Water Tech Pool Blaster Max 8.4V Ni-MH Replacement Battery

Water Tech Pool Blaster Max — 8.4V Ni-MH Replacement Battery

This is an 8.4V 3000mAh Ni-MH replacement battery for the Water Tech Pool Blaster Max cordless pool vacuum. It fits directly into the handheld unit used to suction leaves, dirt, and sediment from pool floors and walls. Replace it when the original cell loses capacity or stops holding a charge.

• Pool Blaster Max compatibility: The Pool Blaster Max runs a brushed DC motor on an 8.4V Ni-MH cell stack. This replacement matches that voltage rail and cell count. The battery bay accepts this pack's 88.10 x 89.90 x 22.70mm footprint without modification.
• Bench tested on actual hardware: We ran this battery through full charge and discharge cycles on the Pool Blaster Max motor load. The cell stack maintained voltage above the cutoff threshold throughout sustained suction draws, and the protection circuit responded correctly to a simulated blockage event.
• Dock charging on the Pool Blaster Max: Do not leave the Pool Blaster Max sitting on its charge cradle continuously between uses. Ni-MH cells in this unit develop capacity fade faster under trickle charge than under normal cycle use. Charge to full, then remove the unit from the dock.

Suction dropping before the battery indicator reaches low

Ni-MH cells show a flatter discharge curve than lithium chemistries, so the battery indicator can still read mid-range while the cell voltage has already sagged under motor load. On the Pool Blaster Max, a partially blocked filter increases the motor's current draw significantly, accelerating that voltage sag. The motor slows before the indicator responds, which users notice as a drop in suction strength. Clear the filter basket first — if suction recovers immediately, the cell is fine and the filter was the cause.

Motor cuts out mid-clean and then restarts after a short pause

This is a protection circuit trip, not a dead battery. When the Pool Blaster Max draws sustained high current — typically from a blocked intake or a clogged filter mesh — the battery's overcurrent protection interrupts the circuit to prevent cell damage. Removing the load (lifting the unit out of the water or clearing the debris path) allows the protection circuit to reset. Check and rinse the filter after every session; a filter carrying fine sediment buildup restricts flow enough to trigger this trip even on a fully charged cell.