Hoover H-FREE 500 21.6V Replacement Battery 35602207

Hoover H-FREE 500 — 21.6V Li-ion Replacement Battery (35602207)

This 21.6V 3400mAh lithium-ion battery replaces the original pack in the Hoover H-FREE 500 cordless stick vacuum. It fits the H-FREE 500 series and matches the OEM voltage, capacity, and connector configuration. Part number 35602207 (also listed as B011) confirms the correct unit for this platform.

• H-FREE 500 platform fit: The H-FREE 500 uses a 21.6V cell architecture tied to a specific connector and BMS communication line. Substituting a mismatched pack — even at similar voltage — can cause the vacuum to refuse startup or report a fault. This battery matches the original handshake protocol so the motor controller recognises the pack on first insertion.
• Bench tested on actual hardware: We ran this cell through charge cycles and monitored the BMS cutoff thresholds under load. The protection circuit tripped correctly at overcurrent and recovered cleanly. Charge acceptance across cycles tracked within expected tolerance of the 3400mAh rating.
• Dock charging discipline on the H-FREE 500: The H-FREE 500 charging dock does not interrupt current once full — it continues pushing trickle charge into the cell. Leaving the vacuum docked between every use accelerates capacity fade. Charge to full, remove from the dock, and reconnect only when the battery is depleted.

Suction dropping before the battery indicator reaches low

The H-FREE 500 motor draws harder when airflow is restricted — a partially blocked filter or full dust container forces the motor to compensate, pulling more current than the BMS expects under normal load. The BMS reads this elevated draw as a low-voltage sag event and begins throttling motor speed before the battery indicator has visually updated. The result feels like battery failure but is often a maintenance issue. Clean or replace the filter, empty the bin, and recheck suction — motor draw should return to rated current and the sag will stop.

Motor cuts out mid-clean and restarts after a few seconds

This behaviour is an overcurrent trip — the BMS detects a current spike above its threshold, shuts the motor down to protect the cells, then resets once current drops. It happens most often when the vacuum hits a dense carpet pile or the brush roll snags debris, creating a momentary blockage that spikes resistance at the motor. The pack is not faulty — the protection circuit is doing its job. Clear the brush roll, check for blockages at the nozzle, and resume; if the cutout repeats on an unobstructed floor, verify the cell voltage reads at or above 21.6V off the charger before use.