On Fri, 21 Mar 2008 23:51:02 -0600 in rec.crafts.metalworking, Don
Foreman wrote,
I don't know anything about how or if stratification would cause
plates to "sulfate" or whatever.

Remaining in a discharged state for any length of time is what
causes the plates to form large hard crystals of lead sulfate,
usually irreversibly.