[RE-wrenches] Need a hand with Sunny Island/Sunny boy AC couple

Sun Oct 22 05:13:35 PDT 2023

Hi William,

I think you will find that the state of charge discrepancy will be a
continual problem to contend with in voltage mode.  The state of charge
algorithm that the SI uses (and bases all decisions) is complex and not
very Lithium compatible when at the ends of the state of charge spectrum
(full, empty).  The Sunny Island will continually interpret the SOC much
too high when the eVaults are low because there isn't much voltage drop
across most of the battery capacity.

Do you have RS485 communication going to the Sunnyboys?  You will also need
to set your Sunnyboys off-grid.

I would probably try to get a battery voltage based relay installed that
opens the AC connection to the sunnyboys at 56V or so.

I would also call Fortress to see how well the SunnyIsland to BMS
communications works.  Even if SMA won't support it, Fortress may have some
honest field experience by now and be able to advise.  If the communication
stops flowing, the SunnyIsland will register an external BMS fault and shut
off which seems lower risk than having the bus voltage spike to 69V

Let us know what you learn on this one.

On Sun, Oct 22, 2023 at 5:30 AM Chris Sparadeo via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> Hi William,
>
> You will want to make sure that the eVaults are all running that same
> firmware and that terminator switches and battery ID #s are set correctly.
> High SOC and large incoming current could definitely be the reason why
> voltage skyrocketed up.
>
> Best,
>
> Chris
>
> On Sat, Oct 21, 2023 at 9:39 PM William Miller via RE-wrenches <
> re-wrenches at lists.re-wrenches.org> wrote:
>
>> 12 kw PV nominal. Low tilt angle and old panels so reality is far less.
>> 5 e-vault 18.5 kWh batteries
>> 4 SI 6048
>> 2 SB 6000 US
>>
>> System operational for some years with flooded batteries. Just installed
>> the e-vaults. I reset the system to factory defaults. I am not sure how to
>> verify the system will properly offset frequency if batteries are full.
>>
>> Having just written this I realize there is a discrepancy between the SOC
>> the SIs report (46%) and the SOC the e-vaults report (98%). It could be the
>> SIs want to push a lot of charge to the e-vaults but they won’t accept the
>> charge because they are charged.
>>
>> I installed 3 of the vaults temporarily a week ago. At first there was a
>> large discrepancy between SOC from batteries to SIs. Eventually that delta
>> reduced to 4%. Maybe this problem will resolve itself?
>>
>> What settings on the SI are necessary to enable frequency shifting?
>>
>> Thanks everyone for the response. There is nothing worse than being
>> on-site and not knowing how to get a system to operate. I shut off the PV
>> and will let the generator fill in the deficit until Monday.
>>
>> William Miller
>> Miller Solar.com
>> 805-438-5600
>> www.millersolar.com
>>
>>
>> On Sat, Oct 21, 2023 at 4:57 PM Ray Walters via RE-wrenches <
>> re-wrenches at lists.re-wrenches.org> wrote:
>>
>>> What is the array size vs the battery size?  Sounds like a big array on
>>> a small battery for the voltage to go that high that fast.
>>>
>>> Ray
>>> Remote Solar
>>> On 10/21/2023 5:46 PM, William Miller via RE-wrenches wrote:
>>>
>>> Friends:
>>>
>>> I’m kinda stuck on a project setting up a SI/SB AC coupled system off
>>> grid. When the SB inverters ramp up the battery voltage jumps to 69 pretty
>>> quickly and the system shuts off.
>>>
>>> I checked the mini-grid frequency and it does ramp up to about 62+ but
>>> apparently not soon enough to curtail charging. I shut off the SBs for now
>>> and we can rely on generator.
>>>
>>> Any advice via email or a phone call would be appreciated.  SMA can be
>>> less than helpful, especially for systems with lithium batteries.
>>>
>>> Thanks in advance.
>>>
>>> William Miller
>>> Miller Solar.com
>>> 805-438-5600
>>> www.millersolar.com
>>>
>>> _______________________________________________
>>> 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
>
>

-- 

Mac Lewis

*"Yo solo sé que no sé nada." -Sócrates*
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20231022/afd0b1cd/attachment.htm>