[RE-wrenches] EG4 v HomeGrid battery systems update?
Ray Walters
ray at solarray.com
Thu Sep 4 18:42:03 PDT 2025
Hi Maverick;
The system used a Victron 1200 VA Phoenix Inverter, open loop with
voltage set points. All of this fairly new to me, using blue tooth to
program the inverter, having to have a hot spot to provide internet. I
even recently had to buy a budget PC laptop, since I had Macs, which are
not compatible with any of this Chinese equipment. Including the DC
power supply to dark start these things, I've got a $1000 in special
tools to service LiPO4.
After decades of great service from Trace, Outback, Magnum, and Midnite,
I can't wait to retire with all these new head aches related to firmware
mismatch, etc. I assume an AI robot will be replacing me in a couple of
years.
Ray
On 9/3/2025 3:12 PM, Maverick Brown via RE-wrenches wrote:
> This brings me back to a question I was trying to get data on…
>
> Not just specific to HomeGrid, but what Inverter was being used in
> this case? Was it open loop or closed loop? If open loop, was it
> inverter driven % based or inverter driven Voltage based?
>
> Recently, I had a long intermittent technical issue with a pair of
> Sol-Ark inverters that was using open loop but percentage based and it
> kept crashing out because the Simpliphi Battery BMS was at zero SOC
> when the inverter thought there was something left.
>
> I added a Victron SmartShunt to monitor and found that Inverter
> Percentage was not charging to the proper voltage (high enough to fill
> all the batteries). I switched to Voltage control and now all is well.
> Even the chart data on the inverter would show low voltage situations
> and would explain the situation. I just hadn’t even looked at the data
> deeply enough.
>
> I wonder if Percent Closed Loop control is better than Percent Open
> Loop control or are we leaving energy on the table?
>
> Let me know what you think?
>
> Maverick
>
> Maverick Brown
> Off-Grid Solar Commander since 2006
> *Maverick Solar Enterprises, Inc.*
> * • Solar Commander Remote Power*
> * • SunFlow Systems Cathodic Protection
> *maverick at mavericksolar.com
> 512-460-9825
>
>> On Sep 3, 2025, at 3:55 PM, Ray Walters via RE-wrenches
>> <re-wrenches at lists.re-wrenches.org> wrote:
>>
>> I have one Home Grid system out here; its in their outdoor enclosure
>> with built in battery heating. I've had more call backs in the past
>> year with that system than all my other off grid systems combined.
>> I've struggled with getting the right LVD settings, and even with
>> decent settings, it seems the battery heating and the no load draw of
>> the BMS will go ahead and drag the battery into shut down, requiring
>> a trip out. I have a small variable DC power supply which has been
>> very important in the new days of LiPO4. I run it on a Ryobi inverter.
>>
>> One of the times I went out, the system was not shut down, but the
>> HomeGrid screen was blank, and I had to reboot the battery to get it
>> back on. I also experienced the BMS shutdown others mentioned, when
>> one of the 4 batteries was out of EQ with the other batteries. Even
>> the initial startup was a nightmare, requiring a tech to take over my
>> computer remotely, and then a month later, I had to sit out there for
>> 3 hours while it came to full charge so I could bring the 4th battery
>> back on line. At least their Tech Support was really good.
>>
>> Also their outdoor enclosure is really chinzy, it takes over 30
>> stainless screws to attach the 2 halves together, and many of those
>> screws have galled and are unusable. I even had to cut a couple off
>> just to get in to service the battery.
>>
>> Ray
>> Remote Solar
>>
>> On 9/3/2025 11:18 AM, Jason Szumlanski via RE-wrenches wrote:
>>> Nothing like a coincidence...
>>>
>>> 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.
>>>
>>> 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.
>>>
>>> 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.
>>>
>>>
>>> Jason Szumlanski
>>> Principal Solar Designer | Florida Solar Design Group
>>> NABCEP Certified Solar Professional (PVIP)
>>> Florida State Certified Solar Contractor CVC56956
>>> Florida Certified Electrical Contractor EC13013208
>>>
>>>
>>> On Tue, Sep 2, 2025 at 4:31 PM Jason Szumlanski
>>> <jason at floridasolardesigngroup.com> wrote:
>>>
>>> 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...
>>>
>>> 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:
>>>
>>> * When one battery in a stack has a fault, the entire stack
>>> faults out, which renders the stack non-functional until you
>>> either:
>>> 1. Remove the battery from the stack or turn the circuit
>>> breaker off, and:
>>> 2. Reconfigure all of the dip switches to remove the
>>> battery from the communication loop, then:
>>> 3. Reprogram the master BMS to recognize the new stack
>>> members and their positions.
>>> * If you have multiple stacks, you have to do all of the
>>> above, and in addition:
>>> 1. Remove a battery from each additional stack to balance
>>> them, then perform all of the above steps on each stack.
>>> 2. 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.
>>> 3. 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.
>>> * 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.
>>> * If a battery fails to balance and becomes depleted, causing
>>> 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.
>>>
>>> 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.
>>>
>>> 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.
>>>
>>>
>>> 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:
>>> https://floridasolardesigngroup.com/homegrid-stackd-batteries-the-redundancy-fallacy
>>>
>>>
>>> A couple of other notes on HomeGrid:
>>>
>>> * 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.
>>> * 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.
>>> * The lack of busbars is a really nice feature (until you get
>>> into larger systems).
>>> * The discharge rate supports the maximum input for a Sol-Ark
>>> 15K with, I believe, just three batteries.
>>> * 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).
>>> * 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.
>>> * The "app" for the batteries is mind-bendingly useless –
>>> unless I'm really missing something.
>>> * 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.
>>> * 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.
>>> * 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.
>>>
>>>
>>> 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.
>>>
>>> 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.
>>>
>>>
>>> Jason Szumlanski
>>> Principal Solar Designer | Florida Solar Design Group
>>> NABCEP Certified Solar Professional (PVIP)
>>> Florida State Certified Solar Contractor CVC56956
>>> Florida Certified Electrical Contractor EC13013208
>>>
>>>
>>> On Tue, Sep 2, 2025 at 10:41 AM Christopher Warfel via
>>> RE-wrenches <re-wrenches at lists.re-wrenches.org> wrote:
>>>
>>> Hi Wrenches, I went through the archives and read the
>>> comparison between
>>> these two. The HomeGrid manual was in such a mess (or my
>>> pdf reader was
>>> defunct), that I started looking at other options. If anyone
>>> has a
>>> strong opinion of either of these two, or something better,
>>> I would
>>> appreciate. We traditionally install small systems, and
>>> this would be
>>> one (@15kWh). I would prefer to use a racking system with
>>> the BMS as
>>> part of the packaging. Solark 12kPV multimode. Thank you, Chris
>>>
>>> --
>>> Christopher Warfel, PE
>>> ENTECH Engineering, Inc.
>>> PO Box 871, Block Island, RI 02807
>>> (401) 447-5773
>>>
>>> _______________________________________________
>>> List sponsored by Redwood Alliance
>>>
>>> Pay optional member dues here: http://re-wrenches.org
>>>
>>> List Address: RE-wrenches at lists.re-wrenches.org
>>>
>>> Change listserver email address & settings:
>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>>
>>> There are two list archives for searching. When one doesn't
>>> work, try the other:
>>> https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
>>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>>>
>>> List rules & etiquette:
>>> http://www.re-wrenches.org/etiquette.htm
>>>
>>> Check out or update participant bios:
>>> http://www.members.re-wrenches.org
>>>
>>>
>>> _______________________________________________
>>> List sponsored by Redwood Alliance
>>>
>>> Pay optional member dues here:http://re-wrenches.org
>>>
>>> List Address:RE-wrenches at lists.re-wrenches.org
>>>
>>> Change listserver email address & settings:
>>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>>
>>> There are two list archives for searching. When one doesn't work, try the other:
>>> https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
>>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>>>
>>> List rules & etiquette:
>>> http://www.re-wrenches.org/etiquette.htm
>>>
>>> Check out or update participant bios:
>>> http://www.members.re-wrenches.org
>>>
>> _______________________________________________
>> List sponsored by Redwood Alliance
>>
>> Pay optional member dues here: http://re-wrenches.org
>>
>> List Address: RE-wrenches at lists.re-wrenches.org
>>
>> Change listserver email address & settings:
>> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>>
>> There are two list archives for searching. When one doesn't work, try
>> the other:
>> https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
>> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>>
>> List rules & etiquette:
>> http://www.re-wrenches.org/etiquette.htm
>>
>> Check out or update participant bios:
>> http://www.members.re-wrenches.org
>>
>
>
> _______________________________________________
> List sponsored by Redwood Alliance
>
> Pay optional member dues here:http://re-wrenches.org
>
> List Address:RE-wrenches at lists.re-wrenches.org
>
> Change listserver email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> There are two list archives for searching. When one doesn't work, try the other:
> https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/
> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
> List rules & etiquette:
> http://www.re-wrenches.org/etiquette.htm
>
> Check out or update participant bios:
> http://www.members.re-wrenches.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20250904/88170652/attachment.htm>
More information about the RE-wrenches
mailing list