Tineco Pure One S11 Smart Replacement Battery 21.6V VS15-02

Tineco Pure One S11 Smart / S15 Series — 21.6V Li-ion Replacement Battery (VS15-02)

This 21.6V 2500mAh (54Wh) Li-ion battery fits the Tineco Pure One S11 Smart, Pure One S11 Tango, Pure One S15, and Pure One S15 Pet cordless stick vacuums. It replaces OEM part VS15-02 and 9VSPT150000. Capacity figures come from the product data — not estimated from third-party sources.

• S11 and S15 platform compatibility: These models share the same 21.6V battery bay, connector pinout, and BMS handshake protocol. Swapping between them does not require any adapter or firmware change — the pack communicates charge state to the LED indicator on all listed models.
• Bench tested on actual hardware: We ran this pack through full charge and discharge cycles on the S11 Smart platform. The BMS held cell balancing across the full discharge curve and triggered low-voltage cutoff at the correct threshold without false trips under sustained suction load.
• Dock charging behaviour on the S11 and S15: Remove the vacuum from the charging dock once the battery reaches full charge. Leaving it docked continuously applies a trickle current that accelerates capacity fade in Li-ion cells at this voltage — charge only when depleted and disconnect when full.

Cordless vacuum losing suction before the battery indicator reaches low

This happens when the motor draws more current than the pack can sustain at its current state of charge — not because the cells are empty. On the S11 and S15, a partially blocked filter forces the motor to work harder, spiking current draw above the BMS threshold. The BMS throttles output voltage to protect the cells, and suction drops noticeably even though the indicator still shows two bars. Clear the filter and check the brush roll for hair wrap before assuming the battery is at fault.

Motor cutting out mid-clean and recovering after a few seconds

This is a BMS overcurrent trip, not a dead battery. The S11 and S15 motors pull a short high-current spike when suction is restricted — a blocked filter or tangled brush roll pushes that spike past the BMS cutoff limit. The pack disconnects to protect the cells, then resets after the current drops, which is why the vacuum restarts seconds later. Clean the filter and remove any obstruction from the brush roll, then restart — if the trip does not recur, the pack is functioning correctly.