<div dir="ltr">First time I've heard of something like this since starting in the off-grid business in 1994.<div>Closest I've done to 'rotating' batteries is switching which corners of a series/parallel bank are the main DC connectors.</div><div>I have noticed, on some occasions, the end cells may use a bit more water. As for cell failures on strings, ends, middles, no particular pattern here with my installations. I *would* say those main end connections are the most important to keep super clean and maintain really good,low resistance connections as in series/parallel setups these connections have the most heating/cooling from higher amperage.</div><div>At least your client has a couple easily deployable extra batteries if another somewhere in the bank fails! Especially with an aging battery bank.</div><div><br></div><div>As for the initial confusion on how these extras were wired in, thanks for the diagram. Slightly off topic, I have been running my home/office on NiFe cells for 5 months now and I feel pretty confident about working around their idiosyncrasies. My Outback and Midnite charge controllers couldn't care less what the output voltage is, but the Magnum inverter goes into panic mode when asked to reach the sweet spot of 1.65v per cell off of the backup generator, it assumes the world is ending at 1.6v per cell. Hopefully a Magnum firmware upgrade in the future can fix that.</div><div><br></div><div>Best regards;</div></div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><span style="font-size:12.8000001907349px">Dan Fink</span><div style="font-size:12.8000001907349px">Adjunct Professor, Ecotech Institute</div><div style="font-size:12.8000001907349px">IREC Certified Instructor™ for: </div><div style="font-size:12.8000001907349px">~ PV Installation Professional</div><div style="font-size:12.8000001907349px">~ Small Wind Installer</div><div style="font-size:12.8000001907349px">Executive Director, Buckville Energy</div><div style="font-size:12.8000001907349px">NABCEP / IREC / ISPQ Accredited Continuing Education Providers™<br><a href="tel:970.672.4342" value="+19706724342" style="color:rgb(17,85,204)" target="_blank">970.672.4342</a></div><br> </div></div></div></div></div></div>
<br><div class="gmail_quote">On Thu, Oct 1, 2015 at 1:22 PM, Allan Sindelar <span dir="ltr"><<a href="mailto:allan@sindelarsolar.com" target="_blank">allan@sindelarsolar.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div style="background-color:rgb(255,255,255);color:rgb(0,0,0)" bgcolor="#FFFFFF" text="#000000">
Larry,<br>
I don't know the answers to these questions, as I haven't yet been
to the site. This is a new customer, referred to me by another
company that doesn't do off grid - at least, not off grid that
works. When he told me how they were set up on the phone, my gut
response was "this sounds dumb, or I would have heard about it
before", but I kept quiet and only gently said what I wrote in my
post. I posted this question in order to have the Wrenches support
for any position I offer when I go there next week.<br>
<br>
Also, the batteries weren't an issue in asking me to do a service
call. I don't yet even know what the issues are, other than their
mention of wanting a backup generator and wanting me to check
configuration on an XW4024 that they recently added. I had been told
that they had "ten fork lift batteries", which isn't possible with
24V, so I asked questions about that and that led to this thread.<br>
<br>
If I can get any useful information about the batteries I'll post it
here. I'll try to check SG's and maybe even some sort of load test,
but likely off the clock, as battery trouble wasn't a presenting
issue when they asked for a service call.<br>
<br>
Larry, nice drawing below. What did you use, as I need to learn it
too?<span class=""><br>
Allan<br>
<br>
<div>
<div>
<p class="MsoNormal"><b>Allan Sindelar</b><br>
<span style="font-size:10.0pt"><a href="mailto:allan@sindelarsolar.com" target="_blank"></a><a href="mailto:allan@sindelarsolar.com" target="_blank">allan@sindelarsolar.com</a></span><br>
<span style="font-size:10.0pt">NABCEP Certified PV
Installation Professional<br>
NABCEP Certified Technical Sales Professional<br>
New Mexico EE98J Journeyman Electrician<br>
Founder (Retired), <span>Positive
Energy,
Inc.</span><br>
<b><a href="tel:505%20780-2738" value="+15057802738" target="_blank">505 780-2738</a> cell</b><br>
<br>
<b><u></u><u></u></b></span></p>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
</div>
</span><div><div class="h5"><div>On 10/1/2015 1:04 PM, Starlight Solar
Power Systems wrote:<br>
</div>
</div></div><blockquote type="cite"><div><div class="h5">
Since multiple batteries failed ("the one that always fails"), did
he buy one new battery each time and tie it to the old failing
one? Or, did he start with a new bank and create the parallel at
that time? Since he’s an “old timer” he may be mixing different
age batteries in the bank. I see this often in Mexico. If that’s
the case, it will be difficult to find any cause of failure.
<div>
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<img src="cid:part2.04030904.03080802@sindelarsolar.com" height="304" width="240"><br>
<div>
<div>On Oct 1, 2015, at 10:26 AM, Allan Sindelar <<a href="mailto:allan@sindelarsolar.com" target="_blank"></a><a href="mailto:allan@sindelarsolar.com" target="_blank">allan@sindelarsolar.com</a>>
wrote:</div>
<br>
<div>
<div style="background-color:rgb(255,255,255)" bgcolor="#FFFFFF" text="#000000"> Jerry,<br>
The five batteries aren't in series. I thought I made that
clear, but maybe not. Two are in parallel at 6V at the
positive end, and then that pair are in series with the
remaining three.<br>
Allan<br>
<br>
<div>
<div>
<p class="MsoNormal"><b>Allan Sindelar</b><br>
<span style="font-size:10.0pt"><a href="mailto:allan@sindelarsolar.com" target="_blank"></a><a href="mailto:allan@sindelarsolar.com" target="_blank">allan@sindelarsolar.com</a></span><br>
<span style="font-size:10.0pt">NABCEP
Certified PV Installation Professional<br>
NABCEP Certified Technical Sales Professional<br>
New Mexico EE98J Journeyman Electrician<br>
Founder (Retired), <span>Positive
Energy, Inc.</span><br>
<b><a href="tel:505%20780-2738" value="+15057802738" target="_blank">505 780-2738</a> cell</b><br>
<br>
<b><u></u><u></u></b></span></p>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
</div>
<div><br>
</div>
</div>
</div>
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