About this replacement
HOBOT Legee 668 / 669 — 14.8V Li-ion Replacement Battery (HB668P108)
This is a 14.8V, 2600mAh Li-ion replacement battery for the HOBOT Legee 668 and Legee 669 robot vacuum. It slots into the battery bay on either model and restores the cleaning system to full operating capacity. Capacity is rated at 38.48Wh, matching the original HB668P108 specification.
- Legee 668 and 669 compatibility: Both models share the same 14.8V battery platform, connector layout, and BMS handshake protocol. A single cell works across both units without modification.
- Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the Legee 668. The BMS negotiated correctly with the onboard charger, and the motor controller received consistent voltage throughout the draw cycle with no false low-battery cutoffs.
- Dock charging habit on the Legee 668: Do not leave the Legee 668 sitting on the dock permanently between uses. Continuous trickle charging accelerates capacity fade in Li-ion cells. Charge to full, then remove the unit from the dock until the next cleaning session.
Suction dropping before the battery indicator reaches low
The Legee 668 runs a brushroll and wet mopping pump simultaneously, which puts a sustained combined load on the cell. When the battery begins to age, internal resistance rises and voltage sags under that combined draw — even if the indicator still shows mid-charge. The motor controller interprets the voltage sag as insufficient power and reduces fan speed to compensate. Cleaning performance drops well before the battery indicator triggers the low warning.
Motor cuts out mid-cycle and then recovers after a few seconds
This is a BMS overcurrent trip, not a dead battery. It happens when the brushroll encounters a restriction — a tangled hair wrap, a clogged filter, or a rug edge — and current draw spikes above the BMS threshold. The BMS disconnects the load briefly, then resets and allows the motor to restart. Clean the brushroll and check the filter before blaming the cell. If trips continue on a clear brushroll with a new battery, verify the filter is fully seated and unblocked — restricted airflow forces the motor to draw above rated current even on an open floor.