Symbo D300B 14.4V Replacement Battery 2600mAh Li-ion

Symbo D300B / D400 / D410 Series — 14.4V Li-ion 2600mAh Replacement Battery

This is a 14.4V Li-ion battery rated at 2600mAh (37.44Wh), built to replace the original cell in Symbo cordless stick and handheld vacuums. It fits the D300B, D400, D410, and related models in that line. When the original battery no longer holds a useful charge, this unit restores full motor voltage to the vacuum.

• D300B / D400 / D410 platform fit: These models share the same 14.4V battery rail, connector pinout, and BMS communication protocol. Swapping between them works because the charging circuit and discharge curve are identical across the series.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the D300B platform. The BMS handshake completed correctly on first contact with the charger, and the protection circuit tripped cleanly at the rated low-voltage cutoff with no false trips during motor start-up.
• Dock charging behaviour on this vacuum: Do not leave the vacuum seated on the charging dock continuously. Symbo stick vacuums on permanent dock charge develop capacity fade faster than units charged only when the battery is depleted. Charge to full, then remove from the dock.

Cordless vacuum losing suction before the battery indicator reaches low

This happens when the motor draws more current than the battery can sustain at its present state of charge, causing voltage to sag below what the motor needs for full suction — even though the indicator still reads mid-charge. A partially blocked filter makes it worse because restricted airflow forces the motor to work harder and draw higher current. The BMS reads that current spike as a stress event and may briefly reduce output to protect the cell. Clean the filter first, then check whether suction improves across a full charge cycle.

Motor cuts out during use then restarts after a short pause

This is a BMS overcurrent trip, not a dead battery. When the vacuum is run on thick carpet or with a partially blocked airway, sustained motor load pushes current draw past the BMS trip threshold. The protection circuit cuts power, the cell recovers, and the vacuum starts again. The fix is to clear the filter and check the brush roll for tangled debris — both cause sustained high-draw conditions. If the trip still occurs on a clean machine, verify the charger output is reaching 16.8V, which confirms the cell charged to the correct top voltage before use.