About this replacement
Hoover 39400224 / CATV18LS003 Series — 18V Li-ion Replacement Battery (48009782)
This 18V 2500mAh (45Wh) Li-ion battery replaces OEM part 48009782 in Hoover cordless stick vacuums. It fits the 39400224, CATV18LS003, 39400207, and ATN18LI011 among other models in this range. When the original cell loses capacity or stops holding charge, this replacement restores full cordless operation.
- Cross-model fit — 39400224 and CATV18LS003 series: These Hoover stick vac models share the same 18V battery bay, connector pinout, and BMS handshake protocol. One replacement cell covers the full range without adapters or modifications.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Hoover stick vac platform. The BMS engaged correctly at low-voltage cutoff, and the charger handshake completed without error codes on first connection.
- Dock charging discipline — critical for this platform: Do not leave this vacuum on the charging dock permanently. Hoover cordless stick vacs on continuous dock charge develop capacity fade significantly faster than units charged only when depleted. Charge to full, then remove from the dock.
Cordless vacuum losing suction before the battery indicator reaches low
This happens when the motor draws more current than the BMS allows under sustained load — usually caused by a partially blocked filter or bin, not a failing battery. The motor has to work harder against restricted airflow, pulling current above the BMS trip threshold before the cell voltage actually drops. The BMS interprets this as an overcurrent condition and throttles output. Clean the filter and empty the bin first, then retest — most users find suction returns to full strength at the same charge level.
Motor cuts out mid-clean then recovers after a short pause
This is a BMS overcurrent trip, not a dead battery. On sustained restricted suction — carpet pile, blocked nozzle, full bin — the motor draws a spike above the BMS protection threshold and the cell disconnects briefly to protect the pack. After a few seconds the BMS resets and power returns. The fix is to clear the restriction at the nozzle or filter before resuming. If cutouts continue on an unblocked machine, check cell voltage under load — a healthy pack should hold above 15V during normal motor operation.