Re: Lead-Acid batteries and concrete floors

["PETER VANDERWAL" <peterv@peoplepc.com>]

I apologize.  Since you quoted the entire message I naturally assumed you
were responding to the entire message.  Since the bulk of the message was
about temperature effects and the request for opinions immediately followed
the descriptions about temperature effects, I was expecting a response to
temperature effects.
Your reply didn't make any sense in regards to temperature so I assumed you
didn't read the entire message.

I'm going to go out on a limb here and assume you were only responding to
the first line of the message?

If this is the case I'd like to make a suggestion.  To avoid confusion,
could you state which part of the message you are responding to or, better
yet, only quote the part of the message you are responding to?  I understand
that some might find the previous sentence to be rude, it's not intended to
be.

Again I apologize if you found my response offensive,  I had thought that it
was relatively polite.

P.S.  The guy writing the "letter to the editor" claimed to have maintained
batteries on submarines.  He stated that the Navy was having some problems
with this because the metal decks of the sub were so good at conducting the
deep cold of the ocean.  Apparently they solved this problem by sticking
tubes down into the batteries that they would use to pass air bubbles into
the electrolyte, this would agitate it and keep it from stratifying.
I'm still not certain that a garage floor would be (relatively) cold enough
to cause much of a reaction.  I was kind of hoping someone would have some
empirical data on it.

> I still think you are dealing with "urban legend"
> Someone thought up a "plausible sounding" scenario to support the old
> legend, which had been true. Since it is not true with today's materials,
a
> new explanation was needed. If anything, I think you would find, having
the
> battery sitting on a "thermal mass" would stabilize it's temp, and result
in
> more uniform temps and less discharge.
>
> [BY THE WAY, YOU DON'T HAVE TO MAKE STATEMENTS LIKE THE FOLLOWING.:
>
> >>>Umm, read the WHOLE message.  Nothing is permeating the case except
cold,
> > and plastic isn't immune to cold.<<<
>
> You asked for opinion >> "So what do you folks think, sound reasonable?"<<
> and I gave my opinion based on 30 years of  servicing storage batteries]
>
>
>
> ----- Original Message -----
> From: "PETER VANDERWAL" <peterv@peoplepc.com>
> To: <ev@listproc.sjsu.edu>
> Sent: Friday, March 30, 2001 10:55 PM
> Subject: Re: Lead-Acid batteries and concrete floors
>
>
> > Umm, read the WHOLE message.  Nothing is permeating the case except
cold,
> > and plastic isn't immune to cold.
> >
> >
> >
> > > That used to be a true statement, when battery cases were rubber and
> > pitch.
> > > They would seep acid and form a conductive layer with the concrete,
> > > resulting in a parasitic discharge. Today, with impermeable plastic
> cases,
> > > it doesn't matter.
> > >
> > > Rich
> > >
> > >
> > > ----- Original Message -----
> > > From: "VanDerWal, Peter" <vanderwp@fhu.disa.mil>
> > > To: <ev@listproc.sjsu.edu>
> > > Sent: Friday, March 30, 2001 4:32 PM
> > > Subject: Lead-Acid batteries and concrete floors
> > >
> > >
> > > > I'm sure we've all heard that Lead-Acid batteries will go dead
quickly
> > if
> > > > you store them on concrete floods (i.e. in the garage).
> > > >
> > > > I'd pretty much assigned this to the "Old Wives" tale section since
> > nobody
> > > > could provide me with a credible explanation of why this was so or
any
> > > > verifiable tests indicating it was true.
> > > >
> > > > Well I was going through some old magazines and I found a letter to
> the
> > > > editor that actually provided a reasonable sounding explanation of
why
> > > this
> > > > happens.  I'm still not sure that they do go dead quicker on
concrete,
> > > since
> > > > I've not heard of anybody testing it, but if they do this sounds
like
> > why.
> > > >
> > > > The author pointed out that concrete floors tend to be colder than
the
> > > > ambient temperature.  I've noticed this, I believe it's due to
> > > evaporation.
> > > >
> > > > Anyway with the battery sitting on the floor, the bottom of the
> battery
> > > will
> > > > be colder than the rest of it.  This causes temperature
stratification
> > of
> > > > the electrolyte (different temperature layers).  The different
> > > temperatures
> > > > in the electrolyte leads to different specific gravity with the
colder
> > > fluid
> > > > at the bottom having a lower specific gravity than the warmer fluid
on
> > > top.
> > > > The different specific gravities will cause different voltage
> potentials
> > > > across the tops and bottoms of the plates.  With different voltage
> > > > potentials current will flow inside the battery and cause it to go
> dead
> > > > quicker.
> > > >
> > > > So what do you folks think, sound reasonable?
> > > >
> > > > P.S. If true I would suspect this has less effect on AGMs and Gel
> Cells.
> > > >
> > > >
> > > >
> > >
> > >
> >
> >
> >
>
>