About this replacement
Karcher VC 4 Cordless myHome — 25.2V Li-ion Replacement Battery (9.754-766.0)
This 25.2V Li-ion battery at 2000mAh (50.4Wh) replaces the original pack in the Karcher VC 4 Cordless myHome and VC 4 Cordless Premium myHome vacuum cleaners. It uses the same cell configuration and connector as the factory pack. Swap it in when suction power drops or the original no longer holds a useful charge.
- VC 4 Cordless myHome and Premium myHome compatibility: Both models run the same 25.2V six-cell architecture with an identical battery bay and BMS handshake. One battery covers either variant without modification.
- Bench tested on actual hardware: We cycled this pack on the VC 4 Cordless myHome under full suction load. The BMS held steady through the motor-start inrush current and maintained a clean cutoff at the low-cell threshold without false trips.
- Dock charging on the VC 4 Cordless: Do not leave the vacuum sitting on the charging dock indefinitely. The VC 4 Cordless does not actively manage trickle current the way high-end packs do — continuous dock time accelerates capacity fade. Charge to full, then remove it.
Suction dropping before the battery indicator reaches low
When the filter is partially blocked, the motor works harder to pull the same airflow. That extra draw increases current and causes the battery voltage to sag earlier than the indicator expects. The vacuum feels like it's losing power, but the battery gauge still reads mid-range. Clean or replace the filter first — if suction recovers, the battery is not the fault. If voltage still sags under load with a clean filter, the cell capacity has degraded and a replacement pack is the fix.
Motor cutting out briefly then recovering during use
This is a BMS overcurrent trip, not a motor fault. It happens when sustained restricted airflow — usually a clogged filter or blocked nozzle — forces the motor to pull more current than the BMS allows. The BMS interrupts the circuit, the vacuum stops, and then restores power once the overcurrent condition clears. Check the filter and clear any blockage at the nozzle before assuming the battery is faulty. If the cutout persists on a clear filter and clean airways, verify cell voltage under load is holding above 21V.