Eureka i5 Cordless Vacuum Replacement Battery 14.8V 3400mAh

Eureka i5 — 14.8V Li-ion Replacement Battery

This is a 14.8V, 3400mAh lithium-ion battery pack for the Eureka i5 cordless stick vacuum. It replaces the original cell when capacity has degraded from repeated charge cycles. Swapping the battery restores full suction power without replacing the entire unit.

• Eureka i5 fitment: The i5 uses a specific battery rail and connector housing tied to this 14.8V four-cell Li-ion configuration. The BMS inside this pack matches the charge profile the i5's charging circuit expects — voltage draw, cutoff threshold, and cell arrangement all correspond to the original specification.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on the i5 platform. The BMS engaged correctly at low-cell threshold and the charger handshake completed without fault codes. Suction power held steady from full charge down through normal depletion.
• Dock charging discipline: Do not leave the i5 on the charging dock continuously. Trickle charge from permanent dock contact accelerates capacity loss in Li-ion cells faster than normal cycle wear. Charge to full, then remove the vacuum from the dock until the next use.

Suction dropping before the battery indicator reaches low

This happens when a partially blocked filter forces the motor to draw more current than its rated load. The BMS sees an elevated draw and begins throttling output voltage to protect the cells — suction weakens even though the indicator still shows charge remaining. The battery itself is not always at fault here. Remove and clean the filter first, then retest. If suction holds steady after cleaning, the cell is fine.

Motor cutting out briefly then recovering during use

This is a BMS overcurrent trip, not a dead battery. When the vacuum runs with restricted airflow — blocked nozzle, full dust cup, or clogged filter — the motor labours and current spikes above the BMS cutoff threshold. The BMS disconnects the pack momentarily, then resets once current drops. Clear the blockage and empty the dust cup. If the cutout stops after that, the battery is working exactly as it should.