Which way to configure panels?

[DBK]

I want to have either 6 or 8 panels, 200 watt
I have 6, 12 volt Lithium 100ah renogy

How should I configure them? Considering charge controllers which I can pick after.

8 panels @ 200 w...1600w /12v = 133.33 amp
6 panels @ 200 w...1200 / 12v = 100 amp
With a large controller

Should I....

Run 2 groups of panels and banks, with two charge controllers? Or keep one large one?

Is there better way? I can’t run them at 24v.

Open to suggestion, I also still have the choice of controllers and panels...I only have the batteries

 

[GLC]

All depends on your controller, that is where your limitations are. Controllers have limitations of volts-amps and watts.
Controllers are based on amps like 10,20,30,40,60 and so on. So amps will be one limitation. Another is volts. As an example my 40 amp MPPT controller has a 150 volt max with a 40 amp max for panel feeding but if I am running a 12 volt inverter with 12 volts of battery power, I am limited to 520 watts feeding the controller. If I bump that up to 24 volts on my batteries and 24 volt inverter, I can bump up the watts to 1060 on my panels feeding the controller. Your controller will tell you how many panels you and have on one system. Your battery voltage will be another.

 

[rmaddy]

Is there better way? I can’t run them at 24v.

Too bad. For that much solar you would be much better off with a 24V system.

On a 12V system the 6 panels with a 100A of charge current is about the max for most charge controllers. Or you could do two 50A controllers with 3 panels each (most likely in series). With 8 panels and 133A you will want two charge controllers each with 4 panels (4S or 2S2P).

Something like the Victron 150/100 would handle the 6 panels in 3S2P. You don't really need the 150V but you can't get to 100A at a lower voltage. A pair of Victron 150/60 could each handle 4 200W panels in series or 4 panels in 2S2P. A 100/60 (which Victron doesn't make) would support 4 panels in 2S2P. Two 60A controllers is of course 120A which is obviously a bit below the 133A. It's OK to over panel just a bit. You might lose out on a little bit of potential power midday but you will also get more power more of the day so it should mostly even out.

I gave examples of Victron SCCs but certainly others will work. Just make sure the temperature adjusted Voc of the panel array doesn't exceed the max PV input voltage of the chosen SCC.

Note that two SCCs can be wired into the same battery bank so you won't need two banks to use two SCCs.

 

[HRTKD]

@DBK, you may be operating under a wrong assumption. I good quality solar charge controller (MPPT) will take whatever amps/volts the PV system provides and change it into what the battery system needs. My two 320 watt panels are wires as 2s and put out about 80 volts @ 9 amps to the solar charge controller. What I get out of the solar charge controller to the battery is 50 amps at ~14.2 volts.

Your panels are actually 27 volts, not 12 volt. Four panels in series would be 108 volts 9.66 amps using Voc and Isc.

Your sample configurations put all panels in parallel which is OK to use if you think there will be significant shading. But putting all eight panels in parallel is extreme. I think you could get away with 4s2p with an appropriately sized solar charge controller. Or, you could create two strings of 4s, with each string going into its own solar charge controller. There are other configurations possible, it all depends on which solar charge controller you want to go with.

 

[DBK]

@DBK, you may be operating under a wrong assumption. I good quality solar charge controller (MPPT) will take whatever amps/volts the PV system provides and change it into what the battery system needs. My two 320 watt panels are wires as 2s and put out about 80 volts @ 9 amps to the solar charge controller. What I get out of the solar charge controller to the battery is 50 amps at ~14.2 volts.

Your panels are actually 27 volts, not 12 volt. Four panels in series would be 108 volts 9.66 amps using Voc and Isc.

Your sample configurations put all panels in parallel which is OK to use if you think there will be significant shading. But putting all eight panels in parallel is extreme. I think you could get away with 4s2p with an appropriately sized solar charge controller. Or, you could create two strings of 4s, with each string going into its own solar charge controller. There are other configurations possible, it all depends on which solar charge controller you want to go with.

I think I like the idea of

2 mini systems, of: 4 panels, to 3 battery, controller, then can I use both charge controllers on the same inverter? Or would I need two converters?

 

[HRTKD]

Think of the DC system as a bucket. The solar charge controller(s) contribute watts to the bucket. When the bucket is full, the solar charge controllers stop contributing. An inverter drains watts out of the bucket. You could have multiple inverters if you want. Systems that use multiple inverters often do so because they need more capacity (amps).

The solar charge controllers aren't tied to a specific inverter unless you buy an all-in-one that has an on-board solar charge controller.

 

[GLC]

I think I like the idea of

2 mini systems, of: 4 panels, to 3 battery, controller, then can I use both charge controllers on the same inverter? Or would I need two converters?

I have three separate controllers with 4 panels each, 12 battery bank, one 110 volt inverter and one 220 volt inverter. All works great.

 

[DerpsyDoodler]

... I can’t run them at 24v.

Why can't you run a 24v system?

 

[DBK]

Why can't you run a 24v system?

The battery’s are 12 volt only

 

[DBK]

Think of the DC system as a bucket. The solar charge controller(s) contribute watts to the bucket. When the bucket is full, the solar charge controllers stop contributing. An inverter drains watts out of the bucket. You could have multiple inverters if you want. Systems that use multiple inverters often do so because they need more capacity (amps).

The solar charge controllers aren't tied to a specific inverter unless you buy an all-in-one that has an on-board solar charge controller.

So then, I would have
4 panels into one charger, into 3 batteries
4 panels into one charger, into 3 batteries
Both those into one inverter?

Does that sound right? That’s what I am envisioning

 

[HRTKD]

So then, I would have
4 panels into one charger, into 3 batteries
4 panels into one charger, into 3 batteries
Both those into one inverter?

Does that sound right? That’s what I am envisioning

Why are you breaking up the batteries? You can pool them together as well as the solar charge controllers.

 

[DBK]

Why are you breaking up the batteries? You can pool them together as well as the solar charge controllers.

To make the charge controllers a more manageable size and cable size

I’ve been told those cables will be huge and may be too large for controllers considering the amperage

Is that a wrong idea?

 

[HRTKD]

To make the charge controllers a more manageable size and cable size

I’ve been told those cables will be huge and may be too large for controllers considering the amperage

Is that a wrong idea?

You're OK using multiple solar charge controllers. I'm not seeing the need to break up the batteries.

I have two batteries in my battery bank. I have two solar charge controllers. The batteries and the solar charge controllers are connected to a set of common bus bars. They share the circuit.

You may be making it complicated when you don't have to.

If the sets of batteries are for two completely different systems, that's a different matter.

 

[gnoeld]

You're OK using multiple solar charge controllers. I'm not seeing the need to break up the batteries.

I have two batteries in my battery bank. I have two solar charge controllers. The batteries and the solar charge controllers are connected to a set of common bus bars. They share the circuit.

You may be making it complicated when you don't have to.

If the sets of batteries are for two completely different systems, that's a different matter.