About this replacement
Philips PowerPro Aqua FC6400 Series — 14.8V Li-ion Replacement Battery (4ICR19/65)
This 14.8V 3400mAh Li-ion battery pack replaces the original 4ICR19/65 cell in the Philips PowerPro Aqua FC6400 cordless vacuum. It fits the FC6400, FC6400/01, FC6401/01, and related variants in the FC6400 series. The pack restores suction power to the wet and dry handheld vacuum after the original cell has degraded.
- FC6400 series compatibility: The FC6400 and FC6401 variants share the same 14.8V battery rail, connector pinout, and BMS handshake protocol. One pack covers the full series without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on an FC6400 unit. The BMS negotiated correctly with the Philips charger, accepted a full charge cycle, and released current without tripping overcurrent protection under standard carpet-mode motor load.
- Dock charging behaviour on the FC6400: The FC6400 charging dock does not cut power automatically when the pack reaches full charge. Leaving the vacuum docked continuously forces a trickle charge through the cells. Charge to full, then remove the vacuum from the dock until the next use.
Suction dropping before the battery indicator reaches low
This happens when the motor draws more current than the rated load — typically caused by a partially blocked filter or debris restriction, not actual cell depletion. The BMS reads the elevated current draw as a voltage sag event and begins throttling output to protect the cells. Clean the filter and check the dirt container before assuming the battery is at fault. A healthy cell at this capacity should hold steady voltage above 13.8V under normal motor load.
Motor cutting out mid-clean and then recovering after a pause
This is a BMS overcurrent trip, not a failed battery. When suction is restricted — by a clogged filter or blocked nozzle — the motor spins harder and pulls current above the BMS cutoff threshold. The BMS disconnects the circuit, which reads as a sudden power cut. After a short pause, cell voltage recovers and the vacuum starts again. Check and clean the filter first. If the cut-out continues on an unblocked, clean filter, check that the replacement pack's BMS cutoff rating matches the FC6400's motor draw spec before assuming a defective cell.