Odyssey batteries are maintenance- free military grade batteries offering unequaled performance over conventional batteries. Their 5 sec cranking power is 2-3x’s that of conventional batteries, even at -40°F. Their sealed AGM design means that they contain no free acid or gel of any kind; the electrolyte is absorbed in a glass mat. Thus, Odyssey batteries may be mounted in any orientation (except inverted) & may be shipped hazmat free (even by air). Odyssey batteries will maintain a 50% charge @ 70°F even after 2 yrs in storage & have fast-charge recovery. Service life: 6-10 yrs. Optional kit converts 6mm terminal threads to 3/8″ SAE. Aluminum hold down box may be mounted flat or upright. The PC-545 measures 6-7/8″ in length, 3-3/16″ wide, and 5-1/8″ tall.