Newbie with multiple questions

[Austinbriggs123]

Ok so I’m new to this so don’t roast me!!! Haha just kidding
I’ve decided to go with a 1000w system
My list I have some things are not adding up I don’t think but tell me if it will work.
4 250w solar panels. That run with a (vpm) 34v I will need to run them in series solar array will be 100yrds from battery controller. So I will have 136v once all connected together?
Charge controller is a 60a CAE mppt
Here’s where I’m confused
Specs say recommended input voltage
12v(18v-60v)
24v(36v -72v)
48v (72v-144v)
I don’t really have the money to buy 4 batteries to make a 48v system nor do I want to. So my panels in series would be just under the 48v limit of 144v max.
I have a 100ah 12v lithium battery
Also I have a 2000w-4000w peak pure sine wave inverter please help! Im getting overwhelmed with this whole thing haha I have not purchased the panels yet they are just a killer deal at 100 bucks each.

 

[John Frum]

@Austinbriggs123 what is your question?

 

[Austinbriggs123]

@Austinbriggs123 what is your question?

I do t think what I have will work will it? My solar panels in series will produce 136v on the specs of my charge controller it says recommended voltage for 12v is 18v to 60v?

 

[Rednecktek]

OK, so here's a few tips to hopefully help:

The number you need to use for your PV voltage is the VoC, not the Vmp.

If you're going to be using a 12v system then your panels will have to be in parallel to avoid over-volting the charge controller. That should put you around 37-ishVoc and 28a which is about the top end of MC4 connectors. Putting any of them in series on a 12v system will fry the controller. Fortunately you can get 4-way MC4 splitters pretty cheap, just plan on running 10AWG wire from the splitters to the SCC.

That 12v battery is pretty undersized for a 2000w inverter. At 2000w that's about 30 minutes of run time and 170amps of wire and fuses. Most people would say drop that down if you can or bump up your battery bank to a higher voltage.

 

[Porch]

Based on my quick look, the input voltage is the recommended range. I don't see where it says it won't work at a higher voltage. That said, 12v times 60 amps is 720 watts. So with 1,000 watts, you will have more watts then that controller is rated for at 12V. You will have no room to expand.

Also, $100 for a 250w (40 cents a watt) panel is an OK price for a new panel. A poor price for a used panel. I regularly get used panels for 25 cents a watt, or about $100 for 350 watt panels.

 

[Rednecktek]

Yeah, I ran into the same thing with my MPPT controllers, the working voltage is rated by the size of the battery bank on the cheaper units. So while it SAYS 150v that's only the maximum-won't-catch-on-fire voltage and only for a 48v system.

 

[Austinbriggs123]

Yeah, I ran into the same thing with my MPPT controllers, the working voltage is rated by the size of the battery bank on the cheaper units. So while it SAYS 150v that's only the maximum-won't-catch-on-fire voltage and only for a 48v system.

So if I get a more expensive controller I may be able to run on a 12v setup?

 

[Rednecktek]

You can run on what you have, you just have to set up your panels in a 4p setup. You could replace the controller and try to find something that would let you kick up the voltage, but you're still going to have the same panel output and battery capacity.

 

[Austinbriggs123]

Based on my quick look, the input voltage is the recommended range. I don't see where it says it won't work at a higher voltage. That said, 12v times 60 amps is 720 watts. So with 1,000 watts, you will have more watts then that controller is rated for at 12V. You will have no room to expand.

Also, $100 for a 250w (40 cents a watt) panel is an OK price for a new panel. A poor price for a used panel. I regularly get used panels for 25 cents a watt, or about $100 for 350 watt panels.

I could possibly run a 24v battery bank just more $$$ but if I upgrade to a 80a charge controller it’s more $$$ as well haha. Have you ever heard of someone running 100yrds with solar array in parallel?

 

[Austinbriggs123]

OK, so here's a few tips to hopefully help:

The number you need to use for your PV voltage is the VoC, not the Vmp.

If you're going to be using a 12v system then your panels will have to be in parallel to avoid over-volting the charge controller. That should put you around 37-ishVoc and 28a which is about the top end of MC4 connectors. Putting any of them in series on a 12v system will fry the controller. Fortunately you can get 4-way MC4 splitters pretty cheap, just plan on running 10AWG wire from the splitters to the SCC.

That 12v battery is pretty undersized for a 2000w inverter. At 2000w that's about 30 minutes of run time and 170amps of wire and fuses. Most people would say drop that down if you can or bump up your battery bank to a higher voltage.

I plan on adding batteries in the future probably 3 in total. I just don’t have the cash to buy 3 now and I’m wanting to get this going before there is a shortage on stuff haha! And my normal power consumption will honestly only be 200watts a hour I’m just wanting to over size it just in case I end up running tools or something out there some days

 

[Porch]

I plan on adding batteries in the future probably 3 in total. I just don’t have the cash to buy 3 now and I’m wanting to get this going before there is a shortage on stuff haha! And my normal power consumption will honestly only be 200watts a hour I’m just wanting to over size it just in case I end up running tools or something out there some days

200watts an hour? 24 hours a day? If so, that is quite a bit of power for your smaller system.

 

[Rednecktek]

You could use your current panels and controller in a 2s/2p setup if you go 24v. You'll need a 24v inverter to do that, but if you have the cash it'll buy you a bit more capacity. There's no need to upgrade the SCC if you don't need to, the 60a is how much the SCC can feed to the batteries, so even with a 4p setup you're looking at 35a-ish.

And yes, since each panel will only be producing about 8a, you can run 10AWG from the panels to a bus bar right at the SCC and then the thicker wire the few inches from the bus to the SCC so line loss will be almost nothing. 10AWG is what most MC4 connectors use anyways and it's rated for 30a.

If you do a 12v system now you can always parallel batteries in later for more run time.

 

[Austinbriggs123]

You could use your current panels and controller in a 2s/2p setup if you go 24v. You'll need a 24v inverter to do that, but if you have the cash it'll buy you a bit more capacity. There's no need to upgrade the SCC if you don't need to, the 60a is how much the SCC can feed to the batteries, so even with a 4p setup you're looking at 35a-ish.

And yes, since each panel will only be producing about 8a, you can run 10AWG from the panels to a bus bar right at the SCC and then the thicker wire the few inches from the bus to the SCC so line loss will be almost nothing. 10AWG is what most MC4 connectors use anyways and it's rated for 30a.

If you do a 12v system now you can always parallel batteries in later for more run time.

ok I’m looking into a 24v system now but even with a 24v system. I’m running the 144v to the charge controller I can’t even find a controller that can handle that many volts with a 24v battery bank.

 

[Rednecktek]

Not quite, in a 2s/2p setup you would be running whatever the VoC of 2 panels adds up to. Series adds voltage, parallel adds amperage so 37v+37v=74v per pair. When you put the pairs in parallel the total voltage will still be 74v but the amperage will be double whatever the panel says it puts out.

Mind you I'm guessing on the VoC and Imp on those panels.

 

[Austinbriggs123]

ok I’m looking into a 24v system now but even with a 24v system. I’m running the 144v to the charge controller I can’t even find a controller that can handle that many volts with a 24v battery bank.

I guess I don’t understand. I was told I can’t run parallel because my panels will be over 200 ft from my controller.

Not quite, in a 2s/2p setup you would be running whatever the VoC of 2 panels adds up to. Series adds voltage, parallel adds amperage so 37v+37v=74v per pair. When you put the pairs in parallel the total voltage will still be 74v but the amperage will be double whatever the panel says it puts out.

Mind you I'm guessing on the VoC and Imp on those panels.

that sounds like a plan lol. You think that would have enough juice to run 200ish feet also what size wire would you recommend I run out of the panels to the CC?

 

[Rednecktek]

I'd roll with 10AWG wire since 1: it's readily available, 2: it's what the MC4 connectors are designed to use, and 3: Gives you plenty of headroom for the low amperage you'll be pumping down the lines. At 6a and 200ft you're only getting a 4% voltage drop which is perfectly fine if not ideal.

Whoever told you that you can't parallel was probably assuming that you'll be running all the wires together THEN running the 200ft. If you do that then you're doing 36% voltage drop which is horrible!

If you run the 200ft first THEN bring them together at the SCC you'll be fine. If you can start out at a higher voltage (and here's where the series connection comes in) you gain a bit less line loss.

There are other advantages to running series panels like your MPPT controller having more to work with to start charging up the batteries earlier and charging longer. Do you know how that works?

 

[Austinbriggs123]

So I would run it like the picture below.
Then out of the panels run 2 10gauge wires one positive one negative 200ft into the charge controller? Correct

 

[Rednecktek]

Close. You've got the panels connected up right to each other, but don't connect the panel strings until the charge controller. See bad MSPaint attached. If you connect it up as you have it there and THEN run the 200ft of wire you'll be pushing 14a (9%) through the wire instead of 7a (4.5%) which results in about double the loss.

 

[Austinbriggs123]

Ok so once at the cc do something like this I didint even know what a bus bar was… I’m a newbie. Also what gauge wire would u use after the bus bar to the cc

 

[740GLE]

Running two parallel strings 200ft to be combined at the SCC is quite a bit of extra conductor.

What’s cheaper one run of larger conductor or two runs?