On Thu, 20 Mar 2008 13:48:28 -0400 in rec.crafts.metalworking, clare
at snyder dot ontario dot canada wrote,
There is SOME truth to the belief.
The concrete is generally colder than a wood board, causing the
battery to cool down unevenly and the acid to stratify over time. The
"heavy" acid goes to the bottom. The "light" water goes to the top.
This apparently can cause "stratification sulphation"

Right. I was wondering if anybody who knew was going to post.
Conditions have to be right for it to occur, which is probably why
so many don't understand it.