OER Parts offers a wide selection of Battery Accessories for your 1966 Mercury Cyclone. OER Parts offers 1966 Mercury Cyclone Battery Tender, 1966 Mercury Cyclone Battery Managment System, 1966 Mercury Cyclone Dual Battery System Controller Set, and 1966 Mercury Cyclone Battery Relocation Set. Battery Mat Battery Topper Battery Terminal Protectors Battery Post Cleaning Brush Battery Terminal Puller