Tefal TY8812 Replacement Battery 18.5V 2600mAh Li-ion

Tefal TY8812 / TY8818 / TY8840 Series — 18.5V Li-ion Replacement Battery

This is an 18.5V 2600mAh (48.1Wh) lithium-ion battery for the Tefal TY8812, TY8813, TY8818, and TY8840 cordless handheld vacuum cleaners, plus 29 additional compatible models in the same family. It replaces the original cell when the vacuum loses suction strength mid-clean or stops holding charge entirely. Voltage and connector match the factory specification for this series.

• TY88-series platform compatibility: These models share the same 18.5V power rail, BMS handshake protocol, and battery housing form factor — the same cell services the full range without modification or adapter.
• Bench tested on actual hardware: We ran this battery through charge cycles and motor-load draws on a TY8812 unit. The BMS held stable under sustained suction load and triggered cutoff correctly when the motor was blocked — no false trips on clean airflow.
• Dock charging habit for TY88-series vacuums: Do not leave this vacuum sitting on the charging dock after it reaches full charge. Continuous trickle charge from the dock accelerates capacity fade in Li-ion cells. Charge to full, then remove the vacuum from the dock until the next use.

Cordless vacuum losing suction before the battery indicator reaches low

This happens when the motor draws more current than the battery can deliver at its present state of charge — voltage sags under load even though the indicator still shows capacity remaining. A partially blocked filter makes this worse: restricted airflow forces the motor to work harder, pulling more amps and dropping cell voltage faster. The BMS reads the voltage sag as a low-battery condition and throttles output before the indicator catches up. Clean the filter first, then test suction — if it holds steady the battery is fine; if suction still drops early, the cell has degraded below its rated capacity.

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

This is an overcurrent trip, not a dead battery. When suction is restricted — blocked nozzle, clogged filter, or carpet fibres jamming the brush — the motor stalls momentarily and pulls a current spike the BMS treats as a fault. The BMS shuts output down, the motor stops, and after the cell recovers slightly it resets and allows the vacuum to restart. Clear the blockage completely and check the filter is clean and seated correctly. If cut-outs continue on an unobstructed vacuum with a new battery, measure pack voltage at rest — it should sit above 20V after a full charge.