Ecovacs AZ1 Replacement Battery 18V 6700mAh Li-ion

Ecovacs AZ1 / Airbot Z1 — 18V Li-ion Replacement Battery (201-2109-0675)

This 18V 6700mAh Li-ion battery fits the Ecovacs DEEBOT AZ1 and Airbot Z1 robotic vacuum cleaners. It replaces OEM part numbers 201-2109-0675 and S18-Li-180-5200. Capacity is rated at 120.6Wh, matching the original power specification for these units.

• AZ1 and Airbot Z1 platform fit: Both models share the same 18V power rail, battery connector, and BMS handshake protocol. A single cell swap covers either unit without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the AZ1 platform. The BMS communicated correctly with the dock charger, accepted a full charge cycle, and released current to the drive motor and suction fan without fault codes or cutoff events.
• Dock charging practice for robotic vacuums: Do not leave the AZ1 sitting on its dock continuously between uses. Robotic vacuums on permanent dock connection receive a trickle charge that accelerates capacity fade in Li-ion cells. Charge to full, then remove from the dock until the next scheduled clean.

Suction dropping before the battery indicator reaches low on the AZ1

This happens when a partially blocked filter forces the suction motor to draw more current than rated, causing voltage sag in the cell before the state-of-charge display reflects depletion. The BMS sees sustained overcurrent and reduces output to protect the cell — suction drops noticeably while the indicator still shows adequate charge. The fix is not a new battery: clean or replace the filter first, then retest. If suction holds after a clean filter, the cell is not the cause.

AZ1 motor cuts out mid-clean and then recovers after a short pause

This is a BMS overcurrent trip, not a dead battery. It occurs when the suction path is restricted — a jammed brush roll, compacted filter, or blocked inlet — causing the motor to spike above the BMS current threshold. The BMS cuts power, the cell cools slightly, and the unit restarts. Clear the brush roll and inlet, then check filter restriction. If the cutout stops after clearing the blockage, the cell and BMS are functioning as intended.