[RE-wrenches] Bootstrapping and AC Coupled Sunny Island

Wed May 8 08:51:20 PDT 2024

William.
We have used FM100's, 80's and 60's to charge numerous brands of lithium
batteries with no troubles.
I don't think you will have any issues in this regard.

Sunny Regards,
Kirpal Khalsa
Oregon LRT#25
Oregon Solarworks LLC
www.oregonsolarworks.com
541-299-0402

On Wed, May 8, 2024 at 8:49 AM jay via RE-wrenches <
re-wrenches at lists.re-wrenches.org> wrote:

> HI William,
>
> Yes the FM-100 has no problem with keeping the volts pretty tight and i’ve
> not heard of any lithium related issues, and someone is bound to chime in
> if there are.
>
> jay
>
>
>
> On May 8, 2024, at 9:39 AM, William Miller <william at millersolar.com>
> wrote:
>
> Jay:
>
> I am considering ditching the Sunny Boys and installing 2 Outback FM100s.
> It seems to me this might solve a few problems:
>
> 1. The cc should voltage clamp and prevent over voltage when the batteries
> go higher Z.
> 2. The CCs should start up at lower voltages as soon as the sun comes
> out.
> 3. One of the FM 100s could be configured to drive an AGS relay.
> 4. The operation would be voltage dependent, not SOC dependent.
>
> My concern is the shallow voltage/charge curve. Can I set this system fine
> enough to work reliably?
>
> Has anyone used Outback charge controllers with lithium batteries?  Any
> advice?
>
>
> William Miller
> Miller Solar.com
> 805-438-5600
> www.millersolar.com
>
>
> On Wed, May 8, 2024 at 8:30 AM jay <jay.peltz at gmail.com> wrote:
>
>> Hi William,
>>
>> Since the SOC isn’t being reliable maybe due to not charging correctly?
>>
>> I would recommend going to volts for the relay driver.  Thats why I
>> suggested the tristar with RD-1.
>> Because really volts at full is the most accurate.
>> Not knowing how many PV inputs you could do a cascade.
>>
>>
>> jay
>>
>> On May 8, 2024, at 9:00 AM, William Miller <william at millersolar.com>
>> wrote:
>>
>> Jay:
>>
>> Thank you for taking the time.
>>
>> We are doing just what you suggest as an interim solution.
>>
>> The shortcoming of this work-around is that the highest setting for this
>> relay function is 90% SOC. This may not be high enough to recalibrate the
>> BMS units. And again, relying on SOC to drive operational decisions becomes
>> problematic when one can’t rely on the accuracy of the SOC value.
>>
>>
>> William Miller
>> Miller Solar.com <http://solar.com/>
>> 805-438-5600
>> www.millersolar.com
>>
>>
>> On Wed, May 8, 2024 at 7:16 AM jay <jay.peltz at gmail.com> wrote:
>>
>>> A possible fix.
>>>
>>> You could run a DC relay on the SB PV input that would be voltage
>>> triggered to prevent the battery volts from getting higher than you want.
>>>
>>> The SI has 2 aux relays I think?  Or could do a tristar with RD-1 relay
>>> that has 4 channels.
>>>
>>> Just a thought
>>>
>>> jay
>>>
>>> On May 7, 2024, at 11:11 PM, William Miller via RE-wrenches <
>>> re-wrenches at lists.re-wrenches.org> wrote:
>>>
>>> Friends:
>>>
>>>
>>> I am still wrestling with problems integrating a Sunny Island / Sunny
>>> Boy AC coupled system to a set of 5 E-vault Max battery cabinets.
>>>
>>>
>>> As a refresher, with closed loop comms, the Frequency Shift Power
>>> Control system is not working, or not working quickly enough, and when
>>> nearing full charge, the voltage can spike up to 66 volts and the SI system
>>> shuts down.  Fortress has told me in a roundabout way that they agree this
>>> is a real problem and they are working on a solution.
>>>
>>>
>>> Another problem has reared its head:  If the E-Vaults do not get charged
>>> fully every 5 to 7 days, the BMS units SOC value becomes radically out of
>>> calibration.  The E-vault will report a higher SOC than is realistic.  The
>>> SI system starts the generator based on SOC and if the SOC is reported as
>>> high the generator don’t start.  Sooner rather than later the battery
>>> voltage gets too low and the system shuts down.
>>>
>>>
>>> I have been tweaking on the settings like days-since-full-charge to
>>> attempt to get this cycle to stop.  No definitive answer yet.
>>>
>>>
>>> Here is the reason I am writing:  Yesterday I could not get the Sunny
>>> Islands to start.  The battery voltage was 46 which should have been enough
>>> but for some reason they just would not start.  Because of this I could not
>>> charge the batteries from generator or from AC coupled solar.  I called SMA
>>> but they told me they could not advise because of the non-compatible
>>> batteries.  I asked about the emergency charging procedure in the manual
>>> but I was told this does not work with lithium batteries.  The process is
>>> pretty scary anyway so I was not inclined to try.
>>>
>>>
>>> SMA told me I may need an external 48 volt charging system.  I have
>>> heard of this being required in certain scenarios by wrenches.  This would
>>> be a huge pain in the ass: ordering one, waiting for it, hooking it up, etc.
>>>
>>>
>>> Here is what I did:  I initiated the Quick Start Configuration mode and
>>> told the SI system there was a new battery bank.  I told it the bank was a
>>> very small VRLA battery.   The SI system accepted the 46 volts, started up
>>> and allowed a generator charge.  After an hour or so we reprogrammed the
>>> system for lithium and problem resolved, at least for now.
>>>
>>>
>>> Hopefully this trick may help one of you some day.  If it does, it was
>>> worth my time typing it out.
>>>
>>>
>>> William
>>>
>>>
>>> Miller Solar
>>> 17395 Oak Road, Atascadero, CA 93422
>>> 805-438-5600
>>> www.millersolar.com
>>> CA Lic. 773985
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> 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/20240508/51937055/attachment-0001.htm>