaces the original cell in the Cecotec 05539 and Conga Popstar Micro 18.5V cordless stick vacuums. It uses the same 5S1P 18650 cell configuration as the factory pack. Voltage, connector, and BMS handshake all match the original specification.

• Conga Popstar Micro 18.5V platform: The 05539 and Conga Popstar Micro share the same 18.5V nominal rail, 5S cell arrangement, and dock-side charging circuit. Any pack that matches this configuration will communicate correctly with the onboard BMS without triggering a charge fault.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the Conga Popstar Micro platform. The BMS accepted full charge without error, held voltage through motor start, and maintained consistent output across multiple cleaning runs on both hard floor and carpet modes.
• Dock charging habit on the Conga Popstar Micro: Do not leave this vacuum on the charging dock continuously between uses. The Conga Popstar Micro dock does not interrupt charge once full — sustained trickle current accelerates cell degradation faster than normal cycle wear. Charge to full, then remove from dock.

Suction dropping before the battery indicator reaches low

The 05539 motor draws significantly more current when the filter is partially blocked — sometimes two to three times the rated draw under restriction. This extra load pulls pack voltage down faster than the indicator circuit expects, so suction fades while the LED still shows adequate charge. The BMS interprets the voltage sag as a low-cell event and begins throttling output to protect the cells. Clean or replace the filter first — if suction restores to full power, the battery is not the fault.

Motor cutting out briefly then recovering during use

This is a BMS overcurrent trip, not a faulty battery. It happens when sustained airflow restriction forces the motor to pull beyond the pack's continuous current rating — the BMS opens the discharge circuit, the motor stops, the pack resets in seconds, and power returns. A clean filter is the fix in most cases. If the cutout continues after cleaning the filter, check for a blockage in the nozzle or hose before replacing the battery. Confirm pack voltage sits above 17V at rest after the trip — anything below that points to genuine cell wear rather than a BMS protection event.