AIO Solar Controller(s) VS Stand-Alone SCC's ! ? Penny Wise & Dollar Foolish or NOT ??

[Steve_S]

I have been here a while and watching everyone running towards AIO's and for many good reasons BUT not seeing (looking) at the other side of this.

Every AIO has Solar Controllers - anywhere from 1 to 4 SCC's built-in (on average), sometimes more depending on model & sizing.
Each SCC is capable of outputting XX Amps for charging. Depends on how many Volts/Watts/Amps each can handle.

I looked through EG4 & Other spec sheets looking for how many AMPS of Charge is provided, be it collectively or individually. No Info Available !!!
Some do however state a max amperage incoming like 35A, 25A & 15A (in units with 3 SCCs for example.)
Now we have people installing 10,000W or more solar arrays to feed their AIO SCC's.
So Far So Good

I have Standalone SCC's.
#1 has 2080W (4s2p) provides 200V and gives 79A Charge. #2 has 2370W (2s3p) and provides 94A Charge,
4,450W providing 173A Charging
Edit: Thanks to 420OhmsPA: Clarifying, this is based on 24V System info but still.
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NOTICE SOMETHING ????
Are AIO's Penny Wise & Dollar Foolish ?
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To Vendors / Suppliers & Manufacturers even.
Clearly STATE the Amperage that EACH Internal SCC can provide with it's Maximum Solar Input Capacity.

QUESTIONS for @Will Prowse
Would it be possible for you to look at the assorted AIO's and provide such info or your observations with them in this regard.
Maybe have some of your friends from Signature, high-tech lab etc chime in as well...
(real, verifiable, credible & observable & reproduceable info only OK... no marketing shlock.)

*NB: When discussing StandAlone SCC's, I am referring to Midnite/Victron and similar, not bargain basement discount value gear.

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The general question tossed into the pond.
I am frugal and squeeze the value out of the gear. Why would I spend on 10kw of panels when I can do better with 1/2 that (for charging) ?
Some may not care, others would who are on a tight budget and managing their cash.
What's your take ?

 

[42OhmsPA]

You should clarify you're talking about a 24V bank in your calculations, took me a second because my mind has been stuck on 48V since I upgraded from a 24V modular system to a 48V 10KW AIO.

I thought the specs in mine were laid out clear and easy to understand.

I'm feeding MPPT 1 5180W but I'm slightly over max input current, MPPT2 is 5670W but arrays are different orientations.
I've seen 180+ amps going into my bank, ~0.25C, when my AC loads are low.

 

[Steve_S]

You should clarify you're talking about a 24V bank in your calculations, took me a second because my mind has been stuck on 48V since I upgraded from a 24V modular system to a 48V 10KW AIO.

I thought the specs in mine were laid out clear and easy to understand.

I'm feeding MPPT 1 5180W but I'm slightly over max input current, MPPT2 is 5670W but arrays are different orientations.
I've seen 180+ amps going into my bank, ~0.25C, when my AC loads are low.

SNRE does have those specs, KUDO's to them ! look at EG4, Growatt, MPP and others, some have that info and many don't.

 

[SparkyJJO]

Well they list the total MPPT wattage, right?
And you know your battery voltage.
From there it is easy to calculate the max charging amperage. I = P/V

Sure it might be nice if it is listed but doesn't really matter all that much, IMO. How close you get to the max will be partly determined by the panels you choose to go with, and what config you use.

 

[Mattb4]

I fail to follow your logic. Whether component or built together the specifications for what they can do is not hard to lookup. There are use cases for either setups. I do note you wish to compare high quality single components to some basic quality AIO's.

 

[MrSparkle]

From there it is easy to calculate the max charging amperage. I = P/V

I do also find it strange if a manufacturer does not list all vital info about the product. One should not have to calculate I from P/V. Also, since we live in a world where insurance states total obedience of specifications to be valid, it is fundamental flaw to have to "guess" (calculate) PROBABLE max I.

 

[marionw]

Look at in in watts/power. As @42OhmsPA posted in #2 for his inverter for an MPPT (I believe his inverter has two); max 22 amps x 500 vdc = 11,000 watts (although the input max voltage really is 425 vdc). 11,000 watts / 56 vdc charging volts = 196.42 amps (there will be conversion losses)

Total battery charging current is limited by the "Max PV Charging Current" which is an inverter setting you can program and in #2 is limited to 200 amps.

I always recommend downloading and reading the spec sheet and user manual before purchase. I also recommend that the inverter (or batteries) manufacturer/distributor also provide software that allows you to monitor the device as well if necessary, to upload new firmware.

 

[Partimewages]

I like having max wattage of each input and then max overall wattage for the total of all inputs. Then max voltage for each.

 

[Steve_S]

Having dealt with various SCC's and most anyone who has (vendors/users) know that NOT All MPPT Controller are the same or equivalent. How the MPPT is coded & implemented can make a huge difference... ie compare a cheapo "value Grade" MPPT & a Top Tier like Outback/Victron/Midnite and Holy Macaroni what a difference.

Honestly, does anyone think that a $1200 AIO with 2 SCC's will have SCC's that are anywhere near as capable/functional or efficient like a Victron or other ?

I would like to see @Will Prowse take on this and maybe some proper feedback from Primary AIO Vendors like Sig Solar etc... who also carry non AIO Quality Goodies.

Often Times when something looks like a really good deal (tipping too good to be true) is often not what is "expected". The trade-offs get ya in the end regardless.

 

[Brucey]

Having dealt with various SCC's and most anyone who has (vendors/users) know that NOT All MPPT Controller are the same or equivalent. How the MPPT is coded & implemented can make a huge difference... ie compare a cheapo "value Grade" MPPT & a Top Tier like Outback/Victron/Midnite and Holy Macaroni what a difference.

Honestly, does anyone think that a $1200 AIO with 2 SCC's will have SCC's that are anywhere near as capable/functional or efficient like a Victron or other ?

I would like to see @Will Prowse take on this and maybe some proper feedback from Primary AIO Vendors like Sig Solar etc... who also carry non AIO Quality Goodies.

Often Times when something looks like a really good deal (tipping too good to be true) is often not what is "expected". The trade-offs get ya in the end regardless.

The sad fact is that my ~$1100 Victron 450/100 can be outproduced by a $1200 AIO. Because the user can just throw a bunch of panels at the optimization problem. The vast majority of users may not be interested in ultimate efficiency/max harvest per array in partial shade, zero risk of failure mode where PV voltage can reach the batteries, quiet operation etc. They see the big wattage numbers and shiny brochures and internet ads and hit the buy button. Just slap a bunch of super cheap panels on each tracker. Later after installing they realize the aio is insanely loud from cooling fan noise once inverting or charging to any significant degree. and they need a chargeverter because stray pv voltages can float around the battery bus or wierd stuff like that.

That said it's always been clear to me what the eg4 solar capabilities are, it's on their spec sheets:

 

[Will Prowse]

I absolutely love my Victron MPPT, especially the isolated input. But for the price, it really does not make sense.

For my videos, having data logging with multiple trackers makes it extremely easy to compare performance of panels. And low required string voltage to charge 48V batteries....

But the price is just silly. I really wish they could sell these victron MPPT for cheaper. Most people would not spend the money to get these.

 

[rhino]

Overriding factor for many will be simplification as well. It's a lot easier for somebody who isn't familiar with your system to understand it, fix it, etc. if it is an AIO where they are only having to deal with one single device with very few wires.

 

[Will Prowse]

Overriding factor for many will be simplification as well. It's a lot easier for somebody who isn't familiar with your system to understand it, fix it, etc. if it is an AIO where they are only having to deal with one single device with very few wires.

And these days, how often do people burn out a MPPT? Pretty rare. Imagine having a modular computer. Not putting the CPU GPU Ram into one box. Imagine saying that you need to have separate boxes so you can work on individual components. I just think everything will gravitate toward AIO design over time. Especially with how reliable these devices are now becoming.

 

[Steve_S]

I bought Midnites (Victron was not available back then in Canada) and they are really super but at a Grand Ea "ouch".
Victron has been dropping their prices and SHNOOTZ not bad !
I'd switch BUT I'm eyeball deep into Midnite (E-panels etc too) and there is no point for me to do so anymore.

Will I remember when I first pointed you at Growatt AIO's "way back in the day" and you weren't pleased with the notion of AIO's at that point... Yeah a while back to be sure. Psst back when we were still playing with those Chargery BMS (way back)...

Being Remote, Rural and offgrid I always put 1 thing above all else, Fault Tolerance / Fall Back in case something goes awry ! May not be able to go 250km to get a "part" if something fails quickly to replace part X. I have to beat stuff (thrash test) things to make sure it does what's its supposed in the extreme ends of situations so I know I will be fine with the gear I have chosen. I've shared some of that but most didn;t give a flying flip.

At least I know if one SCC stops the other will continue along happily and I stay up and have time to replace if needed.

 

[Mattb4]

...e.

Honestly, does anyone think that a $1200 AIO with 2 SCC's will have SCC's that are anywhere near as capable/functional or efficient like a Victron or other ?

...

I do not think the Victron SCC is all that capable. It lacks any display. It has wire terminals that some folks have problems with and I do not have any data that suggests that it produces more watts per day in enough of a difference to the SCC's in AIO's .

I would certainly hope a product that cost an arm and leg more than another product was truly superior. Test results would be of interest.

 

[Brucey]

I do not think the Victron SCC is all that capable. It lacks any display. It has wire terminals that some folks have problems withand i do not have any data that suggests that it produces more watts per day in enough of a difference to the SCC's in AIO's .

I would certainly hope a product that cost an arm and leg more than another product was truly superior. Test results would be of interest.

We are talking about the rs450/100 and 200 models which allow for lugs, has a display, bunch of other assorted features. Below is my 100. The 200 has dual terminals and four trackers. It is very useful to compare different arrays of panels.

 

[Brucey]

I bought Midnites (Victron was not available back then in Canada) and they are really super but at a Grand Ea "ouch".
Victron has been dropping their prices and SHNOOTZ not bad !
I'd switch BUT I'm eyeball deep into Midnite (E-panels etc too) and there is no point for me to do so anymore.

Will I remember when I first pointed you at Growatt AIO's "way back in the day" and you weren't pleased with the notion of AIO's at that point... Yeah a while back to be sure. Psst back when we were still playing with those Chargery BMS (way back)...

Being Remote, Rural and offgrid I always put 1 thing above all else, Fault Tolerance / Fall Back in case something goes awry ! May not be able to go 250km to get a "part" if something fails quickly to replace part X. I have to beat stuff (thrash test) things to make sure it does what's its supposed in the extreme ends of situations so I know I will be fine with the gear I have chosen. I've shared some of that but most didn;t give a flying flip.

At least I know if one SCC stops the other will continue along happily and I stay up and have time to replace if needed.

Sounds like you are all set with the Classics, for more recent prospects the 90 and 120A hawkes bay single tracker and 200A dual tracker Barcelona are pretty similar to Victron 450/100-/200 pricing, for the newer midnite canbus ecosystem along with Rosie.

 

[Mattb4]

We are talking about the rs450/100 and 200 models which allow for lugs, has a display, bunch of other assorted features. Below is my 100. The 200 has dual terminals and four trackers. It is very useful to compare different arrays of panels.

Sounds expensive and a competitor of the Midnite Solar SCC. Does it really produce more than a SCC incorporated into an AIO?

 

[Brucey]

Sounds expensive and a competitor of the Midnite Solar SCC. Does it really produce more than a SCC incorporated into an AIO?

Yes I believe it does, but nowhere near a 50% increase as Steve had aluded to earlier. If you have an AIO, just add an additional panel or two and you'll prob be out producing a higher end controller.

 

[Steve_S]

Aluded to ? Not Quite.
As a couple showed, SOME AIO specs sheets do show what each SCC is capable of while others do not.
MPPT Code also is different between companies, some are really really good while others are not. (no I am not talking the "brand" MPPT that circulated a while back. (talk about scamming folks eh)

Honestly a Good High Quality MPPT Controller also comes with high quality components *chips etc" and excellent code which all comes at a cost. Can someone match & do the same with stuff that costs 75% less and using common open source MPPT code ? Doesn;t seem likely to me but what do I know.

AIO's do have several advantages as it has been pointed out and yeah, it's pretty obvious on many points. No argument there at all. They are also "Fixed Voltage" as in 24V/48V etc so their SCC's don't need to support multi-voltage battery packs, just the one, so that saves on bits & pieces too but how much really.

Would be nice to see Real Tests & Comparisons that evaluate SCC's in their various forms. Even better would be to see comparisons between MPPT Efficiencies & perfrnce. Not Likely such will occur.

 

[Crowz]

One thing to keep in mind when it comes to all in ones they have an advantage in a hybrid setup since it can run without any batteries at all and all of the power goes to shaving off grid usage vs charging the battery. An external mppt can only charge the battery. An aio in hybrid mode does not use the battery at all so the built in mppt is the only source of pv power in that setup.

Using hybrid setups has made me have to calculate what to invest in different areas equipment wise to ensure as little grid usage as possible.

 

[Brucey]

Aluded to ? Not Quite.
As a couple showed, SOME AIO specs sheets do show what each SCC is capable of while others do not.
MPPT Code also is different between companies, some are really really good while others are not. (no I am not talking the "brand" MPPT that circulated a while back. (talk about scamming folks eh)

Honestly a Good High Quality MPPT Controller also comes with high quality components *chips etc" and excellent code which all comes at a cost. Can someone match & do the same with stuff that costs 75% less and using common open source MPPT code ? Doesn;t seem likely to me but what do I know.

AIO's do have several advantages as it has been pointed out and yeah, it's pretty obvious on many points. No argument there at all. They are also "Fixed Voltage" as in 24V/48V etc so their SCC's don't need to support multi-voltage battery packs, just the one, so that saves on bits & pieces too but how much really.

Would be nice to see Real Tests & Comparisons that evaluate SCC's in their various forms. Even better would be to see comparisons between MPPT Efficiencies & perfrnce. Not Likely such will occur.

You proposed a theory:

"The general question tossed into the pond.
I am frugal and squeeze the value out of the gear. Why would I spend on 10kw of panels when I can do better with 1/2 that (for charging) ?
Some may not care, others would who are on a tight budget and managing their cash.
What's your take ?"

Have I misinterpreted your question? You seem to be saying it's possible to harvest twice as much from a tier 1 mppt versus an AIO given the same panels?

 

[42OhmsPA]

Honestly, does anyone think that a $1200 AIO with 2 SCC's will have SCC's that are anywhere near as capable/functional or efficient like a Victron or other ?

Based on my experience the difference is negligible. I know it's not apples to apples because I only have a Victron 100/20. The main thing I noticed is the Victron makes power longer, meaning starts up earlier and stops later; however the power it's making is miniscule but every watt counts.
I've seen both produce what the panels are rated for enough times to stop paying attention and know they will just work.

It was nice having the separate MPPT when building my 4th pack, I simply removed it from my main bus and used it to charge the pack.
I'm not for or against modular systems, as long as something works and is reliable I don't care if it's 1 box or 5 boxes. Now if I were completely off the grid in the middle of bumblefeck modularity could be nicer if something failed and needed replaced but the price of these "budget" AIOs makes it easy enough to keep a spare and swap the entire box out in 30 minutes.

Anyway I'm starting to ramble and lunch is almost ready.

 

[DIYrich]

There is Panel -> Battery voltage efficiency of the MPPT and AIO, and Panel -> AC efficiency of the AIO.

With Panel -> Battery Voltage -> AC (assuming immediate consumption or export), that is naturally less efficient that Panel -> AC Efficiency.

With Panel -> AC, the AIO MPPT is converting string voltage to AC Inversion voltage (300-400v) so the Inverter can make 120/240v Split Phase AC (or 230v for europe). With a separate MPPT, the MPPT converts to 48v, and then another circuit has to boost it to 300-400v for the AC inversion.

Also, the "best" MPPT is install dependent. I have 3 roofs, each with 14 panels. Because of Voc, it has to be

 

[Hedges]

Well they list the total MPPT wattage, right?
And you know your battery voltage.
From there it is easy to calculate the max charging amperage. I = P/V

Not quite. There are 3 blocks of conversion hardware.

MPPT, PV --> HV DC rail
Inverter, HV DC rail <--> AC
DC/DC bidirectional charger, HV DC rail <--> battery

For the case of HV DC rail, typical for most HF AIO.

I looked through EG4 & Other spec sheets looking for how many AMPS of Charge is provided, be it collectively or individually. No Info Available !!!

Here's one, SMA SBSE 7.7

15kW PV processed,
10kW battery charging (8kW discharging)
7680VA AC output (240V)

https://files.sma.de/downloads/SBSE-US-DS-en-24.pdf

They note in particular that it supports PV wattage 2x inverter wattage, with the excess going to battery. Limited to 10kW, the spec sheet indicates, applicable if inverter is curtailed either due to grid operator controlling it or less load when running offgrid.