HOBOT Legee 668 Replacement Battery 14.4V 2600mAh

HOBOT Legee 668 / Legee 669 — 14.4V Li-ion Replacement Battery

This 14.4V 2600mAh (37.44Wh) Li-ion battery fits the HOBOT Legee 668 and Legee 669 robotic vacuum cleaners. It replaces the original pack when capacity has faded and the unit can no longer complete a full cleaning cycle. Dimensions are 69.40 × 37.00 × 37.00mm — verify against your existing pack before fitting.

• Legee 668 and 669 compatibility: Both models run the same 14.4V power rail and use the same connector and BMS handshake, which is why one pack covers both. The BMS communicates state-of-charge to the dock — a mismatched cell won't report correctly and the unit will refuse to leave the dock.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the bench and monitored the BMS response at the dock interface. The handshake completed correctly, the unit accepted the charge signal, and the BMS cutoff triggered at the expected low-cell threshold.
• Dock charging habit for this vacuum: Do not leave the Legee on the charging dock permanently between uses. These robotic vacuums on continuous dock charge develop capacity fade significantly faster than units charged only when depleted. Charge to full, then remove from the dock.

Suction dropping before the battery indicator reaches low

On the Legee 668 and 669, the suction motor is the single largest draw on the 14.4V rail. When the filter is partially blocked, the motor works harder, pulling more current than the BMS's sustained-draw threshold. Voltage on the cells sags under that load even though the pack still has charge remaining. The unit reads this sag as low battery and throttles the motor — or stops — well before the indicator shows empty. Clean the filter first. If suction recovers immediately, the pack is fine; the filter was the cause.

Motor cutting out mid-cycle and then recovering after a pause

This is a BMS overcurrent trip, not a dead battery. A sustained blockage — hair wrap around the brush roll, a stuck debris clump — forces the motor to draw above its rated current. The BMS cuts power to protect the cells. After a short pause the BMS resets and the unit runs again, often repeating the cycle. Clear the brush roll and check the suction path for obstructions. If the trip stops occurring after clearing the blockage, the battery and BMS are functioning correctly — no replacement needed.