Replacement Battery for Dyson V8 Vacuums This Masters Instruments replacement battery is suitable for compatible Dyson V8 vacuum cleaners, including the V8 Animal and V8 Absolute. It features a 21.6V lithium-ion battery with a nominal capacity of 4Ah (86.4Wh). Check your vacuum model and existing battery part number against the compatibility lists below before ordering. Battery Specifications Brand Masters Instruments