Tefal TY9152 Cordless Vacuum Replacement Battery 25.9V 3400mAh

Tefal TY9152 / TY9171 / TY9179 Series — 25.9V Li-ion Replacement Battery (RS-2230001774)

This 25.9V, 3400mAh lithium-ion battery replaces the original pack in Tefal TY9152, TY9171, TY9179, and TY9152WO/2D1 cordless stick vacuums. It carries the OEM part number RS-2230001774 and slots into the same battery bay with the original connector and retention clip. Capacity is 88.06Wh — matching factory specification.

• TY9152 / TY9171 / TY9179 platform fit: These models share a common 25.9V battery rail, connector housing, and BMS communication protocol. The same pack runs across all three without any modification to the charging path or motor control board.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a TY9152 unit. The BMS handshook correctly with the charger on first contact, held the 25.9V nominal rail under sustained motor load, and triggered overcurrent protection cleanly when we simulated a blocked nozzle — no latching fault required.
• Dock charging on this vacuum: Do not leave the vacuum seated on the charging dock permanently. Continuous dock charging on this platform introduces trickle-charge heat at the cell level and accelerates capacity fade. Charge to full, then remove from the dock until the next use.

Suction dropping before the battery indicator shows low

On the TY9152 platform, the motor draws significantly more current when airflow is restricted — a partially blocked filter can push draw well above the motor's rated operating current. The BMS responds by throttling output voltage to stay within its discharge curve, which the vacuum's electronics read as a low-power state before the indicator registers a problem. The motor slows, suction drops, but the LED still shows charge remaining. Clean or replace the HEPA filter first — if suction recovers immediately, the battery and BMS are functioning correctly.

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

This is a BMS overcurrent trip, not a battery failure. When sustained suction restriction forces the motor to draw beyond the BMS overcurrent threshold, the pack shuts output off to protect the cells. After a few seconds, the BMS resets and allows restart. If it keeps happening, the fault is almost always airflow — check the filter, the nozzle, and the brush roll for blockages. A clear airflow path brings draw back within the BMS's 25.9V operating window and the cut-outs stop.