Thanks. Very strange. This is the first I've heard of this problem.
The plates deteriorate with repeated charge/discharge cycles, but not
the electrolyte. The above URL is the only one I've seen that
mentions any form of electrolyte deterioration in lead acid batteries.
If it's really a problem, I would have expected to see warnings, lab
analysis, and storage life expiration times. I can see sulfidation in
the discharged condition causeing something that resembles premature
failure, but not in a fully charged battery as found in a UPS. Pardon
my cynicism, but I don't believe it's for real. I'll see if I can
find some details on the chemistry of such electrolyte deterioration.



I hadn't heard of that either, not that it couldn't happen, but the most
common cause of lead acid battery failure is sulfation of the plates.