AllanI have been involved in off grid since the late 70's, l guess l have
picked up a thing or two. As batteries age most will require higher voltage to
reach the same specific gravity and will have a lower voltage under a load.
This is the result of resistance with in the battery. This battery may still be
good and just needs a good charge to get it back to a more normal state.The
entire wire harness from where it leaves the point of charge has it's own
resistance e, every connection, cable end, wire all of it has resistance and
measuring this is not as easy as you may think, you need to put a preset load
on the bank measure the complete circuit voltage, now do the same under charge,
measure each battery note everything and once done with all the seperate banks
you can see where the higher resistance is. This is why making all the cables
the same length and same size, l have seen some cables soldered to reduce
resistance. This in a long round about reason is why fewer bigger banks is
better then more smaller batteries. I can continue but you should be up to
speed nowJerrySent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Sindelar Solar
<al...@sindelarsolar.com> Date: 11/21/18 11:54 AM (GMT-08:00) To:
re-wrenches@lists.re-wrenches.org Subject: Re: [RE-wrenches] Batt Cap AGM
Jerry,
You write "I'm sure you know this..." but I don't know it. I
don't think I have heard this before, as you have presented it.
How do you rotate strings? Where did you learn this? Is there an
online source that you can provide?
Thanks, Allan
On 11/20/2018 6:21 PM, jerrysgarage01
wrote:
Wrenches, Drake
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.
Jerry
Sent from my
Verizon, Samsung Galaxy smartphone
-------- Original message --------
From: Drake <drake.chamber...@redwoodalliance.org>
Date: 11/20/18 8:41 AM (GMT-08:00)
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Subject: [RE-wrenches] Batt Cap AGM
Hello Wrenches,
An owner of an existing system has a bank of twenty, 100 AH, 12 V
Deep
cycle batteries of the
Batcap
brand.
The bank is made up of four sets of 5 batteries in parallel to
produce
500 AH battery sets at 12 V. These four parallel sets are
then
wired in series to give a 48 V nominal bank.
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.
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?
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.
Thanks,
Drake
Drake Chamberlin
Athens Electric LLC
OH License 44810
CO License 3773
NABCEP Certified Solar PV
740-448-7328
http://athens-electric.com/
_______________________________________________
List sponsored by Redwood Alliance
List Address: RE-wrenches@lists.re-wrenches.org
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive:
http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
www.members.re-wrenches.org
--
<!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;
mso-font-charset:0;
mso-generic-font-family:roman;
mso-font-pitch:variable;
mso-font-signature:-536870145 1107305727 0 0 415 0;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;
mso-font-charset:0;
mso-generic-font-family:swiss;
mso-font-pitch:variable;
mso-font-signature:-536870145 1073786111 1 0 415 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{mso-style-unhide:no;
mso-style-qformat:yes;
mso-style-parent:"";
margin-top:0in;
margin-right:0in;
margin-bottom:8.0pt;
margin-left:0in;
line-height:107%;
mso-pagination:widow-orphan;
font-size:11.0pt;
font-family:"Calibri",sans-serif;
mso-ascii-font-family:Calibri;
mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:Calibri;
mso-fareast-theme-font:minor-latin;
mso-hansi-font-family:Calibri;
mso-hansi-theme-font:minor-latin;
mso-bidi-font-family:"Times New Roman";
mso-bidi-theme-font:minor-bidi;}
a:link, span.MsoHyperlink
{mso-style-noshow:yes;
mso-style-priority:99;
color:blue;
text-decoration:underline;
text-underline:single;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-noshow:yes;
mso-style-priority:99;
color:#954F72;
mso-themecolor:followedhyperlink;
text-decoration:underline;
text-underline:single;}
span.GramE
{mso-style-name:"";
mso-gram-e:yes;}
.MsoChpDefault
{mso-style-type:export-only;
mso-default-props:yes;
font-family:"Calibri",sans-serif;
mso-ascii-font-family:Calibri;
mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:Calibri;
mso-fareast-theme-font:minor-latin;
mso-hansi-font-family:Calibri;
mso-hansi-theme-font:minor-latin;
mso-bidi-font-family:"Times New Roman";
mso-bidi-theme-font:minor-bidi;}
.MsoPapDefault
{mso-style-type:export-only;
margin-bottom:8.0pt;
line-height:107%;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;
mso-header-margin:.5in;
mso-footer-margin:.5in;
mso-paper-source:0;}
div.WordSection1
{page:WordSection1;}
-->
Allan Sindelar
al...@sindelarsolar.com
NABCEP Certified PV Installation
Professional
New Mexico EE98J Journeyman Electrician
Founder (Retired), Positive
Energy, Inc.
505 780-2738 cell
_______________________________________________
List sponsored by Redwood Alliance
List Address: RE-wrenches@lists.re-wrenches.org
Change listserver email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive:
http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out or update participant bios:
www.members.re-wrenches.org
