<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></head><body><div>Wrenches, Drake</div><div>You may consider contacting "Batcap" and bank if they have a best practice for the battery configuration, this might be it but at least a starting point. I have had multi string batteries that seamed to like being rotated through the bank, sounds like alot of work and it is but this will swap higher resistance strings for lower ones. I'm sure you know this but each battery has internal resistance to charge and even discharge so rotating them reduces the effect and may in time help to improve the battery life. </div><div>Jerry</div><div><br></div><div><br></div><div><br></div><div id="composer_signature"><div style="font-size:85%;color:#575757" dir="auto">Sent from my Verizon, Samsung Galaxy smartphone</div></div><div><br></div><div style="font-size:100%;color:#000000"><!-- originalMessage --><div>-------- Original message --------</div><div>From: Drake <drake.chamberlin@redwoodalliance.org> </div><div>Date: 11/20/18 8:41 AM (GMT-08:00) </div><div>To: RE-wrenches <re-wrenches@lists.re-wrenches.org> </div><div>Subject: [RE-wrenches] Batt Cap AGM </div><div><br></div></div>
Hello Wrenches,<br><br>
An owner of an existing system has a bank of twenty, 100 AH, 12 V Deep
cycle batteries of the
<a href="http://www.xstaticbatcap.com/what-is-a-batcap-.html">Batcap</a>
<a href="http://www.xstaticbatcap.com/what-is-a-batcap-.html">
</a>brand.<br><br>
The bank is made up of four sets of 5 batteries in parallel to produce
<b>500 AH battery sets at 12 V.</b> These four parallel sets are then
wired in series to give a 48 V nominal bank. <br><br>
The battery voltages vary from around 13 to 15 volts. The bank is about 5
years old. The CEO of Batcap told the system owner that these batteries
have lasted up to 30 years in solar applications, so he has high
expectations for these batteries being around for a while. <br><br>
My first impulse is to rewire the bank in a normal series - parallel
configuration. But there are too many strings to do this without a bus
bar. Besides, the batteries are likely damaged, and rewiring them might
cause the bank to exhibit unsuspected problems. How much money is worth
putting into this bank? $0?<br><br>
The owner seems like a reliable guy who likely hired the wrong installer.
He could use some help. What would you do in this situation? Rewire the
bank, leave it well enough alone or run for the hills.<br><br>
Thanks,<br><br>
Drake <br><br>
<a name="_MailAutoSig"></a>Drake Chamberlin<br>
<i>Athens Electric LLC<br>
OH License 44810<br>
CO License 3773<br>
NABCEP Certified Solar PV <br>
740-448-7328<br>
</i><a href="http://athens-electric.com/">http://athens-electric.com/</a>
<br>
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