Gtech Multi MK2 21.6V Replacement Battery 1301A0002

Gtech Multi MK2 — 21.6V Li-ion Replacement Battery (1301A0002)

This 21.6V 2500mAh Li-ion battery replaces the original pack in the Gtech Multi MK2 and Multi MK2 K9 cordless vacuum cleaners. It also fits the ATF011 and Power Floor MK1 platforms. When the original cell loses hold, suction drops early — this pack restores full motor voltage across the cleaning cycle.

• Multi MK2 and K9 platform fit: These models run the same 21.6V architecture with a shared connector footprint and BMS handshake. The K9 variant draws slightly harder through pet hair attachments, but the voltage rail and charge protocol are identical across the range.
• Bench tested on actual hardware: We ran the pack through full charge and discharge cycles on the Multi MK2 dock. The BMS handled cutoff cleanly at low voltage and accepted the charger handshake without fault codes or charge refusal on the first connection.
• Dock charging discipline for the Multi MK2: Do not leave this vacuum sitting on the dock continuously. Gtech cordless vacuums develop capacity fade noticeably faster under constant trickle charge. Charge to full, remove from the dock, and return it only when depleted.

Why the Multi MK2 loses suction before the battery indicator hits low

The battery indicator on the Multi MK2 reads cell voltage, not available capacity. As a Li-ion pack ages, internal resistance climbs. Under motor load, voltage sags below what the BMS needs to sustain full motor speed — even while the indicator still shows charge remaining. A new pack with low internal resistance holds voltage steady under load, so the motor gets consistent power from the first pass to the last.

Motor cuts out mid-clean then recovers after a few seconds

This is a BMS overcurrent trip, not a dead battery. When airflow is restricted — blocked filter, packed brush roll, or a sealed nozzle — the motor works harder and draws current above the BMS cutoff threshold. The BMS shuts down to protect the cells, then resets once current drops. Clean or replace the filter first. If the cut-out stops, the battery was not the problem. If it continues with a clear filter, check the brush roll for hair wrap before drawing any conclusion about the cell.