SMA Sunny Island 5048

palausystem · December 2012

I've generally had good help from SMA tech support but lately I seem to be asking questions that they can't easily answer, and the SMA forum looks like it's dead or dying. I'm hoping this thread can be a place for SI owners to share their frustrations and successes.

At the very least, I'm looking for feedback on my current situation:
The automatic "Full" charges aren't happening. I've referred to the manual more times than I can count and don't find an answer there. It seems that the Boost charges are being added up in such a way that the SI decides the Full charge is not necessary. I can see this by looking at the logs via the Webbox - the days-remaining-till-Full counter resets itself at some point during the Boost charge. Last year, when I discovered this was happening, I checked the installer's settings and found that Boost absorb duration was set at 2hrs, and the Full was set at a measly 2.5hrs. The Boost voltage was also set higher than Full. I got an answer back from SMA explaining that in our situation the Boost on its own was fulfilling the Full, and that the SI was trying not overcharge the battery, and so would reset the counter. This made some sense given the settings, but then I set the Full duration to 5hrs, and set the voltage the same as Boost. No difference.

Because I now do manual Full charges, the automatic aspect isn't as important as it was when I expected the SI to take care of my batteries on its own. But there must be something wrong with the SI....anyone else run into this kind of thing...or want to share their experience with the SI?

-John

stephendv · December 2012

Re: SMA Sunny Island 5048

Hi John,

I charge my batteries with a Midnite Classic controller, so only use the SI 5048 for the very occasional generator charge. Nevertheless, the SI still changes its charge type and the days to full based on the battery state, so I can see how it would want to charge if I were charging through it.
Midnite is set to absorb at 2.4V and use end amps to stop absorb, which usually means an absorb of under 2 hours in this sunny weather.
Midnite is set to "EQ" at 2.5V for 4 hours every 7 days. I'm experimenting with this as a half-way point between a full EQ and a long absorb, equivalent to the SI's full charge.

The SI's boost is configured to absorb at 2.39V for 2 hours.
SI's Full is configured to absorb at 2.39 for 3.5 hours.

Since the SI's settings are shorter and lower than the midnite, so far it has reset the days to full as expected.

What are your settings for boost, full and EQ ?

palausystem · December 2012

Re: SMA Sunny Island 5048

Stephen,

float 2.2v
boost 2.5 3hrs
full 2.5 6hrs
Rolls allows 2.4 - 2.5v ( tech support)

I may have been hasty in my judgement - I checked the logs again and it seems that when the SOC reaches 95% the Full will reset. So, if once a week I reach 95%, and twice a week it boosts to the high 80's SOC, then I will have spent 9 hrs absorbing, and the Full will have been achieved. But that is over the course of a week, and I thought what you want is for those hours to be consecutive.

Why do you use the Classic and not the SI for charging?
And the EQ you do, is that to "de-stratify" the electrolyte?

Thanks,
John

stephendv · December 2012

Re: SMA Sunny Island 5048

palausystem wrote: »

I may have been hasty in my judgement - I checked the logs again and it seems that when the SOC reaches 95% the Full will reset. So, if once a week I reach 95%, and twice a week it boosts to the high 80's SOC, then I will have spent 9 hrs absorbing, and the Full will have been achieved. But that is over the course of a week, and I thought what you want is for those hours to be consecutive.

My understanding was that they're meant to be consecutive hours. I also understood the full charge to be compulsory and not something that could be skipped because SoC reached 95%, in fact as I understood it, the SoC measurement itself is meant to reset based on whether the full charge was reached or not:
When the full charge states are reached, the battery state of charge is reset to values of 90 %, 95 % or 100 %, depending on how full battery was actually charged. If default settings are not changed, a state of charge of 80 % after boost charge, 95 % after full charge and 100 % after equalization charge is reached.

palausystem wrote: »

Why do you use the Classic and not the SI for charging?

It's more efficient charging in winter than a Sunny Boy + SI and it's half the price of a 3kW Sunny Boy

palausystem wrote: »

And the EQ you do, is that to "de-stratify" the electrolyte?

Yep. The disadvantage of the classic is that it doesn't have a Full and EQ charge, just an EQ. So I'm using the EQ setting to do what is effectively a high voltage full charge. I want to be sure the batt reaches 100% and I want to mix the electrolyte up. Have just starting doing this, so don't know whether it works yet.

palausystem · December 2012

Re: SMA Sunny Island 5048

... in fact as I understood it, the SoC measurement itself is meant to reset based on whether the full charge was reached or not:

Yes, that makes sense...

"When the full charge states are reached, the battery state of charge is reset to values of 90 %, 95 % or 100 %, depending on how full battery was actually charged. If default settings are not changed, a state of charge of 80 % after boost charge, 95 % after full charge and 100 % after equalization charge is reached."

Wording like that in the manual is part of the problem: "...the full charge states..." I thought there was only one full charge state...? But wait, OK, they mean each time "Full" is reached, so they make it plural. So, when full charge state is reached, the SOC value is reset to one of 3 numbers: 90, 95, or 100. Fair enough. Then, "If default settings are not changed..." would anyone not change the defaults (except for maybe my installer)? That is, the defaults will all change depending on the total system. From elsewhere in the manual: "The boost charge process can charge the battery up to approx. 85 % to 90 %." Wait, that number is supposed to be more like 80%...? But they used the word can, so I need to take that into consideration. Oh well. It's almost as if they don't want to get too technical.

The disadvantage of the classic is that it doesn't have a Full and EQ charge, just an EQ

The SI will allow you to manual EQ, but not manual Full. Go figure. You can program in a Full, but that is only automatic, and as we've seen, only happens under very particular circumstances. So I end up like you, using the manual EQ to do a full charge.

stephendv · December 2012

Re: SMA Sunny Island 5048

I see what you mean.

To be sure that boost isn't being counted as being part of full you could try setting the voltages slightly differently. E.g. boost at 2.49V and full at 2.5V. This should mean that it never counts boost as contributing towards full.

palausystem · December 2012

Re: SMA Sunny Island 5048

Yes,
good idea,
I thought of that work-around. I need the generator in winter to help out with the full-charge and we like to choose the hours it runs. But in Summer, I will do that voltage trick and I bet it will work fine.

I'm wondering if you've ever noticed on yours - the SOC can be 98% and the error factor can be 7%. Since the SOC can jump up or down when the error goes down, this is a little odd.

Also, our battery State of Health number is at 120%... That should never happen...

stephendv · December 2012

Re: SMA Sunny Island 5048

palausystem wrote: »

I'm wondering if you've ever noticed on yours - the SOC can be 98% and the error factor can be 7%. Since the SOC can jump up or down when the error goes down, this is a little odd.

Yeah I've seen that before, but it doesn't bother me much- any battery monitor is going to have a margin of error, they just don't show you what it is

palausystem wrote: »

Also, our battery State of Health number is at 120%... That should never happen...

Haven't you been disconnecting the batteries and using just one string at a time? If so, you've halved the battery capacity which is going to screw with the SoC and SoH values.

palausystem · December 2012

Re: SMA Sunny Island 5048

As far as the SOH goes, yes...I think you may be right about switching to a single string to EQ it and thus resetting the battery to New Battery to enter the single string parameters (and then back again)
This same thing did however happen last year, a big jump in SOH to over 100%, and that was apparently cured with a firmware update.
But since I will be doing the single-string EQ's again I won't stress about it as the SOH will have to reset again anyway.

It looks like not a lot of folks use the Sunny Island in the off-grid world, judging by the amount of interest this posting has generated. What appealed to you about using this machine over others?

stephendv · December 2012

Re: SMA Sunny Island 5048

palausystem wrote: »

It looks like not a lot of folks use the Sunny Island in the off-grid world, judging by the amount of interest this posting has generated. What appealed to you about using this machine over others?

It doesn't seem to be very popular in the Americas as an off-grid solution because it's 110V only and is more expensive compared to other systems that offer 220/110V split phase. In 230V land it's more popular in pure off-grid circles. Seems that in the US it's sold as a backup system in cases where people already have a grid connected solar array. In Europe it's illegal to use it as a backup system in some countries- for that there's the "Sunny Backup" product (yes there's a "sunny X" for everything). So it was designed to be a 100% off-grid inverter right from the start, and this is reflected in its programming too (in the EU version at least).

There's a dedicated section to Sunny Island's on this german forum: http://www.photovoltaikforum.com/sma-insel-wechselrichter-off-grid--f46/ (Google translate sort of works)
And this Spanish forum: http://www.solarweb.net/forosolar/soporte-tecnico-sma/
The newly launched SMA Aus and the old SMA US forums seem to be semi-dead with infrequent answers from tech support. If you're really struggling, try SMA Germany, they all speak English.

Personally I chose it because:
- Competitors were only slightly cheaper and offered fewer features (e.g. no built in SoC, no AC coupling option, no programming console built in)
- 5 year warranty extendible to 25 years
- Great support from SMA Germany
- Option to AC couple in the future
- SMA is leading inverter manufacturer worldwide, so I can count on them being around for a while

SMA Sunny Island 5048

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