Hoover SU180 Replacement Battery 18V 2000mAh

Hoover SU180 Series — 18V Ni-MH Replacement Battery (49005889)

This is an 18V, 2000mAh Ni-MH replacement battery pack for the Hoover SU180 cordless stick vacuum. It fits the SU180, SU180B8, SU180T2, and SU180WT models. The pack slots into the same housing position as the original and connects to the same motor drive circuit.

• SU180 model family fit: All listed SU180 variants run the same 18V motor rail and use the same battery housing and connector orientation. One pack covers the full range — no wiring or adapter changes needed.
• Bench tested on actual hardware: We cycled this pack through repeated load tests against the SU180 motor circuit. The BMS held voltage steadily under sustained suction load and cut off cleanly when cells reached the lower discharge threshold.
• Dock charging habit on the SU180: The SU180 charging dock does not stop delivering current when the pack is full. Leaving the vacuum docked permanently causes trickle charge heat buildup in the Ni-MH cells. Charge to full, then remove from the dock.

Cordless vacuum losing suction before the battery indicator reaches low

On the SU180, suction loss under a full charge usually points to voltage sag at the motor rather than actual cell depletion. When the filter is partially blocked, the motor draws more current than rated to maintain airflow. This extra draw pulls cell voltage down faster than the indicator circuit expects, so the motor underperforms while the display still shows charge remaining. Clean or replace the filter first — if suction recovers immediately, the cells are fine.

Motor cutting out mid-clean and recovering after a short pause

This is a BMS overcurrent trip, not a dead battery. When the SU180 runs over heavy carpet or a restricted floor surface, suction resistance spikes and the motor pulls current above the BMS threshold. The BMS disconnects to protect the cells, which is why the motor stops and then restarts after 15–30 seconds once current demand drops. Clear any blockage in the nozzle or hose, clean the filter, and retest. If the cutout stops occurring, the fault was restriction-driven, not cell failure.