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<DIV><FONT face=Arial size=2>Roy,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Your post is most puzzling. As temperatures
rise above 25C, battery capacity rises and cycle life is shortened. The opposite
is true as temperatures drop below 25C. What do you mean by he was loosing
"capacity" during summer months? </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>My question is whether anyone has run air
conditioning on a battery bank to increase the cycle life, not capacity, in
hot climates.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>As of my last conversation with the customer, he is
willing to insulate the small battery room and put in a portable A/C unit. I
measured one unit that only drew 620 watts while cooling. I expect that
with sufficient insulation, the A/C will only run a few hours per
day. The home is vacant for 3-4 weeks then used for 3-5 days.
The DoD is only 5% while vacant. The PV charging system is oversized
now and should keep up with the extra load. I'll post again in about 3 to
4 years to let you know if this plan works!</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thanks for everyone's input.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Larry</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=roy@four-winds-energy.com href="mailto:roy@four-winds-energy.com">Roy
Butler</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@lists.re-wrenches.org</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, April 22, 2011 10:09
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [RE-wrenches] Air
conditioning for batteries in high temperature climate</DIV>
<DIV><BR></DIV>Bob is correct, I do have an off grid client that uses an AC
unit to keep the batteries cool.<BR>Although we're not in a high temp climate,
it does get into the 80's and low 90's here<BR>in the summer. <BR><BR>By my
calculations, he was losing an 'average' of 10% storage capacity during the 5
month<BR>period from late spring to early fall. In July and August it was
closer to 18%, but for calculation<BR>purposes, 10% is close enough. His bank
capacity is 4800AH @ 48 VDC. That's 230,400 watt hours <BR>and 10% of that
rounds out to 23,000 watt hours lost to heat. <BR><BR>I showed up one day to
check something in the power shed and was dismayed to see a window <BR>AC unit
installed there. An interesting customer discussion ensued and I had to admit
he was <BR>correct in his calculations.<BR><BR>The Energy Star rated AC unit
consumes no more than 3,000 watt hours per day, even in the<BR>highest heat.
Essentially, he's 'spending" 3 kilowatt hours to 'buy back' 20 kilowatt hours
of<BR>storage. He got me on that one!<BR><BR>That reasoning didn't work on the
6 other AC units that appeared on his house the following<BR>week. But that's
another story altogether!<BR><PRE class=moz-signature cols="72">Roy Butler
NABCEP Certified Solar PV Installer®
NYSERDA eligible PV & wind installer
PA Sunshine Program Approved PV Installer
Four Winds Renewable Energy, LLC
8902 Route 46
Arkport, NY 14807
607-324-9747
</PRE>
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<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">Hello Battery
Wrenches,</SPAN></FONT><FONT face=Helvetica size=4><SPAN
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<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'Arial','sans-serif'">Over the years I
have had several battery banks in Baja and Sonora Mexico fail in
just 36 to 48 months. These have been L16 or 8D AGM or flooded banks,
24 and 48 volt systems. The charging systems are working properly and
programmed to manufacturer recommended set points and
discharges are rarely over 30% DoD. Some batteries are only used
on weekends, some are discharged daily. I believe what is affecting
the short life is the high temperature they live in for 5 months each year.
Temps. can hit 115 F in vented battery rooms. I have been thinking about a
small air conditioner and insulated battery box to keep the battery at
no more than 80 F. There are some portable units that draw about 600 watts
and the run time would be very little with a highly insulated enclosure.
There is ample power to do this on the home I am changing batteries in now.
Has anyone done this and gained longer battery life?</SPAN></FONT><FONT
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<P class=MsoNormal><FONT face=Verdana size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'Verdana','sans-serif'">Best
Regards,</SPAN></FONT><FONT face=Helvetica size=4><SPAN
style="FONT-SIZE: 13.5pt; FONT-FAMILY: 'Helvetica','sans-serif'"><O:P></O:P></SPAN></FONT></P></DIV>
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<P><FONT face=Verdana size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'Verdana','sans-serif'">Larry
Crutcher<BR><A href="http://www.starlightsolar.com/"
moz-do-not-send="true">Starlight Solar Power
Systems</A><BR></SPAN></FONT><FONT face=Georgia size=1><SPAN
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