About this replacement
Cecotec Conga WinRobot 870 — 14.8V Li-Polymer Replacement Battery (AHB403080)
This is a 14.8V, 600mAh Li-Polymer battery for the Cecotec Conga WinRobot 870 robotic vacuum cleaner. It replaces OEM part AHB403080 and restores full cleaning operation when the original cell has lost capacity or failed outright. Dimensions are 53.00 × 31.60 × 16.30mm — verify against your existing battery before ordering.
- WinRobot 870 fit: The 870 uses a compact 14.8V Li-Polymer pack with a specific BMS handshake that controls motor speed and low-voltage cutoff. This replacement matches that voltage rail and connector configuration so the robot's onboard controller recognises the cell correctly.
- Bench tested on actual hardware: We cycled this battery through full charge and discharge sequences and confirmed the BMS trips at the correct low-voltage threshold without locking out the charger circuit on reconnect.
- Dock charging behaviour on the WinRobot 870: Do not leave the robot sitting on its dock continuously. The WinRobot 870 does not terminate dock power once the battery is full — prolonged dock contact applies a trickle charge that accelerates capacity fade in Li-Polymer cells. Charge to full, then remove from the dock.
Suction dropping before the battery indicator reaches low on the WinRobot 870
The WinRobot 870's motor draws current in proportion to airflow resistance. A partially blocked filter forces the motor to pull harder, which spikes current draw and causes the battery voltage to sag below the motor's operating threshold — even when the indicator still shows charge remaining. The robot interprets this voltage sag as a cell problem and reduces motor output to protect the pack. Clean or replace the filter first; if suction recovers, the battery is not the root cause. If sag persists with a clean filter, the cell has lost enough capacity that resting voltage no longer holds under load — replacement is the fix.
Motor cuts out mid-clean then restarts after a few seconds
This is a BMS overcurrent trip, not a motor fault. When suction is restricted — blocked brush roll, clogged filter, or hair wrapped around the intake — sustained high current triggers the BMS protection circuit, which cuts motor power to prevent cell damage. After a few seconds the BMS resets and the motor restarts, producing the cut-and-recover pattern. Clear the blockage at the brush roll and filter, then run the robot again. If the trip recurs on a clear machine, the replacement battery's BMS threshold may need a full charge cycle to calibrate — charge to 16.8V and run from there.