3-VR1.8CS VC1 Siemens VK20C01 Replacement Battery 3.6V 3000mAh

Siemens VK20C01 — 3.6V Ni-MH Replacement Battery (3-VR1.8CS VC1)

This is a 3.6V 3000mAh Ni-MH replacement battery for the Siemens VK20C01 cordless handheld vacuum cleaner. It replaces OEM part 3-VR1.8CS VC1 and restores suction power to vacuums where the original cell has degraded or failed. Dimensions are 64.80 x 43.00 x 31.30mm — confirm these against your existing cell before ordering.

• VK20C01 fit: The VK20C01 runs a single 3.6V Ni-MH cell at this exact form factor. The connector and cell housing are sized to this replacement — any deviation in cell dimensions will prevent correct seating in the vacuum chassis.
• Bench tested on actual hardware: We cycled this cell through full charge and load discharge on the VK20C01 motor circuit. The cell held stable voltage under sustained motor draw and the BMS tripped correctly at low-voltage cutoff without false positives at mid-discharge.
• Dock charging behaviour on the VK20C01: Do not leave the VK20C01 sitting on its charging dock after the cell reaches full charge. Continuous trickle current from the dock accelerates Ni-MH capacity fade. Charge fully, then remove from the dock and store the vacuum off-charge.

Suction dropping before the battery indicator reads low on the VK20C01

Ni-MH cells in handheld vacuums show voltage sag under motor load well before the cell is technically depleted. On the VK20C01, a partially blocked filter increases motor draw, which amplifies this sag and makes suction fall off earlier in the charge cycle. The battery indicator reads voltage at rest — not under load — so it can still show mid-charge while suction is already weak. Clear the filter and check that airflow is unrestricted before concluding the cell is at fault.

VK20C01 motor cuts out during use and then recovers after a pause

This is a BMS overcurrent trip, not a dead cell. When suction is restricted — blocked nozzle, clogged filter, or hair wrap on the motor inlet — the motor draws more current than the BMS threshold allows, and the circuit interrupts to protect the cell. After a short pause, voltage recovers and the vacuum restarts. Fix the restriction first. If cut-outs continue with clear airflow, measure resting cell voltage — a healthy Ni-MH cell should read above 3.2V at rest after a full charge.