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