Moulinex MX422901 Replacement Battery 4.8V 2000mAh

Moulinex MX422901 Series — 4.8V Ni-MH Replacement Battery (RS-AC3429)

This is a 4.8V, 2000mAh Ni-MH replacement battery for the Moulinex MX422901 cordless handheld vacuum cleaner. It also fits the MX444101, MX446101, and MX446101/2D1, along with several other models in the same family. Voltage and cell count match the original pack exactly.

• MX422901 family fit: These models share a common 4.8V six-cell Ni-MH architecture with the same connector pinout and physical pack dimensions. The BMS in each unit expects the same charge termination signal, so a correctly matched cell pack is what keeps the charger from cycling incorrectly.
• Bench tested on actual hardware: We ran this pack through the Moulinex charge cycle and monitored BMS termination. The charger reached cutoff cleanly and the motor drew consistent current through the full discharge curve without mid-cycle drop.
• Dock charging habit on Moulinex handhelds: Do not leave this vacuum on the charging dock permanently. Ni-MH cells in continuous trickle charge develop capacity fade noticeably faster than cells charged only when depleted. Charge to full, then remove from the dock.

Suction dropping before the battery indicator reaches low on the MX422901

Ni-MH cells under a restricted load — a clogged filter or partially blocked nozzle — sag in voltage before the indicator circuit registers a low-battery condition. The motor pulls more current to compensate for the restriction, which accelerates the voltage drop. The indicator reads pack state of charge, not motor load, so it lags behind what the motor is actually experiencing. Clear the filter first; if suction still drops early, the pack cells have likely developed uneven capacity across the string.

Motor cuts out briefly then recovers during use

This is a BMS overcurrent trip, not a power switch fault. When the nozzle encounters a blockage or the filter is heavily loaded, motor current spikes above the BMS threshold and the pack disconnects to protect the cells. The BMS resets after a short thermal delay, which is why suction returns. Check and clean the filter before assuming the battery is faulty — a clear airpath keeps motor draw within the BMS limit. If trips continue on a clean filter, the replacement pack resolves the issue by restoring full cell capacity and a stable current ceiling.