baking soda bath... rinse with distilled... a little elbow grease and sandpaper/wire wheel/whatever you choose(battery terminal cleaners are pretty dang effective!) and good as new! I helped a friend swap batteries in his semi, they were way worse! So far gone the acid had ate half the stands in the cables so it turned into a rewire job with new jumper cables between batteries, new ground, and new positive to the charging system. Peeled back the jacket on the positive wire and the acid had eaten strands back 4 feet!