This is my schematic. Is it correct?

MikeMynis said:

(8 batteries) is not 'too much' for the Growatt.

Click to expand...

Not sure what secret batteries you have but you need to see what their max charging rate is, as recommended by maker. That will determine what your 100A (max) charge rate should be limited to. That's a lot of battery but you should figure out how much they can safely accept before throwing 100A at them.

Sorry for confusing you.

It is still 1 array of 8 panels in series.

And I had 2 battery arrays. Let's call them battery banks, to prevent confusion.

So there are 2 battery banks. Each bank has 4 x 12V batteries, making 48 V, 260Ah.
Both banks are parallel connected to double the capacity to 520Ah.

So I was referring to probably adding a 3rd battery bank, in parallel, making 48V, 780Ah.


I'll see if I can get some more detailed info about the max. charge current for these batteries.

MikeMynis said:

So I was referring to probably adding a 3rd battery bank, in parallel, making 48V, 780Ah.

Click to expand...

51.2V x 780Ah = 39,936Wh (19968Wh usable)

19,936Wh / 3600W solar = 5.54h to completely recharge with everything operating at 100% efficiency

That's still with the array providing 64% of what your Growatt can use.

Okay, got it. I was confused too. So I have room to extend the SOLAR array.

Now it's 8 panels in series.

I could make it 12 solar panels divided into 2 arrays.
Each solar array has 6 panels in series.
Each panel still has a Vmp of 41.50 V.
6 x 41.5 = 249 V per solar array.
The solar voltage falls still within the range for the Growatt (120VDC-430VDC).

Then connect these 2 solar arrays in parallel.

2 solar arrays of 6 panels = 12 panels in total.
12 x 450W = 5400 Watt.

100A charging at 56V = 5600W
The 12 solar panels together can then provide 5400/5600= 96% of what the Growatt is rated for.
I think this is a better match.

So far correct?

MikeMynis said:

So far correct?

Click to expand...

Exactly.

You can always throttle the SCC back to whatever your batteries can handle.

What are you mounting your panels on? If you are making a ground mount, you can angle one 6S array east-ish to start charging earlier and point other other 6S array west-ish to charge later. This spreads out the charging over a longer period at lower amps. This is gentler on the equipment.

I wish I had the space to make a ground mount. But I don't have that.

So it's gonna be roof mounted. It's angled around 15° and facing south. Enough room for mounting 12 panels (even 24 if I wish to do so in a later stadium).

And it's in the southern part of Spain. So pretty much sun here, averaging 320 days of sunshine each year.