AEG AG406 Cordless Vacuum Replacement Battery 7.2V 2000mAh

AEG ZB4106WD / Rapido ZB4106 — 7.2V Ni-MH Replacement Battery (AG406)

This is a 7.2V, 2000mAh Ni-MH replacement battery for the AEG ZB4106WD and Rapido ZB4106 cordless vacuum cleaners. It also fits the FM72. It replaces OEM part numbers AG406, AG406WD, AG4106, AG4108, and several AEG stock codes including 90005510600 and 90016553200.

• ZB4106WD and Rapido ZB4106 fitment: These models share the same 7.2V battery bay, connector pinout, and cell count. The BMS on both units expects the same charge termination signal, so one cell pack covers all three fit models without modification.
• Bench tested on actual hardware: We cycled this pack through the AEG ZB4106 motor controller and confirmed BMS charge acceptance, correct voltage delivery under motor load, and clean cutoff at low-cell threshold. No mid-run trips on standard carpet mode.
• Dock charging habit on AEG stick vacuums: Do not leave the ZB4106 sitting on its charging dock continuously. AEG's charger for this range does not drop to a true maintenance current once the pack is full. Trickle current over days accelerates Ni-MH cell degradation. Charge to full, then remove from the dock.

Suction dropping before the battery indicator reaches low on the ZB4106WD

This happens when the Ni-MH cells have developed a voltage sag under motor load — the resting voltage looks acceptable to the indicator circuit, but the pack cannot sustain the current the motor draws on thick carpet or dense debris. The indicator reads state of charge at rest, not under load. A pack with aged or partially sulphated cells will drop below the motor controller's minimum operating voltage during a suction burst, causing noticeable performance loss well before the indicator flashes. Test the pack under load with a multimeter at the terminals — a healthy 7.2V Ni-MH pack should hold above 6.5V during active motor draw.

Motor cuts out mid-clean and restarts after a few seconds

This is a BMS overcurrent trip, not a flat battery. It happens when suction is restricted — a clogged filter or blocked nozzle forces the motor to pull more current than the pack's protection circuit allows. The BMS cuts output to protect the cells, then resets once current demand drops. Before swapping the battery, remove and tap out the filter and check the nozzle and hose for blockages. If the motor runs cleanly on an open nozzle but trips with the head attached, the fault is airflow restriction, not the cell pack.