About this replacement
BobSweep WVP58021 / Bob PetHair Series — 14.4V Li-ion Replacement Battery (UR18650ZY-4S1P-AAM)
This is a 14.4V, 2600mAh (37.44Wh) Li-ion battery for the BobSweep WVP58021 robotic vacuum. It also fits the Bob PetHair Slam, Bob PetHair Vision, and Bob PetHair Vision Plus. When the original cell degrades and the robot stops completing a cleaning cycle, this is the direct swap.
- WVP58021 and Bob PetHair platform compatibility: These models share the same 14.4V rail, connector pinout, and BMS handshake protocol. Swapping between them carries no electrical risk — the pack talks to each dock and mainboard the same way.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the WVP58021 mainboard. The BMS responded correctly to low-voltage cutoff and overcurrent conditions without tripping prematurely under normal suction motor load.
- Dock charging behaviour on BobSweep robots: Remove the robot from the dock once the charge indicator shows full. BobSweep units left on the dock indefinitely receive a continuous trickle that accelerates capacity fade in Li-ion cells. Charge only when depleted, then undock.
Suction dropping before the battery indicator reaches low
This happens when the suction motor draws more current than rated — usually because the filter is partially blocked. The BMS reads the elevated draw as a potential overcurrent event and reduces power delivery to protect the cell. The robot still runs, but suction output drops noticeably. Clean or replace the filter first; if suction recovers immediately, the battery was never the fault.
Motor cutting out mid-cycle and then recovering
A sustained blockage — matted pet hair, a clogged brush roll, or a restricted exhaust — forces the motor to spike well above its steady-state current draw. The BMS trips on overcurrent to protect the pack and cuts power. Once the spike clears, the BMS resets and the motor restarts. Clear the brush roll and check the exhaust vent; if the fault stops, the BMS is working correctly. If the cutout continues on a clean robot, measure pack voltage at rest — a fully charged cell should read at or above 16.4V.