OER Parts offers a wide selection of Battery Accessories for your 1973 Mercury Montego. OER Parts offers 1973 Mercury Montego Battery Tender, 1973 Mercury Montego Battery Managment System, 1973 Mercury Montego Dual Battery System Controller Set, and 1973 Mercury Montego Battery Relocation Set. Battery Mat Battery Topper Battery Terminal Protectors Battery Post Cleaning Brush Battery Terminal Puller