Cecotec Conga 05439 Replacement Battery 14.8V 2600mAh

Cecotec Conga Immortal ExtremeSuction — 14.8V Li-ion Replacement Battery (CMICR18650-4S1P)

This is a 14.8V 2600mAh Li-ion battery pack for the Cecotec 05439 and Conga Immortal ExtremeSuction cordless stick vacuum. It uses four 18650 cells wired in a 4S1P configuration to match the voltage rail the motor controller expects. Capacity is 38.48Wh, matching the original specification.

• 05439 / Conga Immortal ExtremeSuction fit: Both model references share the same 14.8V motor platform, the same connector orientation, and the same BMS handshake protocol — which is why one battery covers both. The 4S1P cell arrangement delivers the sustained current the suction motor draws across carpet and hard floor transitions.
• Bench tested on actual hardware: We ran this pack through the Conga Immortal's charge cycle and confirmed the BMS accepted the charger handshake without fault codes. Cell balance across all four 18650s was within 20mV at full charge, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• Dock charging habit on the Conga Immortal: Do not leave this vacuum sitting on the charging dock between every use. Continuous trickle charge from permanent docking accelerates capacity fade on 4S Li-ion packs faster than normal cycle ageing. Charge to full, then remove it from the dock.

Suction dropping before the battery indicator reaches low

This happens when the motor draws more current than the pack can sustain under load — not because the cells are empty, but because internal resistance has risen enough to cause voltage sag. On a 14.8V 4S pack, even moderate resistance increase per cell compounds across all four in series. The motor controller reads the sagging voltage as low-battery and reduces power to protect the circuit. If your filter is partially blocked, the motor works harder, draws more amps, and triggers this sag earlier in the charge cycle. Clean the filter first — if suction still drops early, the pack needs replacing.

Motor cutting out mid-clean and recovering after a few seconds

This is a BMS overcurrent trip, not a motor fault. When airflow is restricted — blocked filter, full dust container, or a trapped obstruction in the brush head — the motor spins harder to maintain suction, pulling current past the BMS protection threshold. The BMS cuts the circuit, the motor stops, and after a few seconds the BMS resets and allows power again. Clear the obstruction or replace the filter, then confirm the battery voltage reads at least 16.0V on a full charge before ruling out a cell fault.