About this replacement
Shark C3 Mini / SNC-C3 Mini — 14.4V Li-ion Replacement Battery (18650B4-3400-4S)
This is a 14.4V 2600mAh Li-ion battery for the Shark C3 Mini cordless vacuum cleaner. It fits both the C3 Mini and SNC-C3 Mini variants and slots directly into the handle battery bay. Voltage and capacity match OEM part number 18650B4-3400-4S.
- C3 Mini and SNC-C3 Mini compatibility: Both models run the same 14.4V motor rail and use the same battery bay connector and BMS handshake, so one cell fits the full platform without any wiring or fitting differences.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the C3 Mini platform. The BMS responded correctly to the charger handshake, held full voltage under motor load, and triggered protection cutoff only at rated low-cell threshold — no false trips.
- Dock charging habit on the C3 Mini: The C3 Mini's charging dock has no automatic cut-off once the cell reaches full charge. Leaving the vacuum seated on the dock permanently feeds a trickle current into the pack. Remove it from the dock once the indicator shows full to slow capacity fade.
Suction dropping before the battery indicator reaches low
The C3 Mini's motor draws more current when airflow is restricted — a partially clogged filter forces the motor to work harder against back-pressure, pulling above its rated current draw. The BMS reads that surge as a voltage sag on the cell and begins throttling output before the battery itself is actually depleted. The indicator still shows charge remaining because cell voltage hasn't hit the cutoff threshold — the motor is just being starved. Clean the filter first; if suction recovers to full strength, the battery is not the cause.
Motor cutting out mid-clean then recovering after a short pause
This is a BMS overcurrent trip, not a dead battery. When sustained suction restriction causes current draw to exceed the pack's rated limit, the BMS disconnects the output to protect the cells. After a short pause, the cell voltage recovers and the BMS resets, allowing the motor to restart. The cycle repeats if the restriction isn't cleared. Check the filter and brush-roll for blockages — if the cutout stops after clearing them, the pack is functioning correctly. If cutouts persist with a clean filter, confirm resting cell voltage sits above 12V with a multimeter before replacing the battery.