<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=Content-Type content="text/html; charset=utf-8">
<META content="MSHTML 6.00.2900.6550" name=GENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=#ffffff>
<DIV>Hey Jay,</DIV>
<DIV> </DIV>
<DIV> From what I've heard form battery
manus, the C rates likely even in a well PV-ed system still will not
produce C-rates high enough to approach a high or "longevity reducing" internal
battery temp, assuming a typical bulk, absorb, float cycle. Of course,
battery environmental location (typical temps) would set a baseline from which
batt temp would rise from. Here in the Sierra, ambients are not very high
95% of the time.</DIV>
<DIV> </DIV>
<DIV> Just curious, how does the wiz bang
account for all loads...2 shunts?</DIV>
<DIV> </DIV>
<DIV>Thanks,</DIV>
<DIV> </DIV>
<DIV>Bill</DIV>
<DIV>Feather River Solar Electric</DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=jay.peltz@gmail.com href="mailto:jay.peltz@gmail.com">jay peltz</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=re-wrenches@lists.re-wrenches.org
href="mailto:re-wrenches@lists.re-wrenches.org">RE-wrenches</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, May 21, 2015 8:07
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [RE-wrenches] FLA battery
setpoints with larger arrays</DIV>
<DIV><BR></DIV>
<DIV dir=ltr>Hi Allan,
<DIV><BR></DIV>
<DIV>I like the classic/wiz bang jr. This allows really good end amp
control as all loads are accounted for.</DIV>
<DIV><BR></DIV>
<DIV>Higher C rates equal higher internal temps which definitely will shorten
the life.<BR>
<DIV class=gmail_extra><BR>
<DIV class=gmail_quote>On Thu, May 21, 2015 at 10:56 AM, 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="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">
<DIV style="COLOR: rgb(0,0,0); BACKGROUND-COLOR: rgb(255,255,255)"
text="#000000" bgcolor="#FFFFFF">Wrenches,<BR>In the last few years I have
changed my approach to off grid system sizing, primarily due to higher
battery costs and lower module costs. Rather than shooting for a traditional
80-90% of winter load profile target, I will size a larger array and smaller
battery bank, figuring (especially here in the sunny Southwest) that
batteries will recharge more quickly, will spend more of their time full
(and thus last longer), and will be at least partially charged during cloudy
weather. This even allows for smaller battery banks that are cycled more
deeply (as long as there's a backup gennie in the mix); the lower cost of a
smaller size may allow for a set of higher-quality industrial
cells.<BR><BR>I first began to rethink my design approach after reading
Christopher Freitas' Solar Pro article on large battery banks a few years
ago. Being able to refill in a day was part of his strategic approach to
battery bank design. I used and wrote about this approach in my tiny house
article in the current Home Power. However, I'm just beginning to get owner
feedback about greater water consumption and the need for more frequent
watering. This is especially the case when I add array to an existing
system, and the old watering schedule is suddenly not enough. <BR><BR>When I
design new systems I now encourage larger arrays and smaller battery banks,
as the batteries spend more of their time happily full and recover more
quickly after a discharge period. But I am thinking that I will have to
begin changing charging setpoints in response. Flooded batteries have a
range of recommended bulk setpoints, from 28.8 to 29.6 volts on a 24V
system. When arrays were smaller we set to the higher end of the range to
take advantage of topping off when available, and a two hour or longer
absorption was considered beneficial, as long as the CC could transition to
float at 2% of capacity or so. With a larger array a better approach may be
to lower the bulk/absorption setting, as well as reduce absorption time and
raise the float transition current ("done amps"). <BR><BR>I'm writing to
encourage a discussion among off grid Wrenches. Are you changing the
relative relationship between array and battery capacities? If so, how are
you adjusting charge controller setpoint programming? For example, how would
you program a Midnite Classic, Outback FM or Schneider XW if you could
achieve a C/10 or C/15 charge rate?<BR><BR>Thanks, Allan<SPAN
class=HOEnZb><FONT color=#888888><BR>
<DIV>
<DIV>
<P class=MsoNormal><B>Allan Sindelar</B><BR><SPAN style="FONT-SIZE: 10pt"><A
href="mailto:allan@sindelarsolar.com"
target=_blank>allan@sindelarsolar.com</A></SPAN><BR><SPAN
style="FONT-SIZE: 10pt">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" target=_blank
value="+15057802738">505 780-2738</A>
cell</B><BR><BR><B><U></U><U></U></B></SPAN></P>
<P
class=MsoNormal><U></U><U></U><BR> </P></DIV></DIV></FONT></SPAN></DIV></BLOCKQUOTE></DIV>
<DIV><BR></DIV>-- <BR>
<DIV class=gmail_signature>
<DIV dir=ltr>
<DIV>
<DIV dir=ltr>
<DIV>Jay Peltz<BR>Peltz Power<BR><A href="mailto:jay.peltz@gmail.com"
target=_blank>jay.peltz@gmail.com</A></DIV></DIV></DIV></DIV></DIV></DIV></DIV></DIV>
<P>
<HR>
<P></P>_______________________________________________<BR>List sponsored by
Redwood Alliance<BR><BR>List Address:
RE-wrenches@lists.re-wrenches.org<BR><BR>Change listserver email address &
settings:<BR>http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org<BR><BR>List-Archive:
http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html<BR><BR>List
rules & etiquette:<BR>www.re-wrenches.org/etiquette.htm<BR><BR>Check out
or update participant
bios:<BR>www.members.re-wrenches.org<BR><BR></BLOCKQUOTE></BODY></HTML>