Beginner looking for advice on set-up

[Rednecktek]

I got my Growatt 3Kw from Watts247 many years ago and even though I just recently got it installed it worked great (while I had sun for that one day) and fired up both my little 10gal air compressor and the miter saw without throwing a fit. Only downside to it was that I had to open it up and take out a few screws to prevent it from doing the N-G bond that would fight with the rest of the wiring and the 60w of standby power draw. Still, for the few options that are available in 24v I figured the extra few hundred watts for the same money (actually cheaper at that time) was totally worth it.

Since you're making a standalone system, you don't have to worry about the N-G bonding screw stuff.

 

[mosesp]

OK, going with the following 48V AIO and battery, plus some used panels. Battery is very small, just want to get started and then build from there. Hoping this set-up works!

• Growatt 3kW 48V 80A via Signature
• LiTime 30Ah

 

[Rednecktek]

Ummm... that battery is only going to power the inverter for a day with no loads. Those inverters need about 60w per hour just to exist which is 30ah of battery.

 

[12VoltInstalls]

these might work:

• MPP Solar: 24V 2.7kW ?A

That looks good to me!

For the money, though, this could be a good choice though it’s 48V
Another at 48V and a killer price.

Not a good time for me personally to be buying stuff right now, but it looks like a good time to be buying stuff right now.
I have so much running for 12V and I have a nearly illogical aversion to running a 48V-12V step-down (something else to fail) but there’s a couple items on watts247 I’d buy right now! LOL

 

[12VoltInstalls]

Since you're making a standalone system, you don't have to worry about the N-G bonding screw stuff.

Unless you feed it a generator

Growatt 3kW 48V 80A via Signature

hmm. Link didn’t work. $$?

 

[mosesp]

OK, taking the feedback above (thanks!) I changed the approach on the battery, went with a 48V 100Ah server rack battery. More money than I expected to spend, but I have this system video walkthrough as a template, so I have a high degree of confidence that it will actually work. The last piece to figure out are the panels. I'll read the documentation on the SCC, but I think there is a minimum V level, so I suppose that will inform which panels I pick up.

 

[Rednecktek]

Yeah, on the SCC usually and in the manual there will be an entry for MPPT Range, that's going to list your min and max panel voltages you'll want to shoot for. Take the highest number and divide by the VoC of your panels. Round down and that's your number of panels in a string.

 

[12VoltInstalls]

Round down and that's your number of panels in a string.

Or round UP by one; only equatorial grazers or occasionally cold places get max label
A little overpanelled should be a benefit in most circumstances, no?

 

[Rednecktek]

No, the string voltage is based on VoC. If your math comes up with 7.57 panels you need to round down to 7 or the VoC of 8 will be a "Bad Thing" for your SCC.

When calculating how many strings you can have THEN you can round up from 2.86 strings to 3 strings and over panel a bit.

 

[12VoltInstalls]

No, the string voltage is based on VoC. If your math comes up with 7.57 panels you need to round down to 7 or the VoC of 8 will be a "Bad Thing" for your SCC.

Oh! I intellectually sidestepped the VOC reference. I was stuck on watts I guess, like watts for breakfast…. hold the smoked SCC’s

 

[Rednecktek]

Smoking a SCC should involve pecan or mesquite only. ?