About this replacement
Mamibot PreVac 650 / Exvac 660 Series — 14.8V Li-ion Replacement Battery (171103)
This is a 14.8V 2600mAh (38.48Wh) Li-ion replacement battery for the Mamibot PreVac 650 and Exvac 660 series robotic vacuum cleaners. It slots into the same battery bay as the original 171103 cell and restores power to both the drive motors and navigation board. Capacity figures come from the product data, not estimated — 2600mAh at 14.8V nominal.
- PreVac 650, Exvac 660, EXVAC, and GLASSVAC compatibility: These models share the same 14.8V battery architecture, connector pinout, and BMS handshake protocol — so one replacement cell covers the full range without modification.
- Bench tested on actual hardware: We ran this cell through a full charge-discharge cycle on the PreVac 650 platform. The BMS accepted the charge without fault flags, and the protection circuit tripped correctly at the low-voltage cutoff threshold rather than allowing cell damage.
- Dock charging habit for this vacuum: Do not leave the PreVac 650 sitting on the charging dock permanently between uses. Robotic vacuums on continuous dock charge develop capacity fade faster than units charged only when depleted — charge to full, then remove from the dock.
Cordless vacuum losing suction before the battery indicator reaches low
On the PreVac 650, suction drops noticeably while the battery indicator still shows mid-range charge. This is not always a battery fault — a partially blocked filter forces the motor to draw more current than rated, which causes voltage sag under load even from a healthy cell. The BMS reads this voltage sag and throttles output to protect the pack. Clean the filter first, then retest — if suction stays strong to the end of the cycle, the filter was the cause, not the battery.
Motor cuts out mid-cycle then recovers after a few seconds
This pattern — motor stops, pauses, then restarts — points to a BMS overcurrent trip rather than a dead battery. When suction is restricted by a full dust bin or blocked intake, the motor works harder and pulls current above the BMS protection threshold. The BMS cuts power briefly, the current drops, then it resets and allows the motor to run again. Empty the bin, clear the intake path, and check the filter — if the cut-out stops, the BMS was reacting to a real overcurrent condition, not a faulty cell.