Shark XFBT620 IX140 Replacement Battery 21.6V 2000mAh

Shark IX140 / IZ141 Series — 21.6V Li-ion Replacement Battery (XFBT620)

This is a 21.6V, 2000mAh (43.2Wh) lithium-ion battery pack for the Shark IX140, IX141, IZ141, UZ145, and related cordless stick vacuums. It replaces OEM part XFBT620 and fits directly into the original battery slot. Use it when the factory pack no longer holds a charge or shuts the vacuum off early.

• IX140 / IZ141 / UZ145 platform: These models share the same 21.6V cell architecture, connector format, and BMS communication protocol — which is why one pack covers the full range. Swapping between them requires no adapters.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the IX140 platform. The BMS handshaked correctly with the charger, accepted a full charge without fault codes, and held voltage under sustained motor load without tripping overcurrent cutoff.
• Dock charging habit on stick vacuums: Do not leave the vacuum sitting on the dock permanently. Continuous trickle charging on cordless vacuums accelerates capacity fade faster than normal cycle wear. Charge to full, then remove from the dock.

Suction dropping before the battery indicator reaches low

This happens when the motor draws more current than the BMS expects — usually caused by a partially blocked filter or brush roll restriction. The cell voltage sags under that elevated draw, and the BMS reads it as low charge even though capacity remains. The vacuum loses suction power noticeably while the LED still shows two bars. Clean the filter and clear the brush roll before assuming the battery is at fault — restored airflow drops current draw back into normal range and the voltage sag disappears.

Motor cuts out mid-clean then comes back on its own

This is a BMS overcurrent trip, not a dead battery. When suction is restricted — blocked filter, jammed brush roll, or heavy carpet pile — the motor strains and current spikes above the pack's rated threshold. The BMS shuts the output to protect the cells, then resets after a few seconds once current drops. Fix the restriction first: remove and tap out the filter, clear the brush roll, then restart the vacuum. If it trips immediately on clean carpet with no blockage, check that the battery terminals are seated fully and measure pack voltage — a healthy cell at rest should read at or above 22V.