Kyvol Cybovac S31 Replacement Battery 14.4V 6700mAh

Kyvol Cybovac S31 — 14.4V Li-ion Replacement Battery

This 14.4V, 6700mAh lithium-ion battery fits the Kyvol Cybovac S31 robotic vacuum cleaner. It replaces the original cell pack when capacity has dropped to the point where the unit can no longer complete a full cleaning cycle. Dimensions are 132.00 x 40.00 x 37.20mm — confirm fit before installing.

• Cybovac S31 platform fit: The S31 runs its drive motors and suction motor from the same 14.4V rail. A replacement cell must match that voltage exactly — a mismatch trips the BMS before the unit starts its cleaning routine.
• Bench tested on actual hardware: We ran this pack through charge and discharge cycles on S31-compatible hardware. The BMS responded correctly to both low-voltage cutoff and overcurrent conditions on motor start.
• Dock charging habit on the S31: Do not leave the S31 sitting on the dock permanently between uses. Continuous trickle charging on this cell chemistry accelerates capacity fade. Charge to full, then remove from the dock until the next cleaning session.

Suction dropping before the battery indicator reads low

The S31's suction motor draws peak current when transitioning from hard floor to carpet or when the filter is partially blocked. If the battery cell pack has aged, its internal resistance rises — and under that surge, pack voltage sags below what the motor controller expects. The unit responds by reducing suction power even though the indicator still shows a charge. A fresh cell with lower internal resistance holds the voltage rail steady through those demand spikes and restores full suction output.

Motor cuts out mid-cycle then restarts after a pause

This is a BMS overcurrent trip, not a mechanical fault. When the filter restricts airflow, the suction motor works harder to maintain speed — sustained current climbs past the BMS trip threshold, and the pack shuts output off to protect the cells. After a brief rest the BMS resets and the unit restarts. Clean or replace the filter first. If the fault persists with a clean filter, the cell pack can no longer sustain the motor's rated draw — replacing the battery resolves the cutoff.