How is that? I've always heard that corrosion around the battery terminal is related to how well the battery casing is sealed around the terminal. That is why, as battery quality has improved with most battery manufacturers, battery terminal corrosion is getting less and less common. Except for a side post battery in an Alero I used to drive, I haven't had it on any of my cars for many, many years.Neg(-) post/terminal corrosion means under charging.
Pos(+) post terminal corrosion means over charging.
Keeping a battery maintainer/tender on the battery will help to reduce or even eliminate sulphate buildup on posts & terminals.