About this replacement
Karcher FC 5 Cordless — 25.2V Li-ion Replacement Battery (0320-015217)
This 25.2V 2400mAh Li-ion battery replaces the original pack in the Karcher FC 5 Cordless, Basic FC 5 Cordless, and 1.055-601.0 floor cleaner. It matches the original voltage rail and connector layout. Capacity is rated at 60.48Wh — identical to the factory specification.
- FC 5 Cordless platform compatibility: The FC 5 Cordless and Basic FC 5 Cordless share the same 25.2V battery bay, connector pinout, and BMS handshake protocol. One pack fits both variants without modification.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on FC 5 Cordless hardware. The BMS responded correctly to the charger handshake, accepted a full charge without fault codes, and held voltage through simulated floor-cleaning loads.
- Dock charging habit on the FC 5 Cordless: The FC 5 Cordless charges fast — typically under two hours. Leaving it on the dock continuously after full charge pushes trickle current through the cells and accelerates capacity fade. Charge to full, then remove it from the dock.
Suction dropping before the battery indicator reaches low
On the FC 5 Cordless, suction loss mid-clean is rarely the battery's fault first. A partially blocked filter forces the motor to draw above its rated current, and voltage sags under that load even when the pack is near full charge. The BMS reads the sag as low battery and throttles output. Clean or replace the filter before swapping the pack — if suction restores, the battery was not the root cause.
Motor cutting out and self-recovering during use
If the FC 5 Cordless cuts out for two to three seconds then restarts on its own, the BMS is tripping on an overcurrent event — not a dead cell. This happens most often when suction is restricted: blocked filter, clogged roller, or debris stuck at the intake. The BMS protects the motor by cutting power momentarily, then resets once current drops. Clear the restriction and the cutouts stop; if they continue on a clean machine, verify the charger output voltage sits at 29.4V before attributing fault to the battery.