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<p>Hi Jason, I spoke with Solark re Homegrid and EG4. Did not
mention you name but your experience. You have been really
helpful. I am centering on open loop w EG4. My longest work
commute is 15 minutes on this island, so it's just having the time
to trouble shoot. Plus, one mess up, and everyone knows about it.
Chris</p>
<div class="moz-cite-prefix">On 9/3/2025 1:18 PM, Jason Szumlanski
via RE-wrenches wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAE438R_a7fT7ZbvYB56Wz9eguPytJMNoCNY9pN3y=R4L0F-KbA@mail.gmail.com">
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<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif">Nothing
like a coincidence... </div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif"><br>
</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif">A client on
an island with three stacks of 8 HomeGrid batteries has
just called me to report that the entire system is down.
All of the battery BMS module displays are dark. I have
mySolArk data from three inverters there that show the
batteries were topped off and just idling along with solar
covering the load at 5:00 pm last night when the power
suddenly went out, killing the Starlink connection. I'm
going for a boat ride tomorrow to check it out. Ugh. </div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif"><br>
</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif">I will
report my findings. Not sure if it's a battery or inverter
issue, but the customer's handyman reported nothing on the
battery screens, which seems strange to me. Even an error
should not turn the display off, as far as I recall.</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif"><br>
</div>
<div class="gmail_default"
style="font-family:arial,helvetica,sans-serif">P.S. No
power loss notifications from Sol-Ark is a
frustrating loss of functionality. I heard a rumor on
Facebook that they are fixing this in mySolArk this month,
but I'm not holding my breath.</div>
<br clear="all">
</div>
<div>
<div dir="ltr" class="gmail_signature">
<div dir="ltr"><br>
Jason Szumlanski
<div><span
style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">Principal
Solar Designer | Florida Solar Design Group</span><br
style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">
<span
style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">NABCEP
Certified Solar Professional (PVIP)</span><br
style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">
<span
style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">Florida
State Certified Solar Contractor CVC56956</span></div>
<div><font color="#333333"
face="Roboto, RobotoDraft, Helvetica, Arial, sans-serif">Florida
Certified Electrical Contractor EC13013208</font></div>
</div>
</div>
</div>
<br>
</div>
<br>
<div class="gmail_quote gmail_quote_container">
<div dir="ltr" class="gmail_attr">On Tue, Sep 2, 2025 at
4:31 PM Jason Szumlanski <<a
href="mailto:jason@floridasolardesigngroup.com"
moz-do-not-send="true" class="moz-txt-link-freetext">jason@floridasolardesigngroup.com</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote"
style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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<div>
<div style="font-family:arial,helvetica,sans-serif">We
have some stacks of HomeGrid out there in various
capacities, from the smallest with five in a stack,
up to four fully populated stacks of eight. In
total, I oversee around 150 Stack'd batteries,
including many that I installed and some that were
installed by others. I will say that they are easy
to install, have a nice bold visual interface, look
good, and perform up to expectations. They
communicate flawlessly with Sol-Ark 15k. However...</div>
<div style="font-family:arial,helvetica,sans-serif"><br>
</div>
<div style="font-family:arial,helvetica,sans-serif">I
believe there is a fundamental design flaw in this
stackable battery architecture. Here is why I am no
longer offering HomeGrid in a nutshell:</div>
<div>
<ul>
<li style="font-family:arial,helvetica,sans-serif">When
one battery in a stack has a fault, the entire
stack faults out, which renders the stack
non-functional until you either:</li>
<ol style="font-family:arial,helvetica,sans-serif">
<li>Remove the battery from the stack or turn
the circuit breaker off, and:</li>
<li>Reconfigure all of the dip switches to
remove the battery from the communication
loop, then:</li>
<li>Reprogram the master BMS to recognize the
new stack members and their positions.</li>
</ol>
<li style="font-family:arial,helvetica,sans-serif">If
you have multiple stacks, you have to do all of
the above, and in addition:</li>
<ol style="font-family:arial,helvetica,sans-serif">
<li>Remove a battery from each additional stack
to balance them, then perform all of the above
steps on each stack. </li>
<li>But before you reprogram each master BMS you
have to take the stacks out of
parallel communication, then reprogram the
parallel stacks before operation again. </li>
<li>Making each stack equal is per HomeGrid
support, but in practice, I don't know if it
is necessary, especially if you are losing one
of eight (12.5%). If you have smaller stacks,
this might be a bigger issue.</li>
</ol>
<li><font face="arial, helvetica, sans-serif">To
diagnose a battery issue with a laptop and
cable and get warranty support, you can only
do that with the master BMS because each
battery does not have a comm port. That means
you have to have the entire stack
non-functional while you perform diagnostics,
which is not ideal for off-grid settings,
especially if there is only one stack.</font></li>
<li><font face="arial, helvetica, sans-serif">If a
battery fails to balance and becomes depleted,
causing </font>a fault, there are no simple
terminal bolts to connect an external charger.
I'm not sure how you would even accomplish a
manual charge without opening up the case.</li>
</ul>
</div>
<div style="font-family:arial,helvetica,sans-serif">The
EG4 server rack batteries work in a fundamentally
different way. Each battery has an independent BMS.
When there is an alarm in a stack or stacks of
batteries, the entire battery bank does not fault
out. You can physically take a battery out of the
stack without changing any dip switches on the other
batteries. You can shut one down or experience
a fault on one battery without any others shutting
down. I have tried this with the LifePower4
batteries, even when there are multiple
communication strings of 16 batteries connected to a
communication hub. The rest of the batteries just
keep on working, which is the way it should be! The
communication hub will just show zero values for the
battery that is missing from the stack. I cannot
confirm if this is the case with the LL batteries,
but I suspect it would be. In a way, this is like
having the batteries in an open loop in terms of
resilience, with all of the benefits that
closed-loop battery communications offers. I have
had a small variety of battery issues with EG4, and
not once has the whole bank of batteries been
affected by one battery's issue.</div>
<div style="font-family:arial,helvetica,sans-serif"><br>
</div>
<div style="font-family:arial,helvetica,sans-serif">Side
note about another server rack option: I can confirm
that Pytes Ebox V1 batteries in a
communication stack will shut down all batteries if
one has a fault, at least confirmed by one situation
I had. This is despite each battery having it's own
BMS and console port to communicate with the
batteries. The situation in my case was a battery
that had no "Barcode" programmed into it, which was
causing a parallel communication fault and shutting
down the whole stack. In this case, physically
bypassing the battery with the issue with a Cat5
coupling worked fine. There are no dip switches to
set, and the master battery reconfigures the
communication stack automatically. With Pytes'
support, I was able to manually code in the Barcode
to the BMS with a console cable, and the problem
went away. I am not sure if all varieties of faults
would have the same effect with Pytes EBoxes, but
this communication issue definitely caused the whole
stack to fault out.</div>
<div style="font-family:arial,helvetica,sans-serif"><br>
</div>
<div style="font-family:arial,helvetica,sans-serif"><br>
</div>
<div style="font-family:arial,helvetica,sans-serif">The
phenomenon of the new breed of LFP batteries lacking
reliability/redundancy inspired a blog post that I
did just a couple of weeks ago: <a
href="https://floridasolardesigngroup.com/homegrid-stackd-batteries-the-redundancy-fallacy"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">https://floridasolardesigngroup.com/homegrid-stackd-batteries-the-redundancy-fallacy</a></div>
</div>
<div><br>
</div>
<div><br>
</div>
<div>
<div style="font-family:arial,helvetica,sans-serif">A
couple of other notes on HomeGrid:</div>
<div style="font-family:arial,helvetica,sans-serif">
<ul>
<li>They do not have any way to connect conduit to
the BMS. You wouldn't want to anyway, especially
with rigid conduit, since you might need to
remove the BMS for service. The BMS should be at
the bottom, in my opinion, for this reason. You
can only run positive and negative battery
cables out of the provided strain relief glands
in free air, and it requires that the batteries
be about 4 inches away from the wall. There is
no suitable way to protect 100% of the battery
cables.</li>
<li>Along the same lines, if you ever plan to
expand the system, make sure you leave enough
battery cable length to reach a higher level.</li>
<li>The lack of busbars is a really nice feature
(until you get into larger systems).</li>
<li>The discharge rate supports the maximum input
for a Sol-Ark 15K with, I believe, just three
batteries.</li>
<li>I love their "busbar pair" designed
specifically for the Sol-Ark 15K. I order a pair
with every inverter, regardless of what battery
I am using (although I am not actively selling
Sol-Ark right now).</li>
<li>You can't monitor the condition of
individual batteries with Solar Assistant, or
any other tool remotely to my knowledge. You
can't even monitor the condition of paralleled
stacks.</li>
<li>The "app" for the batteries is mind-bendingly
useless – unless I'm really missing something.</li>
<li>For some firmware and hardware versions,
over-the-air updates are not possible, and
HomeGrid will need to send you an update tool.
To be fair, I think this is also the case with
EG4 and some other manufacturers.</li>
<li>Once we received a shipment where three of
eight batteries were in the right boxes, but
there were no guts in the batteries at all! It
was just an empty steel battery shell. We had to
send them back to our supplier. The boxes
actually said 13 Kg on the labels rather than 52
Kg, but nobody at the factory caught it.
Strange.</li>
<li>HomeGrid Support is very competent, I would
say among the best in terms of knowing
their products inside and out, but it's 50/50
whether I get someone on the phone or get a call
back in a timely manner that allows me to
complete a service call. They are willing to
schedule assistance if you have an off-grid
situation that requires help.</li>
</ul>
</div>
<br>
</div>
<div>
<div style="font-family:arial,helvetica,sans-serif">Is
this a vote for EG4? Not necessarily, but it's hard
to argue with the price and the superior
reliability/redundancy aspects of the LifePower4/LL
batteries. One battery fault should not shut down an
entire system unless there is a legitimate safety
hazard. It's possible that these are UL issues
that require system shutdowns, but EG4 appears to
have overcome the problems I've seen with other
manufacturers' products.</div>
<div style="font-family:arial,helvetica,sans-serif"><br>
</div>
<div style="font-family:arial,helvetica,sans-serif">Like
others mentioned, I prefer to go with the 14.3 kWh /
16 kWh sealed batteries. I feel they have better
build quality (other than my recent rant about rust
on the MNP PowerFlo16), and keeping components
sealed up better just makes sense to me, especially
in challenging environments. Of course, if you want
more modularity in terms of expansion options and
less impact if a single unit goes down, 5 kWh units
might be a better option. There is no right or wrong
option, I guess – sometimes it just comes down to
priorities, space, mounting options, and price. </div>
<br>
</div>
<div>
<div dir="ltr" class="gmail_signature">
<div dir="ltr"><br>
Jason Szumlanski
<div><span
style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">Principal
Solar Designer | Florida Solar Design Group</span><br
style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">
<span
style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">NABCEP
Certified Solar Professional (PVIP)</span><br
style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">
<span
style="color:rgb(51,51,51);font-family:Roboto,RobotoDraft,Helvetica,Arial,sans-serif;font-size:13px">Florida
State Certified Solar Contractor CVC56956</span></div>
<div><font color="#333333"
face="Roboto, RobotoDraft, Helvetica, Arial, sans-serif">Florida
Certified Electrical Contractor EC13013208</font></div>
</div>
</div>
</div>
<br>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Tue, Sep 2, 2025 at
10:41 AM Christopher Warfel via RE-wrenches <<a
href="mailto:re-wrenches@lists.re-wrenches.org"
target="_blank" moz-do-not-send="true"
class="moz-txt-link-freetext">re-wrenches@lists.re-wrenches.org</a>>
wrote:<br>
</div>
<blockquote class="gmail_quote"
style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi
Wrenches, I went through the archives and read the
comparison between <br>
these two. The HomeGrid manual was in such a mess (or
my pdf reader was <br>
defunct), that I started looking at other options. If
anyone has a <br>
strong opinion of either of these two, or something
better, I would <br>
appreciate. We traditionally install small systems,
and this would be <br>
one (@15kWh). I would prefer to use a racking system
with the BMS as <br>
part of the packaging. Solark 12kPV multimode. Thank
you, Chris<br>
<br>
-- <br>
Christopher Warfel, PE<br>
ENTECH Engineering, Inc.<br>
PO Box 871, Block Island, RI 02807<br>
(401) 447-5773<br>
<br>
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<pre class="moz-signature" cols="72">--
Christopher Warfel, PE
ENTECH Engineering, Inc.
PO Box 871, Block Island, RI 02807
(401) 447-5773</pre>
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