V-tac VT-5555 Cordless Vacuum Compatible Battery 14.4V 3400mAh

V-tac VT-5555 / VT-5556 — 14.4V Li-ion Replacement Battery

This is a 14.4V 3400mAh (48.96Wh) lithium-ion battery for the V-tac VT-5555 and VT-5556 cordless stick vacuums. It slots into the same battery bay as the original and uses the same connector orientation. Fits both models because they share an identical 14.4V motor rail and battery housing.

• VT-5555 and VT-5556 compatibility: Both models run the same 14.4V brushless motor platform and use the same battery bay, connector, and BMS communication protocol. One battery covers both units without modification.
• Bench tested on actual hardware: We cycled this cell through repeated discharge loads matching the VT-5555 motor draw. The BMS held voltage steady across normal floor and carpet cycles and cut off cleanly at the low-voltage threshold without tripping early.
• Dock charging habit on cordless vacuums: Do not leave the vacuum sitting on the charging dock permanently. Continuous trickle charging accelerates capacity fade on Li-ion cells faster than regular charge-and-remove cycles. Charge to full, then pull the unit off the dock.

Suction dropping before the battery indicator hits low

This happens when the motor is working against a restriction — a clogged filter, a blocked brush roll, or a partially sealed dustbin. The motor draws more current than rated, voltage sags under load, and suction weakens well before the battery is actually depleted. The battery indicator reads remaining charge at rest voltage, not under the elevated draw. Clear the filter and brush roll first — if suction recovers immediately, the cell is fine.

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

This is a BMS overcurrent trip, not a dead battery. When suction is sustained against a blockage — especially on thick carpet — current spikes past the BMS protection threshold and it shuts the output to protect the cells. The BMS resets itself after a short cooldown, which is why power returns within seconds. Check the filter and brush roll for blockage, clear them, and confirm the restart voltage reads above 12.8V on a multimeter at the battery terminals.