Shark XSBT420 14.4V Cordless Vacuum Replacement Battery 1800mAh

Shark QV410 Series — 14.4V Li-ion Replacement Battery (XSBT420)

This is a 14.4V, 1800mAh Li-ion replacement battery for the Shark QV410 series cordless stick vacuum. It fits the QV410QBK, QV410QBL, QV410QCP, QV410QGR, and more than twenty additional QV410 variants. Swap it when the original cell can no longer hold enough charge to complete a cleaning session.

• QV410 series compatibility: All QV410 variants share the same 14.4V voltage rail, connector pinout, and BMS handshake protocol. That single architecture is why one part number — XSBT420 — covers the full range without modification.
• Bench tested on actual hardware: We ran this cell through charge cycles on a QV410 dock and monitored BMS communication. The protection circuit responded correctly to full-charge cutoff and recovered cleanly from a simulated low-voltage condition without requiring a reset.
• Dock charging habit on the QV410: The QV410 dock does not switch to a true maintenance mode after the cell reaches full charge. Leaving the vacuum on the dock permanently exposes the Li-ion cells to continuous trickle current, which accelerates capacity fade. Charge to full, then remove from the dock.

Suction dropping before the battery indicator reaches low on the QV410

The QV410 motor draws significantly more current when airflow is restricted — a partially clogged filter forces the motor to work harder against back-pressure. That extra draw causes the cell voltage to sag under load, which the vacuum interprets as a low-battery condition before the actual state of charge warrants it. The battery indicator is reading real-time voltage under load, not stored capacity. Clean or replace the foam and felt filters first; if the suction and indicator behaviour return to normal, the battery was not the problem.

Motor cutting out mid-clean then recovering after a few seconds

This is a BMS overcurrent trip, not a dead battery. When the QV410 motor sustains a restricted airflow condition — a blocked hose, packed filter, or deep-pile carpet with no airflow — current draw spikes past the BMS threshold and the protection circuit opens to prevent cell damage. The motor stops, the BMS resets after a few seconds, and power returns. The fix is not a new battery. Clear the blockage, check the filter, and confirm airflow is unobstructed before running the vacuum again.