TOMEFON TF-S450 Replacement Battery 14.8V 2600mAh

TOMEFON TF-S450 / TF-S550 / TF-S650 / TF-S850 — 14.8V Li-ion 2600mAh Replacement Battery

This is a 14.8V 2600mAh (38.48Wh) lithium-ion battery for the TOMEFON TF-S450, TF-S550, TF-S650, and TF-S850 cordless stick vacuums, plus five additional TF-series models. It restores power to a vacuum where the original cell has lost capacity or failed entirely. Voltage, connector, and BMS handshake match the original pack.

• TF-S450 through TF-S850 series compatibility: These models share the same 14.8V four-cell Li-ion architecture, identical connector housing, and the same BMS communication protocol — which is why one replacement cell covers the full range without modification.
• Bench tested on actual hardware: We ran this pack on a TF-S450 and monitored BMS behaviour through full discharge cycles. The protection circuit held cutoff at 12V under motor load and recovered cleanly to ready state after recharge, with no fault flags thrown.
• Dock charging habit on TF-series vacuums: Do not leave this vacuum sitting on the charging dock continuously between uses. The TF-series charger does not enter a true maintenance mode — it trickle charges, which compresses cell capacity faster than intermittent use cycles. Charge to full, then remove from the dock.

Suction dropping before the battery indicator reaches low on the TF-S450

This is a motor voltage sag issue, not always a depleted battery. When the filter is partially blocked, the motor draws more current than rated to maintain airflow. That elevated draw causes cell voltage to sag under load, and the motor slows — but the battery indicator reads the resting voltage, not the load voltage, so it still shows mid-charge. Clean or replace the filter first. If suction restores immediately after filter cleaning, the battery is not the root cause.

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

This is a BMS overcurrent trip, typically triggered by sustained restricted airflow — a blocked filter or a partial blockage in the intake path forces the motor to pull beyond the BMS current threshold. The protection circuit cuts power momentarily, then resets once current demand drops. It is not a faulty battery. Clear the blockage, then confirm the motor runs continuously at full speed. If trips continue after clearing the path, check that cell voltage at rest reads above 14.0V before restarting.