About this replacement
Gtech SW01 / SW02 / SW04 Series — 7.2V Ni-MH Replacement Battery (HSC5/7.2)
This is a 7.2V 1800mAh Ni-MH replacement battery for the Gtech SW01, SW02, SW04, and SW20 cordless stick vacuums. It replaces OEM part numbers HSC5/7.2, AS-193CRN, 2-01-033, AS-193E9B, and SW04-NB. The battery slots into the same housing position as the factory cell and connects to the same charge circuit.
- SW01 / SW02 / SW04 / SW20 platform: These models share the same 7.2V cell format, connector pinout, and charge circuit. One battery fits across the range because Gtech kept the power pack architecture consistent through these generations.
- Bench tested on actual hardware: We ran this cell through the SW-series charge circuit and monitored the BMS handshake. The charge cycle completed without fault codes, and the cell held 7.2V at rest under no-load conditions after a full charge.
- Dock charging habit on Gtech stick vacs: Do not leave the SW01 sitting on the charging dock permanently. Continuous trickle charge accelerates capacity fade in Ni-MH cells faster than in lithium chemistry. Charge the battery fully, then remove it from the dock until the next use.
Suction dropping before the battery indicator reaches low on the SW01
This happens when the motor draws more current than the cell can sustain under load — not when the cell is actually flat. A partially blocked filter forces the motor to work harder, pulling current above the rated draw and causing voltage to sag early. The battery reads as partially charged because it is, but the motor can't get the amps it needs at that voltage. Clean or replace the filter first, then retest suction across the full charge cycle.
Motor cutting out mid-clean and then recovering after a few seconds
This is a BMS overcurrent trip, not a dead battery. When suction is restricted — blocked nozzle, clogged filter, or hair wrapped around the brush roll — the motor strains against the restriction and draws a spike of current the BMS interprets as a fault. The BMS cuts power to protect the cell, then resets once the current spike clears. Clear the blockage and check the filter before assuming the battery is at fault. If the cut-out persists on a clean, unobstructed vacuum, measure resting voltage — it should sit at or above 7.2V after a full charge.