About this replacement
Dyson V8 Range — 21.6V Li-ion Replacement Battery (215681)
This is a 21.6V, 5000mAh (108Wh) lithium-ion replacement battery for the Dyson V8 cordless vacuum range, including the V8 Animal and V8 Absolute. It fits the full V8 lineup using OEM part numbers 215681, 215967, 215866, and 967834-02. When the original cell degrades and the vacuum loses suction well before the indicator drops, this is a direct cell replacement.
- V8 range fit — Animal, Absolute, and standard V8: All V8 models share the same 21.6V battery rail, connector footprint, and BMS handshake protocol. One battery services the entire V8 lineup without modification or adapters.
- Bench tested on actual hardware: We ran this cell on a V8 Absolute under sustained high-torque load. The BMS held the discharge curve steady across the full cycle and tripped correctly at the low-voltage cutoff threshold — no mid-cycle shutdowns and no false low-battery flags.
- Dock charging habit for V8 owners: Do not leave the V8 sitting on the wall dock permanently. The V8 dock delivers a continuous trickle charge once full, which accelerates cell degradation over months. Charge to full, then remove the vacuum from the dock until the next use.
Suction dropping hard before the battery indicator reaches low
The V8 motor draws a spike of current whenever suction is restricted — a blocked filter or partial clog forces the motor to work harder to maintain airflow. If the battery cell is aged or a new cell is poorly matched to the BMS, voltage sags under that spike and the vacuum interprets it as a low-charge condition. The result is reduced suction or a shutdown even when the indicator shows two or three bars remaining. Before replacing the battery, wash the filter and clear any blockage in the bin or wand — then retest. If the problem persists with a clean filter, the cell itself is the cause.
V8 motor cuts out briefly then recovers mid-clean
This is a BMS overcurrent trip, not a flat battery. When the filter is partially blocked, the motor sustains a draw above its rated current ceiling — the BMS cuts power to protect the cell, then resets after a second or two. It looks like a battery fault but is almost always a filter restriction. Remove and rinse the filter, let it dry fully for at least 24 hours, and reinstall. If cutouts stop after a clean filter is back in, the battery was not the fault.