Eureka FC9 22.2V Replacement Battery BP22240A 4000mAh

Eureka FC9 — 22.2V Li-ion Replacement Battery (BP22240A)

This is a 22.2V, 4000mAh Li-ion battery for the Eureka FC9 cordless vacuum cleaner. It replaces OEM part BP22240A when the original cell has lost charging capacity or no longer holds a useful charge. Swap it in to restore full motor voltage to the FC9's suction system.

• FC9 motor voltage rail: The FC9 runs its brushless motor directly off the 22.2V cell pack. Drop below that nominal voltage mid-clean and suction falls noticeably — especially on carpet where motor load spikes. This cell matches the OEM voltage rail exactly, so the motor controller sees no deviation from its expected input range.
• Bench tested on actual hardware: We cycled this cell on the FC9 platform and confirmed the BMS handshakes correctly with the vacuum's charge circuit. The protection board trips as expected on overcurrent and resets cleanly without requiring a manual reset procedure.
• Dock charging on the FC9: Do not leave the FC9 sitting on the charging dock continuously between uses. Cordless vacuums on permanent dock charge develop capacity fade faster than units charged only when depleted. Charge to full, then remove from the dock.

Suction dropping before the battery indicator reaches low on the FC9

This happens when the motor draws more current than the cell can sustain at mid-charge, causing voltage to sag under load even though the indicator still reads sufficient charge. On the FC9, a partially blocked filter forces the motor to work harder, pulling current above its normal operating draw. That extra draw accelerates voltage sag on an aging or cold cell. Clean or replace the filter first — if sag persists with a clean filter, the cell is the cause and the pack voltage at load will measure below 20V.

FC9 motor cuts out briefly then recovers during use

This is a BMS overcurrent trip, not a motor fault. When suction is restricted — by a blocked filter, a tangled brush roll, or a clogged hose — the motor strains and current spikes past the BMS protection threshold. The BMS cuts power for a second or two, then resets automatically once current drops. Clear the restriction completely, then confirm the brush roll spins freely by hand before running the vacuum again.