Re: (ET) How NOT to check your batteries...

["RJ Kanary" <rjkanary nauticom net>]

The following should help, obtained from:
http://en.wikipedia.org/wiki/Lead-acid_battery
[edit] Separators
Separators are used between the positive and negative plates of a lead acid 
battery to prevent short circuit through physical contact, mostly through 
dendrites ('treeing'), but also through shedding of the active material.

Separators obstruct the flow of ions between the plates and increase the 
internal resistance of the cell.

Various materials have been used to make separators:

 a.. wood
 b.. rubber
 c.. glass fiber mat
 d.. cellulose
 e.. sintered PVC
 f.. microporous PVC/polyethylene.
An effective separator must meet a number of mechanical properties. 
Permeability, porosity, pore size distribution, specific surface area, 
mechanical design and strength, electrical resistance, ionic conductivity, 
and chemical compatibility with the electrolyte. In service the separator 
must have good resistance to acid and oxidation. The area of the separator 
must be a little larger than the area of the plates to prevent material 
shorting between the plates. The separators must remain stable over the 
operating temperature range of the battery

----- Original Message ----- 
From: "Jeremy Gagliardi com" <jeremy gagliardi com>
To: <elec-trak cosmos phy tufts edu>
Sent: Tuesday, August 07, 2007 8:01 AM
Subject: Re: (ET) How NOT to check your batteries...


> I don't know what separator damage is.
>
> David Roden wrote:
> > > Probably not.  Shed lead sulfate is relatively heavy and it doesn't 
> > > float.
> > > It
> > > sinks to the bottom of the cells.  If the battery gets enough vibration,
> > > it may
> > > get stirred up, and give the electrolyte a grey color.
>
> Stirred up?  The water was bubbling.  Could that do it?
>
> The water was a bit greyish.
>
> --
> Jeremy Gagliardi
> E20
> Potomac, Md
>
> > ----Original Message----
> > From: rjkanary nauticom net
> > Date: Aug 6, 2007 16:19
> > To: <elec-trak cosmos phy tufts edu>
> > Subj: Re: (ET) How NOT to check your batteries...
> >
> > He may be seeing the result of separator damage. Time will tell. :(
> >
> > RJ
> >
> >
> > ----- Original Message ----- 
> > From: "David Roden (Akron OH USA)" <etpost drmm net>
> > To: <elec-trak cosmos phy tufts edu>
> > Sent: Monday, August 06, 2007 1:25 PM
> > Subject: Re: (ET) How NOT to check your batteries...
> >
> >
> > > > with every battery having low water in at least 1 cell, the voltage
> > > > had severely dropped, and keeping my ET plugged in
> > > > with the automatic Landis Controller, unsupervised, the charger
> > > > had been constantly cycling on & off over the course of countless
> > > > days, boiling away my batteries.
> > >
> > > I've said it before - Harry Landis's device may have some applications 
> > > in
> > > certain circumstances, but it's *not* a charge controller.  Its 
> > > algorithm
> > > is
> > > intriguing and original, but it doesn't implement the charging
> > > instructions of
> > > any battery manufacturer.
> > >
> > > It also has fairly minimal "smarts."  Most microprocessor based charge
> > > controllers have safety limits.  They can say to themselves, "Uh-oh, 
> > > I've
> > > been
> > > charging for 19 hours, and not only is the battery voltage still not up 
> > > to
> > > where
> > > it should be, now the voltage is actually *falling*.  I guess 
> > > something's
> > > wrong.
> > > I'd better stop the charge and turn on my 'fault' light."  The Landis
> > > device has
> > > no such safeguard.
> > >
> > > Of course, the original GE charger is even dumber.  ;-)
> > >
> > > > I saw "things" floating in the water.  Is that the legendary
> > > > sulfation I've heard so much about?
> > >
> > > Probably not.  Shed lead sulfate is relatively heavy and it doesn't 
> > > float.
> > > It
> > > sinks to the bottom of the cells.  If the battery gets enough vibration,
> > > it may
> > > get stirred up, and give the electrolyte a grey color.
> > >
> > > I'm not an electrochemist, but I'd guess that your grids corroded from
> > > being
> > > exposed to air, and you're seeing some of the corrosion flaking off.
> > >
> > > > When I bought my batteries, they didn't come with an instruction
> > > > manual, or even a tip sheet.
> > >
> > > You could buy a copy of the Curtis Battery Book One.  I think it may be
> > > out
> > > of print now, but some of the EV parts vendors may still have copies to
> > > offer.
> > >
> > > You can also get an excellent introduction to the basics of lead 
> > > batteries
> > > from Witte's "The Automobile Storage Battery: Its Care and Repair,"
> > > published in 1922.  It's now in the public domain and you can read the
> > > entire
> > > text on the web here :
> > >
> > > http://www.powerstream.com/1922/battery_1922_WITTE/battery_WITTE.htm
> > >
> > >
> > >
> > > _______________________________________________
> > > Elec-trak mailing list
> > > Elec-trak cosmos phy tufts edu
> > > https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
> >
> >
> > _______________________________________________
> > Elec-trak mailing list
> > Elec-trak cosmos phy tufts edu
> > https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
>
>
>
> _______________________________________________
> Elec-trak mailing list
> Elec-trak cosmos phy tufts edu
> https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak