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<DIV><FONT size=2 face=Arial>Some charge energy is lost in heat and some in
coulombic efficiency.</FONT></DIV>
<DIV><FONT size=2 face=Arial>There are educational powerpoints, papers
and other information about batteries on the internet.</FONT></DIV>
<DIV><FONT size=2 face=Arial>See <A
href="http://en.wikipedia.org/wiki/Faraday_efficiency">http://en.wikipedia.org/wiki/Faraday_efficiency</A></FONT></DIV>
<DIV><FONT size=2 face=Arial>and <A
href="http://www.mpoweruk.com/soc.htm">http://www.mpoweruk.com/soc.htm</A></FONT></DIV>
<DIV><FONT size=2 face=Arial>and <A
href="http://web.mit.edu/mit_energy/resources/iap/MatSciOfRenewEnergy_Lecture2_Batteries_2006.pdf">http://web.mit.edu/mit_energy/resources/iap/MatSciOfRenewEnergy_Lecture2_Batteries_2006.pdf</A></FONT></DIV>
<DIV><FONT size=2 face=Arial>and <A
href="http://ecee.colorado.edu/~ecen4517/materials/Battery.pdf">http://ecee.colorado.edu/~ecen4517/materials/Battery.pdf</A></FONT></DIV>
<DIV><FONT size=2 face=Arial>and <A
href="http://users.ece.utexas.edu/~kwasinski/EE394V_DG_Fall2008_Week5%20part2.ppt#1">http://users.ece.utexas.edu/~kwasinski/EE394V_DG_Fall2008_Week5%20part2.ppt#1</A></FONT></DIV>
<DIV><FONT size=2 face=Arial>and for info about long series strings of batteries
see <A
href="http://www.battcon.com/PapersFinal2004/SymonsPaper2004.pdf">http://www.battcon.com/PapersFinal2004/SymonsPaper2004.pdf</A></FONT></DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
<DIV><FONT size=2 face=Arial></FONT> </DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=hugh@scoraigwind.co.uk href="mailto:hugh@scoraigwind.co.uk">Hugh</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=re-wrenches@lists.re-wrenches.org
href="mailto:re-wrenches@lists.re-wrenches.org">RE-wrenches</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, January 15, 2010 3:25
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [RE-wrenches] discharging
Rolls batteries</DIV>
<DIV><BR></DIV>
<DIV>hi</DIV>
<DIV><BR></DIV>
<DIV>We know that batteries deliver less amphours at low temperature and at
high currents. Volts drop quicker. That's my starting point.
My question that I still do not hear an answer to is this:</DIV>
<DIV><BR></DIV>
<DIV>If the battery is a bank account and its harder to get the money out in
cold weather and when you want to get your hands on a lot at once...
Does this actually mean that some of the money gets lost? What happens
to it? Is it perhaps available later when the bank warms up or the
demand gets less hectic? Is there really less money in there or does it
just seem like less due to the conditions?</DIV>
<DIV><BR></DIV>
<DIV>I notice that Ah capacity is actually defined as how much Amphours you
can get out before the battery reaches a certain terminal voltage. I am
wondering whether it is the ability to maintain voltage that is the limiting
factor whereas the chemicals in there can still deliver amphours, given
the right temperature and time later. You can certainly see recovery
take place when a battery warms up and/or operates on lighter loads.</DIV>
<DIV><BR></DIV>
<DIV>One last time what happens to the chemicals (lead and lead oxide) that
represent Amphours of charge in the battery plates? For me this is a
little bit like current of 10 amps entering one end of a piece of wire
and only 9 amps coming out the other end. I understand that the volts go
down due to voltage drop (in this analogy) but loss of current is entirely a
different matter.</DIV>
<DIV><BR></DIV>
<DIV>Thanks for any help with this rather obscure question.</DIV>
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