About this replacement
Dyson V7 / SV11 Series — 21.6V Li-ion Replacement Battery (968670-02)
This 21.6V 2500mAh lithium-ion battery replaces the original pack in Dyson V7 and SV11 series cordless stick vacuums, including V7 Motorhead Pro and V7 Total Clean. It fits the same battery bay and uses the same connector and BMS communication protocol as the factory pack. Capacity is 2500mAh (54Wh), matching the original specification.
- V7 and SV11 platform fit: All V7-series models share the same 21.6V cell architecture, battery bay geometry, and BMS handshake. A single replacement pack covers the full V7 range because Dyson held the connector and communication spec constant across those variants.
- Bench tested on actual hardware: We ran this pack through the V7 Motorhead Pro motor controller. The BMS negotiated correctly on first connect, cell balancing activated after the initial charge cycle, and overcurrent cutoff triggered at expected thresholds under simulated blockage load.
- Dock charging habit on V7 vacuums: Do not leave the V7 on its wall dock continuously. The V7 charging circuit does not cut off cleanly at 100% under prolonged dock contact — trickle current continues and accelerates cell degradation. Charge to full, then remove from dock.
Suction dropping before the battery indicator reaches low
The V7 motor controller pulls higher current the moment airflow is restricted — a partially blocked filter or full bin forces the motor to work harder at the same fan speed. This extra draw causes cell voltage to sag under load even when the pack is at 60–70% state of charge. The vacuum's indicator reads pack voltage at rest, not under load, so the gauge looks fine while suction is already weak. Clear the filter and empty the bin first; if sag continues on a clean machine, the pack itself has degraded and needs replacement.
Motor cuts out mid-use then recovers after a short pause
This is a BMS overcurrent trip, not a motor fault. When sustained suction restriction forces current above the BMS threshold — typically around 20A on the V7 — the pack shuts output to protect the cells, then resets after temperature drops. Repeated trips accelerate cell wear. Check the filter and cyclone assembly for blockage before assuming the battery is at fault. If the machine is clean and trips still occur, measure resting pack voltage; anything below 20V indicates a weak cell group that can no longer handle peak motor-start current.