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<p class=MsoNormal><font size=3 color=green face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:green'>Todd:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=green face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:green'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=3 color=green
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:green'>Here’s the long story. </span></font><font color=green
face="Arial Rounded MT Bold"><span style='font-family:"Arial Rounded MT Bold";
color:green'>First the bulk charge brings the bank to an 80% charging level. The
charger will maintain current level until the bulk set point has been reached.
Then, the charger will switch to the absorption timer. <o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=3 color=green
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:green'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=3 color=green
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:green'>The absorb mode takes care of the remaining 20% of the capacity,
and is a function of time and current. This needs to be programmed, or at least
checked, by the installer. To me this is the most important charge rate because
as you see if this is not correct the batteries really don’t have any chance of
a long life.<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=3 color=green
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:green'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=3 color=green
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:green'>Most folks think that the absorption mode is some function of sensing
by the Charge Controller or Inverter/Charger. it is not. The absorb mode is governed
only by what ever the installer or the factory programs. Like I said earlier
the typical default setting is always way too short. <o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=3 color=green
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:green'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=3 color=green
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:green'>So what usually happens is the charger goes through the bulk
charge, then switches to absorb, holds it there for a too brief period, then
goes to float. The batteries never get full charged so they begin to hard
sulfate and the usual scenario goes like this; after a few years the customer
calls and says the batteries are bad because they’re loosing capacity<o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=3 color=green
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:green'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><font size=3 color=green
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:green'>In the absorb mode the current levels start decreasing as the
internal resistance in the battery increases. I assume over the time of the
absorption charge that 50% of the maximum charge current will be available
(this is factored into the equation<b><span style='font-weight:bold'>). <o:p></o:p></span></b></span></font></p>
<p class=MsoNormal align=center style='text-align:center;text-autospace:none'><b><font
size=3 color=green face="Arial Rounded MT Bold"><span style='font-size:12.0pt;
font-family:"Arial Rounded MT Bold";color:green;font-weight:bold'><o:p> </o:p></span></font></b></p>
<p class=MsoNormal style='text-autospace:none'><b><font size=4 color=green
face="Arial Rounded MT Bold"><span style='font-size:14.0pt;font-family:"Arial Rounded MT Bold";
color:green;font-weight:bold'>t = 0.42* C/1</span></font></b><font size=4
color=green face="Arial Rounded MT Bold"><span style='font-size:14.0pt;
font-family:"Arial Rounded MT Bold";color:green'><o:p></o:p></span></font></p>
<p class=MsoNormal style='text-autospace:none'><b><font size=3 color=green
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:green;font-weight:bold'><o:p> </o:p></span></font></b></p>
<p class=MsoNormal style='text-autospace:none'><b><font size=3 color=green
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:green;font-weight:bold'>Where:<o:p></o:p></span></font></b></p>
<p class=MsoNormal style='text-autospace:none'><b><font size=3 color=green
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:green;font-weight:bold'>t = Absorption Charge Time<o:p></o:p></span></font></b></p>
<p class=MsoNormal style='text-autospace:none'><b><font size=3 color=green
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:green;font-weight:bold'>C = 20hr Rated Capacity<o:p></o:p></span></font></b></p>
<p class=MsoNormal style='text-autospace:none'><b><font size=3 color=green
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:green;font-weight:bold'>I = Charging Current<o:p></o:p></span></font></b></p>
<p class=MsoNormal><b><font size=3 color=green face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:green;
font-weight:bold'>0.42 = (20%/50%) + 5%. <o:p></o:p></span></font></b></p>
<p class=MsoNormal><font size=3 color=teal face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:teal'>5% is
added due to losses<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=teal face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:teal'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 color=green face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:green'>Some
Inverter/Chargers will only let you set an absorb time by telling it the AH
capacity of the battery bank. If this is too short just tell the inverter that
bank is larger and the time will go up. <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=green face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:green'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 color=green face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:green'>Also
some of the cheaper Inv/Chargers don’t let you select absorb volts either
except by type, I always select Wet Cell even if I have AGMs which ups the
voltage a small amount. <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=green face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:green'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 color=green face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:green'>Gel
cell batteries are another matter all together and can be over charged and
cooked easily.</span></font><font color=green face="Arial Rounded MT Bold"><span
style='font-family:"Arial Rounded MT Bold";color:green'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=green face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:green'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 color=green face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:green'><o:p> </o:p></span></font></p>
<div>
<p class=MsoNormal><b><font size=3 color=green face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:green;
font-weight:bold'> Tom Duffy</span></font><font color=green><span
style='color:green'><o:p></o:p></span></font></b></p>
<p class=MsoNormal><i><font size=3 color="#99cc00" face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:#99CC00;
font-style:italic'> Systems Design Engineer</span></font><font
color="#99cc00"><span style='color:#99CC00'><o:p></o:p></span></font></i></p>
<p class=MsoNormal><font size=3 color=green face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:green'><img
width=218 height=80 id="_x0000_i1026" src="cid:image001.jpg@01CB1932.4BA45070"></span></font><font
color=green><span style='color:green'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=green face="Arial Rounded MT Bold"><span
style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";color:green'> <a
href="mailto:tom@thesolar.biz">tom@thesolar.biz</a></span></font><font
color=green><span style='color:green'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=green face="Arial Rounded MT Bold"><span
style='font-size:11.0pt;font-family:"Arial Rounded MT Bold";color:green'>
</span></font><font color=green face="Arial Rounded MT Bold"><span
style='font-family:"Arial Rounded MT Bold";color:green'>575-539-2111 X 301</span></font><font
color=green><span style='color:green'><o:p></o:p></span></font></p>
<p class=MsoNormal><em><i><font size=3 color=teal face="Times New Roman"><span
style='font-size:12.0pt;color:teal'>Although no trees were killed in the
sending of this message, a large number of electrons were terribly
inconvenienced.</span></font></i></em><font size=2 color=green
face="Arial Rounded MT Bold"><span style='font-size:11.0pt;font-family:"Arial Rounded MT Bold";
color:green'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=green face="Times New Roman"><span
style='font-size:12.0pt;color:green'> <o:p></o:p></span></font></p>
<p class=MsoNormal><strong><b><font size=3 color="#993300"
face="Arial Rounded MT Bold"><span style='font-size:12.0pt;font-family:"Arial Rounded MT Bold";
color:#993300'>Confidentiality Notice</span></font></b></strong><font
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color:#993300'>:</span></font><font color=green face="Arial Rounded MT Bold"><span
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face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center tabindex=-1>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
re-wrenches-bounces@lists.re-wrenches.org
[mailto:re-wrenches-bounces@lists.re-wrenches.org] <b><span style='font-weight:
bold'>On Behalf Of </span></b>toddcory@finestplanet.com<br>
<b><span style='font-weight:bold'>Sent:</span></b> Wednesday, June 30, 2010
10:29 PM<br>
<b><span style='font-weight:bold'>To:</span></b> RE-wrenches<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [RE-wrenches]
Interstate UL-16 HC problem</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:Arial'>"</span></font><font color=green
face="Arial Rounded MT Bold"><span style='font-family:"Arial Rounded MT Bold";
color:green'>proper absorb times (do the math)"<br>
<br>
Can you talk more about this please.<br>
<br>
Todd</span></font><font size=4 face=Arial><u1:p></u1:p><u1:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City"><u1:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"><span
style='font-size:13.5pt;font-family:Arial'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"></u1:smarttagtype></u1:smarttagtype><span
style='font-size:12.0pt'><br>
<u2:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City"><u2:smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"></u2:smarttagtype></u2:smarttagtype><br>
<br>
Sent from Finest Planet WebMail.<o:p></o:p></span></font></p>
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