Gtech Multi K9 22V Replacement Battery 2000mAh 102A0008

Gtech Multi K9 / AFT001 — 22V Li-ion Replacement Battery (102A0008)

This is a 22V, 2000mAh (44Wh) Li-ion replacement battery for the Gtech Multi K9 and AFT001 cordless vacuum. It slots into the battery bay using the same connector and latch as the original 102A0008 cell. When the stock battery won't hold charge long enough to finish a clean, this is the direct swap.

• Multi K9 and AFT001 compatibility: Both models share the same 22V power rail, battery bay dimensions, and BMS handshake protocol. One cell fits either unit without adapters or modifications.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Multi K9 platform. The BMS communicated correctly with the vacuum's charge circuit and the protection cutoffs triggered at the expected voltage thresholds under load.
• Dock charging habit on the Multi K9: Do not leave the vacuum sitting on the charging dock between uses. The Multi K9 dock does not cut trickle current once the cell reaches full charge, so continuous docking accelerates capacity fade. Charge to full, then remove from the dock.

Suction dropping before the battery indicator reaches low

The Multi K9 motor draws higher current the moment airflow is restricted — a partially blocked filter or full dust cup forces the motor to work harder to maintain suction. That elevated draw causes voltage to sag at the cell before the indicator logic registers a low state, so the vacuum feels weak while the LED still shows charge remaining. The BMS reads cell voltage under load, not resting voltage, which is why the indicator lags behind real performance. Clear the filter and empty the cup first — if suction recovers, the battery is not the cause.

Motor cuts out mid-clean then restarts after a short pause

This is a BMS overcurrent trip, not a flat battery. When the motor sustains a high-draw state — usually from a blocked filter or a hair wrap on the brush bar — current spikes past the BMS protection threshold and the cell disconnects to prevent damage. After a few seconds the BMS resets, power returns, and the cycle repeats if the restriction is still there. Remove the brush bar, check for blockages in the inlet, and clean the filter before assuming the battery is at fault. A healthy replacement cell will trip the same way under the same conditions.