Re: [RE-wrenches] State of Charge Meter for Sol-Ark

[Kent via RE-wrenches]

William

This comment

   PS:  I am curious as to what you meant by: “At least with lithium
   batteries the SOC meter doesn't need to account for the return
   current dropping down as is required with lead-acid batteries.”

is regarding the two plus hours lead-acid batteries need for absorption 
time with constant voltage and decreasing charge current. Most lithium 
batteries need little or no absorption time. Get them to 54.4 volts (or 
whatever is specified) and in a few minutes they are done. That takes 
one variable out of the "full" calculation that coulomb counting SOC 
meters use for re-calibration to 100%.


Battery state of charge meters that are counting amphours are over 
simplifying things. A battery's full charge capacity, lithium or 
lead-acid, changes with temperature and (particularly with lead 
acid-batteries) with load. The full charge capacity is changing with 
age. It's complicated so we can't expect them to be perfect.


I also stopped using the Outback FNDC because it would reset to say 100% 
at inappropriate times. Spent lots of time collecting data to 
demonstrate the flaw to Outback; the FNDC is still operating with 
firmware 1.0. They don't get my business.


Without a SOC meter I've struggled with lithium batteries trying to find 
the right voltage to start the generator. Don't want things shutting 
down. Do want to use a large fraction of battery capacity. But the 
voltage is so load dependent that it is hard to find the spot to start 
the generator.


Spring is about here!

Kent Osterberg
Blue Mountain Solar


On 2/10/2024 10:09 AM, William Miller via RE-wrenches wrote:

Kent:

You raise a good point. I am now trying to correlate voltage versus 
SOC versus battery current.


I do know that after the system shut down and with zero battery 
current (at rest condition) the battery voltage was 48 and the SOC was 
in the mid 50s. The event code was a low battery shutdown. 48 volts at 
rest should not be 50% SOC. It should read 0% or 10%, at most.


Fortress tech support opined that the SOC was out of calibration and I 
needed to charge to 54.4. I did so and the readings now make more 
sense and the generator will now auto start.


I’m pretty confident we had an error in SOC calibration but, per your 
point, it did not necessarily occur suddenly or at the moment in time 
I suspected.


Per the general subject of this thread I still think that SOC 
calibration errors are a real scenario. For SI systems this can have 
greater consequences than for systems not so dependent on SOC. I think 
we agree that any SOC reading should be treated with some skepticism.


Thanks for pointing out something I missed.

William Miller

PS:  I am curious as to what you meant by: “At least with lithium 
batteries the SOC meter doesn't need to account for the return current 
dropping down as is required with lead-acid batteries.”  I want to 
learn as much as I can about all available battery technology.


WM
Miller Solar.com
805-438-5600
www.millersolar.com 


On Fri, Feb 9, 2024 at 3:19 PM Kent via RE-wrenches 
 wrote:


William,

I think that the SOC determined by lithium BMSs come with similar
accuracy issues that occur with the Trimetric, FNDC, Magnum
BMK,... - small measurement errors integrated over a long time
become big errors. That's why Fortress (and every SOC meter) is
saying that the battery needs to reach 54.4 volts once a week for
recalibration. At least with lithium batteries the SOC meter
doesn't need to account for the return current dropping down as is
required with lead-acid batteries. The internal BMSs probably do a
better job of estimating the SOC than these external devices, but
I do not expect them to be perfect. Same goes with everyone's
electric car, while we put a lot of faith in the displayed SOC it
probably isn't much better than ±5% and if it were off by 10% you
probably wouldn't know.

In regards to your graph showing a big voltage difference between
two 55% SOC occurrences over a 12 hour time frame. I question your
assumption that the voltage  should be the same. The data show
different voltages for the same SOC, it seems unlikely that the
BMS measurement drifted by enough to make that happen, so I think
the data shown may both be correct within reason. The voltage of
lithium cells is highly load dependent (probably somewhat
temperature dependent too) so perhaps the Fortress battery is
actually close to right at both times.

Since using the SI SOC meter for starting the generator is
problematic, an external device for starting based on voltage is a
good idea.  If you want a ready to go product to do that, I think
the Morningstar relay driver will work well. A little difficult to
program or reprogram but very reliable. One issue you will observe
is that the generator won't start at a consistent SOC as indicated
by the battery 

Re: [RE-wrenches] State of Charge Meter for Sol-Ark

[Bruce Erickson via RE-wrenches]

William, I have had the same frustration with attempting to train customers to 
monitor voltage, and to treat SOC with suspicion. Some people are capable of 
getting it, some just aren’t. Off-grid life is tougher for those folks, and for 
their solar contractors. “I don’t understand why I lost power—the Trimetric 
says 75%!”  “Have you looked at at the voltage?”  “The what?”

Part of the problem is that we as consumers have been trained to believe the 
SOC numbers on our smart phones. I know I believe mine. We just got an electric 
car and same deal. Went on our first road trip, and of course had no choice but 
to manage charging based on the nice percent numbers on the screen. But in both 
cases, those devices seem to track battery state reasonably well. Too bad solar 
battery manus can’t do whatever Apple and Volkswagen et al can do.

Bruce Erickson
Mendocino Solar Service
707-937-1701 
PO Box 1252
Mendocino, CA 95460
 


"Serving the Solar System"





> On Feb 9, 2024, at 8:05 AM, Drake Chamberlin via RE-wrenches 
>  wrote:
> 
> How does the lack of accuracy in SOC detection affect the usefulness of 
> closed loop systems?
> 
>  
> Drake Chamberlin
> 
> Athens Electric LLC
> 
> Ohio Electrical Contractor’s License 44810
> 
> NABCEP Certified PV Installation Professional
> 
> 
> 
> On 2024-02-05 11:36, William Miller via RE-wrenches wrote:
> 
>> Jason:
>>  
>> I am careful about getting my clients too dependent on SOC readings.  SOC is 
>> a calculated value based on changing variables and is notoriously inaccurate.
>>  
>> Below is a screenshot of the Optics reporting for a client.  The graph line 
>> that begins as the lower of the two is the SOC, the other is voltage.  The 
>> SOC is out of calibration until about noon when it jumps from about 20% to 
>> about 80%.  This does not mean the SOC changed by that amount, it means that 
>> it was just very wrong.  Who knows when it is correct?
>>  
>> In spite of repeated entreaties this client still reads the SOC and becomes 
>> concerned when it gets low-- even if the voltage level indicates the 
>> batteries are well charged.  I have to deal with his misplaced anxiety.
>>  
>>  
>> 
>>  
>> This problem appears to occur across all battery/inverter technology.  For 
>> example, SMA touts their "coulomb counting" as more accurate than others but 
>> I have witnessed otherwise.  You'd think that BMS units built by lithium 
>> manufacturers for their own products would be consistently accurate but even 
>> those BMS units need to recalibrate frequently, this according to the 
>> battery manufacturer's engineers.
>>  
>> It would be nice to offer clients a simple, accurate method of ascertaining 
>> battery charge levels.  SOC is not that method.  I train my clients to watch 
>> voltage levels and to understand these values are elastic.  If you can see 
>> trends in the battery voltage, so much the better. This is why I like the 
>> Outback Optics interface.  This is also why a good AGS system examines 
>> battery voltage over time.
>>  
>> I no longer install Outback FNDC units.  Without them there is no SOC 
>> reading.  I don't install Sunny Island systems—they are SOC centered and 
>> suffer for it.
>>  
>> William
>>  
>> Miller Solar
>> 17395 Oak Road, Atascadero, CA 93422
>> 805-438-5600
>> www.millersolar.com <http://www.millersolar.com/>
>> CA Lic. 773985
>>  
>>  
>> From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org 
>> <mailto:re-wrenches-boun...@lists.re-wrenches.org>] On Behalf Of Jason 
>> Szumlanski via RE-wrenches
>> Sent: Sunday, February 4, 2024 7:30 AM
>> To: RE-wrenches
>> Cc: Jason Szumlanski
>> Subject: [RE-wrenches] State of Charge Meter for Sol-Ark
>>  
>> Are there any off the shelf solutions to view battery SOC via a wired meter 
>> mounted remotely on a property? I have a client with a simple voltage based 
>> meter for lead acid batteries that they are accustomed to using as a quick 
>> and approximate gauge of SOC. They want something similar for their new 
>> Sol-Ark with EG4 LL batteries. 
>>  
>> They will have smartphone app visibility, but they want something they can 
>> see inside the house without picking up a phone or going out to the 
>> inverter. Ideally the SOC will come from the inverter or the battery itself, 
>> not an external source (to avoid discrepancies).
>>  
>> Jason Szumlanski
>> Florida Solar Design Group 
>> 
>> ___
>> List sponsored by Redwo

Re: [RE-wrenches] State of Charge Meter for Sol-Ark

[Drake Chamberlin via RE-wrenches]

How does the lack of accuracy in SOC detection affect the usefulness of
closed loop systems? 

_Drake Chamberlin_ 

_Athens Electric LLC_ 

_Ohio Electrical Contractor's License 44810_ 

_NABCEP Certified PV Installation Professional_ 


On 2024-02-05 11:36, William Miller via RE-wrenches wrote:

Jason: 

I am careful about getting my clients too dependent on SOC readings.  SOC is a calculated value based on changing variables and is notoriously inaccurate. 

Below is a screenshot of the Optics reporting for a client.  The graph line that begins as the lower of the two is the SOC, the other is voltage.  The SOC is out of calibration until about noon when it jumps from about 20% to about 80%.  This does not mean the SOC changed by that amount, it means that it was just very wrong.  Who knows when it is correct? 

In spite of repeated entreaties this client still reads the SOC and becomes concerned when it gets low-- even if the voltage level indicates the batteries are well charged.  I have to deal with his misplaced anxiety. 

This problem appears to occur across all battery/inverter technology.  For example, SMA touts their "coulomb counting" as more accurate than others but I have witnessed otherwise.  You'd think that BMS units built by lithium manufacturers for their own products would be consistently accurate but even those BMS units need to recalibrate frequently, this according to the battery manufacturer's engineers. 

It would be nice to offer clients a simple, accurate method of ascertaining battery charge levels.  SOC is not that method.  I train my clients to watch voltage levels and to understand these values are elastic.  If you can see trends in the battery voltage, so much the better. This is why I like the Outback Optics interface.  This is also why a good AGS system examines battery voltage over time. 

I no longer install Outback FNDC units.  Without them there is no SOC reading.  I don't install Sunny Island systems--they are SOC centered and suffer for it. 

William 

Miller Solar 

17395 Oak Road, Atascadero, CA 93422 

805-438-5600 

www.millersolar.com [1] 

CA Lic. 773985 


From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf 
Of Jason Szumlanski via RE-wrenches
Sent: Sunday, February 4, 2024 7:30 AM
To: RE-wrenches
Cc: Jason Szumlanski
Subject: [RE-wrenches] State of Charge Meter for Sol-Ark 

Are there any off the shelf solutions to view battery SOC via a wired meter mounted remotely on a property? I have a client with a simple voltage based meter for lead acid batteries that they are accustomed to using as a quick and approximate gauge of SOC. They want something similar for their new Sol-Ark with EG4 LL batteries. 


They will have smartphone app visibility, but they want something they can see 
inside the house without picking up a phone or going out to the inverter. 
Ideally the SOC will come from the inverter or the battery itself, not an 
external source (to avoid discrepancies).

Jason Szumlanski 

Florida Solar Design Group  
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Links:
--
[1] http://www.millersolar.com/

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Re: [RE-wrenches] State of Charge Meter for Sol-Ark

[Mick Abraham via RE-wrenches]

Me again, Mechanics, with some corrections to my recent post. Solar
Assistant may not be a US based provider. They publish pricing in US
dollars but I was unable to log in or create an account.

Watts247.com claims to be the only authorized US distributor.

https://watts247.com/product/solar-assistant-remote-monitoring-mpp-solar-growatt-deye-sol-ark-sunsynk-and-many-bmss/

but their pricing pushes the system cost well above the cost for a
TriMetric. I apologize for uploading wrong/incomplete  information before,
thanks.

Mick Abraham, Proprietor
www.abrahamsolar.com

Landline: 970-731-4675
Cell phone or for text messaging: 970-946-6584
ᐧ
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Re: [RE-wrenches] State of Charge Meter for Sol-Ark

[Mick Abraham via RE-wrenches]

~ This is yet another worthwhile topic with the Mechanics ~

Chris Mason wrote:  "If you know someone who can set up a little raspberry
pi with a display, you try this script. It's called solark-modbus."

I did a google for Solark "raspberry pi" & the first link took me to this:
https://solar-assistant.io/explore/solark

For an amateur like me, getting the hardware and software from Solar
Assistant has a lot of appeal, even if it costs more than a home brew
setup. How 'bout that "single source accountability"?

Original poster Jason Szumlanski may appreciate the video that I've linked
below. The video creator connected a touch screen display directly to his
Solar Assistant box:

https://www.youtube.com/watch?v=wXOVVMOGfNM

I may try the S-A bundle with an EG4 battery for some off gridders in
crisis. Their old Outback system doesn't even have a TriMetric monitor, but
for about the same price as a TM-2020, we could get the SOC data, etc.
directly from the BMS. I'd use the client's computer instead of a touch
screen to keep the cost down. Acknowledged (to William Miller's point) the
data would be no better than what the BMS can deliver. "Any port in a
storm," however, and my new friends off the grid are in a terrible storm.

As always, "The Wrench List is the Bomb!"

Mick Abraham, Proprietor
www.abrahamsolar.com

Landline: 970-731-4675
Cell phone or for text messaging: 970-946-6584
ᐧ
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Re: [RE-wrenches] State of Charge Meter for Sol-Ark

[William Miller via RE-wrenches]

Jason:



EVs apparently have their own problems with metering:
https://www.caranddriver.com/news/a44754199/tesla-range-display-estimate-tested/



William





Miller Solar

17395 Oak Road, Atascadero, CA 93422

805-438-5600

www.millersolar.com

CA Lic. 773985





*From:* Jason Szumlanski [mailto:ja...@floridasolardesigngroup.com]
*Sent:* Monday, February 5, 2024 9:52 AM
*To:* William Miller
*Cc:* RE-wrenches
*Subject:* Re: [RE-wrenches] State of Charge Meter for Sol-Ark



This isn't an acceptable response that I can give to people spending tens
of thousands of dollars on batteries. These clients roll into their garage
and their EV tells them how many miles are left (state of charge,
effectively). If it can be done in an EV, it's unacceptable to resign
ourselves as solar professionals to tell clients there is no reasonably
accurate way estimate state of charge of a backup battery, which is based
on the same technology as an EV battery.



I have seen the "elasticity" of SOC reading you mentioned. It's just
unacceptable in this day and age. We need to demand better from the
manufacturers. Clients will be okay with some degree of uncertainty, but we
can't have a fuel gauge bouncing all over the place.



-end of rant-



Jason





On Mon, Feb 5, 2024, 11:51 AM William Miller 
wrote:

Jason:



I am careful about getting my clients too dependent on SOC readings.  SOC
is a calculated value based on changing variables and is notoriously
inaccurate.



Below is a screenshot of the Optics reporting for a client.  The graph line
that begins as the lower of the two is the SOC, the other is voltage.  The
SOC is out of calibration until about noon when it jumps from about 20% to
about 80%.  This does not mean the SOC changed by that amount, it means
that it was just very wrong.  Who knows when it is correct?



In spite of repeated entreaties this client still reads the SOC and becomes
concerned when it gets low-- even if the voltage level indicates the
batteries are well charged.  I have to deal with his misplaced anxiety.





[image: SOC][image: VDC]



This problem appears to occur across all battery/inverter technology.  For
example, SMA touts their “coulomb counting” as more accurate than others
but I have witnessed otherwise.  You’d think that BMS units built by
lithium manufacturers for their own products would be consistently accurate
but even those BMS units need to recalibrate frequently, this according to
the battery manufacturer’s engineers.



It would be nice to offer clients a simple, accurate method of ascertaining
battery charge levels.  SOC is not that method.  I train my clients to
watch voltage levels and to understand these values are elastic.  If you
can see trends in the battery voltage, so much the better. This is why I
like the Outback Optics interface.  This is also why a good AGS system
examines battery voltage over time.



I no longer install Outback FNDC units.  Without them there is no SOC
reading.  I don’t install Sunny Island systems—they are SOC centered and
suffer for it.



William



Miller Solar

17395 Oak Road, Atascadero, CA 93422

805-438-5600

www.millersolar.com

CA Lic. 773985





*From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On
Behalf Of *Jason Szumlanski via RE-wrenches
*Sent:* Sunday, February 4, 2024 7:30 AM
*To:* RE-wrenches
*Cc:* Jason Szumlanski
*Subject:* [RE-wrenches] State of Charge Meter for Sol-Ark



Are there any off the shelf solutions to view battery SOC via a wired meter
mounted remotely on a property? I have a client with a simple voltage based
meter for lead acid batteries that they are accustomed to using as a quick
and approximate gauge of SOC. They want something similar for their new
Sol-Ark with EG4 LL batteries.



They will have smartphone app visibility, but they want something they can
see inside the house without picking up a phone or going out to the
inverter. Ideally the SOC will come from the inverter or the battery
itself, not an external source (to avoid discrepancies).



Jason Szumlanski

Florida Solar Design Group
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Re: [RE-wrenches] State of Charge Meter for Sol-Ark

[Jason Szumlanski via RE-wrenches]

This isn't an acceptable response that I can give to people spending tens
of thousands of dollars on batteries. These clients roll into their garage
and their EV tells them how many miles are left (state of charge,
effectively). If it can be done in an EV, it's unacceptable to resign
ourselves as solar professionals to tell clients there is no reasonably
accurate way estimate state of charge of a backup battery, which is based
on the same technology as an EV battery.

I have seen the "elasticity" of SOC reading you mentioned. It's just
unacceptable in this day and age. We need to demand better from the
manufacturers. Clients will be okay with some degree of uncertainty, but we
can't have a fuel gauge bouncing all over the place.

-end of rant-

Jason


On Mon, Feb 5, 2024, 11:51 AM William Miller 
wrote:

> Jason:
>
>
>
> I am careful about getting my clients too dependent on SOC readings.  SOC
> is a calculated value based on changing variables and is notoriously
> inaccurate.
>
>
>
> Below is a screenshot of the Optics reporting for a client.  The graph
> line that begins as the lower of the two is the SOC, the other is voltage.
> The SOC is out of calibration until about noon when it jumps from about 20%
> to about 80%.  This does not mean the SOC changed by that amount, it means
> that it was just very wrong.  Who knows when it is correct?
>
>
>
> In spite of repeated entreaties this client still reads the SOC and
> becomes concerned when it gets low-- even if the voltage level indicates
> the batteries are well charged.  I have to deal with his misplaced anxiety.
>
>
>
>
>
> [image: SOC][image: VDC]
>
>
>
> This problem appears to occur across all battery/inverter technology.  For
> example, SMA touts their “coulomb counting” as more accurate than others
> but I have witnessed otherwise.  You’d think that BMS units built by
> lithium manufacturers for their own products would be consistently accurate
> but even those BMS units need to recalibrate frequently, this according to
> the battery manufacturer’s engineers.
>
>
>
> It would be nice to offer clients a simple, accurate method of
> ascertaining battery charge levels.  SOC is not that method.  I train my
> clients to watch voltage levels and to understand these values are
> elastic.  If you can see trends in the battery voltage, so much the better.
> This is why I like the Outback Optics interface.  This is also why a good
> AGS system examines battery voltage over time.
>
>
>
> I no longer install Outback FNDC units.  Without them there is no SOC
> reading.  I don’t install Sunny Island systems—they are SOC centered and
> suffer for it.
>
>
>
> William
>
>
>
> Miller Solar
>
> 17395 Oak Road, Atascadero, CA 93422
>
> 805-438-5600
>
> www.millersolar.com
>
> CA Lic. 773985
>
>
>
>
>
> *From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On
> Behalf Of *Jason Szumlanski via RE-wrenches
> *Sent:* Sunday, February 4, 2024 7:30 AM
> *To:* RE-wrenches
> *Cc:* Jason Szumlanski
> *Subject:* [RE-wrenches] State of Charge Meter for Sol-Ark
>
>
>
> Are there any off the shelf solutions to view battery SOC via a wired
> meter mounted remotely on a property? I have a client with a simple voltage
> based meter for lead acid batteries that they are accustomed to using as a
> quick and approximate gauge of SOC. They want something similar for their
> new Sol-Ark with EG4 LL batteries.
>
>
>
> They will have smartphone app visibility, but they want something they can
> see inside the house without picking up a phone or going out to the
> inverter. Ideally the SOC will come from the inverter or the battery
> itself, not an external source (to avoid discrepancies).
>
>
>
> Jason Szumlanski
>
> Florida Solar Design Group
>
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Re: [RE-wrenches] State of Charge Meter for Sol-Ark

[William Miller via RE-wrenches]

Jason:



I am careful about getting my clients too dependent on SOC readings.  SOC
is a calculated value based on changing variables and is notoriously
inaccurate.



Below is a screenshot of the Optics reporting for a client.  The graph line
that begins as the lower of the two is the SOC, the other is voltage.  The
SOC is out of calibration until about noon when it jumps from about 20% to
about 80%.  This does not mean the SOC changed by that amount, it means
that it was just very wrong.  Who knows when it is correct?



In spite of repeated entreaties this client still reads the SOC and becomes
concerned when it gets low-- even if the voltage level indicates the
batteries are well charged.  I have to deal with his misplaced anxiety.





[image: SOC][image: VDC]



This problem appears to occur across all battery/inverter technology.  For
example, SMA touts their “coulomb counting” as more accurate than others
but I have witnessed otherwise.  You’d think that BMS units built by
lithium manufacturers for their own products would be consistently accurate
but even those BMS units need to recalibrate frequently, this according to
the battery manufacturer’s engineers.



It would be nice to offer clients a simple, accurate method of ascertaining
battery charge levels.  SOC is not that method.  I train my clients to
watch voltage levels and to understand these values are elastic.  If you
can see trends in the battery voltage, so much the better. This is why I
like the Outback Optics interface.  This is also why a good AGS system
examines battery voltage over time.



I no longer install Outback FNDC units.  Without them there is no SOC
reading.  I don’t install Sunny Island systems—they are SOC centered and
suffer for it.



William



Miller Solar

17395 Oak Road, Atascadero, CA 93422

805-438-5600

www.millersolar.com

CA Lic. 773985





*From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On
Behalf Of *Jason Szumlanski via RE-wrenches
*Sent:* Sunday, February 4, 2024 7:30 AM
*To:* RE-wrenches
*Cc:* Jason Szumlanski
*Subject:* [RE-wrenches] State of Charge Meter for Sol-Ark



Are there any off the shelf solutions to view battery SOC via a wired meter
mounted remotely on a property? I have a client with a simple voltage based
meter for lead acid batteries that they are accustomed to using as a quick
and approximate gauge of SOC. They want something similar for their new
Sol-Ark with EG4 LL batteries.



They will have smartphone app visibility, but they want something they can
see inside the house without picking up a phone or going out to the
inverter. Ideally the SOC will come from the inverter or the battery
itself, not an external source (to avoid discrepancies).



Jason Szumlanski

Florida Solar Design Group


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Re: [RE-wrenches] State of Charge Meter for Sol-Ark

[Kirk Herander via RE-wrenches]

I have done the cheap tablet route in the same application. Just install a
browser extension to auto refresh the So-ark app screen at an interval of
your choosing. All browsers have add-ons which do it.

On Mon, Feb 5, 2024 at 9:33 AM Jason Szumlanski via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> I don't want to add a device that provides a separate (different) state of
> charge than what is reported by the BMS itself. That is just going to lead
> to confusion and complaints from the homeowner. I was hoping the Sol-Ark
> could feed SOC and voltage information to a simple external display. I'm
> leaning toward the cheap tablet idea, but that isn't ideal because the
> Sol-Ark app doesn't automatically refresh, so it can't be used to display
> the current SOC without physical interaction. I suppose I could use a web
> browser with an auto-refresh feature. But this isn't really what I had in
> mind.
>
> 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 Mon, Feb 5, 2024 at 9:02 AM Chris Schaefer via RE-wrenches <
> re-wrenches@lists.re-wrenches.org> wrote:
>
>> Why not revert to the tried, trued and tested Trimetric 2030 from Bogart
>> engineering? I miss the old 2020 units that we installed on every off grid
>> system back in the day.
>>
>> Christopher
>>
>> On Sun, Feb 4, 2024 at 11:38 AM Glenn Burt via RE-wrenches <
>> re-wrenches@lists.re-wrenches.org> wrote:
>>
>>> Cheap tablet mounted to the wall?
>>>
>>> -Glenn
>>> Sent from my 'smart'phone, so please excuse typos and spelling errors.
>>>
>>> -- Original message--
>>> *From: *Jason Szumlanski via RE-wrenches
>>> *Date: *Sun, Feb 4, 2024 10:30 AM
>>> *To: *RE-wrenches;
>>> *Cc: *Jason Szumlanski;
>>> *Subject:*[RE-wrenches] State of Charge Meter for Sol-Ark
>>>
>>> Are there any off the shelf solutions to view battery SOC via a wired
>>> meter mounted remotely on a property? I have a client with a simple voltage
>>> based meter for lead acid batteries that they are accustomed to using as a
>>> quick and approximate gauge of SOC. They want something similar for their
>>> new Sol-Ark with EG4 LL batteries.
>>>
>>> They will have smartphone app visibility, but they want something they
>>> can see inside the house without picking up a phone or going out to the
>>> inverter. Ideally the SOC will come from the inverter or the battery
>>> itself, not an external source (to avoid discrepancies).
>>>
>>> Jason Szumlanski
>>> Florida Solar Design Group
>>> ___
>>>
>> ___
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-- 

*Kirk Herander / **kirkh@vermont.solar *

*Owner|Principal, VT Solar, LLC*

*Celebrating our 33st Anniversary 1991-2024!!*

dba Vermont Solar Engineering

802.559.1225
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Re: [RE-wrenches] State of Charge Meter for Sol-Ark

[Jason Szumlanski via RE-wrenches]

I don't want to add a device that provides a separate (different) state of
charge than what is reported by the BMS itself. That is just going to lead
to confusion and complaints from the homeowner. I was hoping the Sol-Ark
could feed SOC and voltage information to a simple external display. I'm
leaning toward the cheap tablet idea, but that isn't ideal because the
Sol-Ark app doesn't automatically refresh, so it can't be used to display
the current SOC without physical interaction. I suppose I could use a web
browser with an auto-refresh feature. But this isn't really what I had in
mind.

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 Mon, Feb 5, 2024 at 9:02 AM Chris Schaefer via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> Why not revert to the tried, trued and tested Trimetric 2030 from Bogart
> engineering? I miss the old 2020 units that we installed on every off grid
> system back in the day.
>
> Christopher
>
> On Sun, Feb 4, 2024 at 11:38 AM Glenn Burt via RE-wrenches <
> re-wrenches@lists.re-wrenches.org> wrote:
>
>> Cheap tablet mounted to the wall?
>>
>> -Glenn
>> Sent from my 'smart'phone, so please excuse typos and spelling errors.
>>
>> -- Original message--
>> *From: *Jason Szumlanski via RE-wrenches
>> *Date: *Sun, Feb 4, 2024 10:30 AM
>> *To: *RE-wrenches;
>> *Cc: *Jason Szumlanski;
>> *Subject:*[RE-wrenches] State of Charge Meter for Sol-Ark
>>
>> Are there any off the shelf solutions to view battery SOC via a wired
>> meter mounted remotely on a property? I have a client with a simple voltage
>> based meter for lead acid batteries that they are accustomed to using as a
>> quick and approximate gauge of SOC. They want something similar for their
>> new Sol-Ark with EG4 LL batteries.
>>
>> They will have smartphone app visibility, but they want something they
>> can see inside the house without picking up a phone or going out to the
>> inverter. Ideally the SOC will come from the inverter or the battery
>> itself, not an external source (to avoid discrepancies).
>>
>> Jason Szumlanski
>> Florida Solar Design Group
>> ___
>>
>
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Re: [RE-wrenches] State of Charge Meter for Sol-Ark

[John Blittersdorf via RE-wrenches]

Jason,
  I have found that the TriMetric meter is still somewhat useful and as
with lead acid batteries, still recommend not trusting the SOC.  My
trimetric with no setting changes is
still reading SOC about as unreliable as with lead acid but I use the
voltage readings combined with a printout of a graph of actual voltages
thru the range of full to LBCO
If you don't have data from this customers system, I suspect that a chart
from any similar sized LFP battery would be close enough. I have Fortress
eflex batteries and the Guardian
for remote monitoring of the batteries.  I use it a lot but my wife always
keeps a hawk eye on the Trimetric as we manually start our backup
generator.  The mid range voltages are
plus or minus 20% but at the low end start to change more quickly with
about a 3 hour window to start the generator before LBCO.

John Blittersdorf
offgridvermont.com

On Sun, Feb 4, 2024 at 10:30 AM Jason Szumlanski via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> Are there any off the shelf solutions to view battery SOC via a wired
> meter mounted remotely on a property? I have a client with a simple voltage
> based meter for lead acid batteries that they are accustomed to using as a
> quick and approximate gauge of SOC. They want something similar for their
> new Sol-Ark with EG4 LL batteries.
>
> They will have smartphone app visibility, but they want something they can
> see inside the house without picking up a phone or going out to the
> inverter. Ideally the SOC will come from the inverter or the battery
> itself, not an external source (to avoid discrepancies).
>
> Jason Szumlanski
> Florida Solar Design Group
> ___
> List sponsored by Redwood Alliance
>
> Pay optional member dues here: http://re-wrenches.org
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Re: [RE-wrenches] State of Charge Meter for Sol-Ark

[Chris Schaefer via RE-wrenches]

Why not revert to the tried, trued and tested Trimetric 2030 from Bogart
engineering? I miss the old 2020 units that we installed on every off grid
system back in the day.

Christopher

On Sun, Feb 4, 2024 at 11:38 AM Glenn Burt via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> Cheap tablet mounted to the wall?
>
> -Glenn
> Sent from my 'smart'phone, so please excuse typos and spelling errors.
>
> -- Original message--
> *From: *Jason Szumlanski via RE-wrenches
> *Date: *Sun, Feb 4, 2024 10:30 AM
> *To: *RE-wrenches;
> *Cc: *Jason Szumlanski;
> *Subject:*[RE-wrenches] State of Charge Meter for Sol-Ark
>
> Are there any off the shelf solutions to view battery SOC via a wired
> meter mounted remotely on a property? I have a client with a simple voltage
> based meter for lead acid batteries that they are accustomed to using as a
> quick and approximate gauge of SOC. They want something similar for their
> new Sol-Ark with EG4 LL batteries.
>
> They will have smartphone app visibility, but they want something they can
> see inside the house without picking up a phone or going out to the
> inverter. Ideally the SOC will come from the inverter or the battery
> itself, not an external source (to avoid discrepancies).
>
> Jason Szumlanski
> Florida Solar Design Group
> ___
> List sponsored by Redwood Alliance
>
> Pay optional member dues here: http://re-wrenches.org
>
> List Address: RE-wrenches@lists.re-wrenches.org
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-- 

Chris Schaefer’s


*Tel 585-229-2083 or Cell 585-748-1870 *
*5115 S Hill Road ~ Canandaigua New York 14424**www.solarandwindfx.com
<http://www.solarandwindfx.com> ~ E-mail: ch...@solarandwindfx.com
*


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Re: [RE-wrenches] State of Charge Meter for Sol-Ark

[Glenn Burt via RE-wrenches]

Cheap tablet mounted to the wall?-GlennSent from my 'smart'phone, so please 
excuse typos and spelling errors.-- Original message--From: Jason 
Szumlanski via RE-wrenchesDate: Sun, Feb 4, 2024 10:30 AMTo: RE-wrenches;Cc: 
Jason Szumlanski;Subject:[RE-wrenches] State of Charge Meter for Sol-ArkAre 
there any off the shelf solutions to view battery SOC via a wired meter mounted 
remotely on a property? I have a client with a simple voltage based meter for 
lead acid batteries that they are accustomed to using as a quick and 
approximate gauge of SOC. They want something similar for their new Sol-Ark 
with EG4 LL batteries. They will have smartphone app visibility, but they want 
something they can see inside the house without picking up a phone or going out 
to the inverter. Ideally the SOC will come from the inverter or the battery 
itself, not an external source (to avoid discrepancies).Jason SzumlanskiFlorida 
Solar Design Group 
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[RE-wrenches] State of Charge Meter for Sol-Ark

[Jason Szumlanski via RE-wrenches]

Are there any off the shelf solutions to view battery SOC via a wired meter
mounted remotely on a property? I have a client with a simple voltage based
meter for lead acid batteries that they are accustomed to using as a quick
and approximate gauge of SOC. They want something similar for their new
Sol-Ark with EG4 LL batteries.

They will have smartphone app visibility, but they want something they can
see inside the house without picking up a phone or going out to the
inverter. Ideally the SOC will come from the inverter or the battery
itself, not an external source (to avoid discrepancies).

Jason Szumlanski
Florida Solar Design Group
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