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Jerry,<br>
<br>
No doubt about it lithium battery chemistry is more efficient than
lead-acid battery chemistry. That is a good reason to choose lithium
batteries. However, 98% RTE is wrong. While being charged the
terminal voltage for lithium iron phosphate batteries, in a 48-volt
system, is typically 54.4 volts. While being discharged at light
load the terminal voltage is about 51 volts; it is even lower if
being discharged rapidly. The RTE efficiency cannot be greater than
51/54.4 or 94% and typically it will be even lower than that. Many
battery manufacturers claim over 95% RTE but that is only possible
when the battery doesn't go through a full discharge cycle. There
are many sources on the internet that say 98 or 99%, but that is
wrong, among us let's get it right.<br>
<br>
Kent Osterberg<br>
Blue Mountain Solar<br>
<br>
<br>
<div class="moz-cite-prefix">On 3/20/2021 7:01 PM, Jerry Shafer
wrote:<br>
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cite="mid:CAMUFgmU00C6CJ=TxJGbadYMhu=GjeaxzTHEa72Q0FWX+VadR_Q@mail.gmail.com">
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<div dir="auto">Wrenches
<div dir="auto">So what l got from the question is why when my
batteries are at 100% isn't everything just passing through.
Well, your batteries may be the issue, l stopped using AGM
batteries because of what l called spill over, the batteries
are never full and are leaking out as they are getting full.
This can just be loss because of the chemical reaction and the
electrons, even waist heat. AGM might have a RTE of 82% (round
trip efficiency) so some battery storage energy is lost to the
cosmos. Lithium ion phosphate can have a RTE of 98%, lead acid
75% Edison batterys maybe 60%. So what l am getting at is
different batteries have different losses internally, AGM's
are cheaper then some so you pick your efficiencies and
losses, a solution may be to fatten up the array to compensate
for the storage losses. I am sure someone may have an
alternate solution</div>
<div dir="auto">Jerry</div>
<div dir="auto">NABCEP PV Inspector </div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Fri, Mar 19, 2021, 9:49 AM
Christopher Warfel <<a
href="mailto:cwarfel@entech-engineering.com"
moz-do-not-send="true">cwarfel@entech-engineering.com</a>>
wrote:<br>
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<div>I have not been able to find a way to set my customers
battery charging parameters so that the AGM batteries do
not consume less of the pv output to maintain charge.
Here is an Optics view of the situation with a small image
embedded. (If you can answer, please remove image per Mr.
Welch's request.</div>
<div><br>
</div>
<div>I have the absorb voltage at 54.3 for one hour, the
float voltageat 54, the equalize at 56 (disabled for this
battery type).</div>
<div><br>
</div>
<div>It seems like this is a lot of energy being used by the
batteries, but I am hoping that some one with more
experience in these settings can weigh in on any changes I
should make, or if this is just how it is. Thank you,
Chris<br>
</div>
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<div><img
src="cid:part1.D223CA1F.E9663A89@entech-engineering.com"
alt="" moz-do-not-send="true" width="929" height="522"></div>
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<div>-- <br>
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<div>
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<div>
<div> <font face="PMingLiU-ExtB">
Christopher Warfel</font><br>
<font face="PMingLiU-ExtB">
ENTECH Engineering, Inc.</font><br>
<font face="PMingLiU-ExtB">PO Box 871, Block
Island, RI 02807</font><br>
<font face="PMingLiU-ExtB">
401-466-8978</font><br>
<font face="PMingLiU-ExtB"><a
href="http://entech-engineering.com"
target="_blank" rel="noreferrer"
moz-do-not-send="true"><img
src="cid:part2.800D1699.83918CBC@entech-engineering.com"
alt="" moz-do-not-send="true" width="274"
height="121" border="0"></a><br>
</font><br>
<br>
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