About this replacement
Karcher WV5 / WV7 Series — 3.7V Li-ion Replacement Battery (4.633-083.0)
This 3.7V 2000mAh Li-ion cell replaces the original battery in the Karcher WV5, WV7, WV50, and WV 5 Window Vac series. These cordless handheld window vacuums use squeegee and suction to pull water and cleaning solution off glass surfaces. OEM part numbers 4.633-083.0, 2.633-123.0, and 9.013-675.0 all cross-reference to this cell.
- WV5 and WV7 platform fit: Karcher carried this same 3.7V single-cell Li-ion format across the WV5, WV7, and WV50 lines. The connector pinout, BMS handshake voltage, and cell dimensions — 80.30 × 55.10 × 28.40mm — are identical across those models, so one cell covers the full range.
- Bench tested on actual hardware: We cycled this cell on a WV5 unit and confirmed the BMS accepted the replacement without error. The motor spun to full speed, the suction head held consistent draw, and the charge circuit terminated cleanly at capacity.
- Dock charging on the WV5: The WV5 charges via a wall-mounted dock that has no auto-cutoff at the dock level — the BMS handles termination inside the unit. Remove the vacuum from the dock once the indicator shows full. Leaving it seated on the dock indefinitely feeds a trickle current that degrades cell capacity over repeated cycles.
Suction dropping before the battery indicator reaches low on the WV5
The WV5 motor draws harder when the squeegee channel or collection tank is partially blocked — restricted airflow raises current draw, which causes cell voltage to sag earlier than the indicator expects. The battery indicator on this unit reads state-of-charge under a light reference load, not under actual motor draw. So the indicator can still show two bars while the motor is already voltage-starved under restriction. Clear the squeegee blade channel and empty the tank first — if suction recovers immediately, the battery is fine and the restriction was the cause.
WV5 motor cuts out mid-wipe then recovers after a few seconds
This is a BMS overcurrent trip, not a flat battery. When the suction path is blocked — a clogged squeegee slot, a full tank, or a pinched nozzle — motor current spikes past the BMS threshold and the cell is disconnected as a protection response. The BMS resets after a short thermal wait, which is why the device restarts on its own. Check the nozzle, clear any debris from the suction slot, and empty the collection tank before the next pass. If the cut-out stops after clearing the blockage, the cell and BMS are working correctly.