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<p class=MsoNormal><font size=4 color=black face=Calibri><span
style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:black'>The
only way to do a capacity test is with a load bank over the rated discharge
period of the batteries, it they have a 6 hour rate, use that one. The 20 hour
rate takes too long! Voltage is a moving target and pretty much useless unless
the battery has been sitting with no charge or discharge for 12 hours or so,
and all that tells you is the state of charge nothing about the capacity of the
battery.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=4 color=black face=Calibri><span
style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:black'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=4 color=black face=Calibri><span
style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:black'>If you
are going to buy a load bank the old resistor load banks are the best choices,
the newer electronic units are too sensitive to damage and the failure rate is
quite high according to my suppliers. They have gone back to the resistor banks
in most cases. The load banks can test up to a 48 volt bank at one time, so you
don’t need to test each cell for 6 hours, you can spend 6 hours and test them
all at once! But your still going to spend 6 hours to do a correct test<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=4 color=black face=Calibri><span
style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:black'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=4 color=black face=Calibri><span
style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:black'>My
first experience with gels was bad enough to make me swear off them and that
was 18 years ago. I am sure they have I improved but most of my work is off
grid and flooded work best in that use.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=4 color=black face=Calibri><span
style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:black'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=4 color=black face=Calibri><span
style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:black'>Later,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=4 color=black face=Calibri><span
style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:black'>Bob Ellison<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=4 color=black face=Calibri><span
style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:black'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=4 color=black face=Calibri><span
style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:black'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=4 color=black face=Calibri><span
style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:black'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=4 color=black face=Calibri><span
style='font-size:14.0pt;font-family:"Calibri","sans-serif";color:black'><o:p> </o:p></span></font></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:"Tahoma","sans-serif";font-weight:bold'>From:</span></font></b><font
size=2 face=Tahoma><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
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>North Texas Renewable Energy Inc<br>
<b><span style='font-weight:bold'>Sent:</span></b> Monday, October 04, 2010
9:36 AM<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] Battery
capacity testers<o:p></o:p></span></font></p>
</div>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></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>
</div>
<div>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt;
font-family:"Arial","sans-serif"'>Todd</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt;
font-family:"Arial","sans-serif"'>I've heard the same arguement, as well as its
inverse. The battery choice was the decision of the system owner. I
know they are more sensitive to charge/discharge abuse but I see the full
charge rate last week at 52.xx V, just like day 1and
I trust the Trimetric and the Sunny Islands. We're taking down the entire
system to upgrade & install a 400A transfer switch so the batteries will
have time to stabilize for the VOC check & cleaning. </span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt;
font-family:"Arial","sans-serif"'>I guess a more accurate question would be is
it good enough to properly check cell VOC and not bother with the
discharge capacity check? A compromise could be cap check 12V
blocks of cells instead of all 24 separately. Or is the capacity checker a
waste of money.</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt;
font-family:"Arial","sans-serif"'>Jim</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face=Arial><span style='font-size:12.0pt;
font-family:"Arial","sans-serif"'> </span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> ----Original
Message-----<br>
<b><span style='font-weight:bold'>From:</span></b> 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> Monday, October 04, 2010
2:23 AM<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] Battery
capacity testers<o:p></o:p></span></font></p>
</div>
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'>
<p class=MsoNormal style='margin-bottom:13.5pt'><font size=4 face=Arial><span
style='font-size:13.5pt;font-family:"Arial","sans-serif"'>I know many on this list
disagree, but this sounds SO typical for sealed batteries. It is why I never
use em... never! If they are 5 years old, you are probably at the limit of
their life. Replace em with flooded lead calciums and your customers (and you)
will be happy for 20+ years.<br>
<br>
my .o2<br>
<br>
Todd<br>
<br>
<br>
<br>
On Sunday, October 3, 2010 9:28pm, "North Texas Renewable Energy Inc"
<ntrei@1scom.net> said:<o:p></o:p></span></font></p>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'>I have a customer with a set of 24 Concord
PVX-6480s that have twice failed during grid outages during the night. No large
loads are on the critical load panel and, since it's at night when they drop to
50% dod, I'm not sure what's up with them. I plan on cleaning and retightning
all the cable connections first to eliminate that possibility then
checking VOC of each cell. <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'>Eventually we'll install a 25 kW genset but
my first task is to find out the state of the batterys. The system turns five
next spring so I don't think they are near an early death. The BOS is 2
Sunny Island 4248s with upgraded chipsets and the charger is set to spec though
that may need to be bumped up. The only culprit I suspect is the high
summer temperatures in this unconditioned equipment room. <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'>Finally it may be time to invest in a
capacity tester. What brand is popular among those Wrenches with lots
of experience in diagnosing a batterys health? The Concord DC5000 only
comes in 12 & 24 V models and these are 2V cells. <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'>Thanks as always<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'> <o:p></o:p></span></font></p>
</div>
<div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'>Jim Duncan<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'>North Texas Renewable Energy<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'>486 W.N. Woody Road<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'>Azle Texas 76020<o:p></o:p></span></font></p>
</div>
<div>
<div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'>NABCEP Certified Solar PV<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'>Installer No.31310-57<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'>TECL 27398<o:p></o:p></span></font></p>
</div>
</div>
</div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'><a href="mailto:ntrei@1scom.net">ntrei@1scom.net</a>
<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'>817.917.0527<o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'><a href="http://www.ntrei.com/">www.ntrei.com</a><o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=4 face=Arial><span style='font-size:13.5pt;
font-family:"Arial","sans-serif"'> <o:p></o:p></span></font></p>
</div>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
<br>
<br>
Sent from Finest Planet WebMail.<o:p></o:p></span></font></p>
</blockquote>
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