Eureka 4238AZ Cordless Vacuum Replacement Battery 14.4V 3400mAh

Eureka 4238AZ — 14.4V Li-ion Replacement Battery

This is a 14.4V, 3400mAh lithium-ion battery for the Eureka 4238AZ cordless stick vacuum. It replaces the original cell when the vacuum no longer holds a charge or shuts off early during use. Voltage and capacity match the stock specification exactly.

• 4238AZ platform fit: The 4238AZ runs a 14.4V motor rail with a specific connector and BMS communication protocol. This battery matches that rail. Swapping a mismatched voltage pack — even slightly higher — can trigger the vacuum's protection circuit and prevent startup.
• Bench tested on actual hardware: We ran this cell through repeated motor-start cycles and sustained suction loads. The BMS handled current spikes at startup without tripping and held stable voltage through the discharge curve.
• Dock charging discipline: Do not leave the 4238AZ sitting on the charging dock continuously. Cordless vacuums kept on permanent dock charge develop capacity fade faster than those charged only when depleted. Charge to full, then remove.

Suction dropping before the battery indicator reaches low

A partially blocked filter forces the 4238AZ motor to draw more current than its rated load. The BMS reads that elevated draw as a near-depleted cell and reduces output voltage to protect the pack. Suction falls off noticeably even though the indicator still shows charge. Clean or replace the filter first — if suction recovers and the indicator stays stable, the battery is not the fault.

Motor cuts out mid-use then restarts after a short pause

This is a BMS overcurrent trip, not a dead battery. Sustained restricted airflow — from a blocked filter or full dustbin — pushes motor current above the BMS threshold. The circuit opens, the motor stops, and after the cell temperature drops briefly, the BMS resets and allows restart. Clear the blockage and empty the dustbin before assuming the battery is faulty. If the trip still occurs on an unrestricted machine, measure pack voltage at rest — a healthy cell should read between 15.8V and 16.8V after a full charge.