Battery terminals corroding quickly

Battery terminals that corrode faster than seems normal usually point to a slow acid leak (on lead-acid/AGM) or just inadequate protection from moisture and road grime. Terminal protector spray or grease after cleaning helps a lot, but if corrosion is genuinely fast (weeks, not months), check for a cracked case or overfilled cell venting acid vapor. How quickly is it building up, and is it one terminal or both?