About this replacement
Leifheit PowerMax 11920 / 89022 / PowerMax Supra — 4.8V Ni-MH Replacement Battery (D-4/5SC1300 x 4)
This is a 4.8V, 2200mAh Ni-MH battery pack for the Leifheit PowerMax 11920, 89022, and PowerMax Supra cordless vacuum cleaners. It replaces the original pack when the vacuum loses charge capacity or fails to hold a charge. Capacity figure is sourced from the product specification — 2200mAh, 10.56Wh.
- PowerMax 11920, 89022, and Supra compatibility: All three models share the same 4.8V motor rail and cell format. The D-4/5SC1300 x 4 configuration matches the original sub-C cell arrangement, connector position, and BMS voltage thresholds across the range.
- Bench tested on actual hardware: We ran this pack through discharge cycles on the PowerMax platform. The BMS held cutoff correctly at low-cell voltage and the motor draw registered within the expected current band for both hard floor and carpet passes.
- Dock charging habit on the PowerMax series: The PowerMax charger does not switch to a true maintenance mode after full charge. Leaving the vacuum on the dock continuously passes a low-level trickle current that degrades Ni-MH cells faster than cycle use. Charge to full, then remove the vacuum from the dock.
Suction dropping before the battery indicator reaches low on the PowerMax
This happens when the motor draws more current than rated — usually because the filter is partially blocked. Under restricted airflow, the motor load increases, voltage sags across the cells, and the BMS reads that sag as a low-battery condition even when the pack still holds charge. The vacuum throttles back or cuts suction output as a result. Clean or replace the filter first, then retest — if suction holds consistently, the battery is not the root cause.
Motor cuts out mid-clean then recovers after a short pause
This is a BMS overcurrent trip, not a dead battery. When suction is restricted — by a blocked nozzle, full dust container, or clogged filter — the motor pulls sustained high current and the BMS shuts the output to protect the cells. After a brief rest the pack voltage recovers and the motor restarts. Clear the blockage, empty the container, and check the filter before assuming the battery has failed. If the trip repeats on a clear airpath, measure pack voltage under load — it should hold above 4.0V during motor run.