Am I on the right track?

[AzRoute66]

[...] BTW, what's the purpose of the shunt? I have not hooked up the charge controller or the panels yet as I'm a little confused on where to wire the charge controller on the battery bank.

The shunt is a very small known resistance, by measuring the voltage on it the current can be calculated. I = V/R. Knowing your current is essential to knowing your power/wattage.

From the picture, I believe you have an incomplete knowledge of the shunt/meter. You will want three wires to go from the battery bank to the meter. None of these wires carry current, so they can be MUCH smaller that what you are using, like telephone wire or ethernet cable. You will want that as you want to place your meter in a convenient place to see it, not where the nasty batteries hang out. I put my meters in a box with a female phone jack, and mounted a female phone jack in a plastic conduit box that holds the shunt. So the shunt has two small signal wires attached, and the third is attached close to the positive battery terminal post, exactly where will be largely determined by the physical layout. The only thing is not to get the positive battery voltage way downstream from the battery, like from some odd power wire near where the meter is mounted, I see that a lot - very bad. So, by using a 20' phone wire I can have the meters somewhere where I am a lot, and if I want to take it to the batteries for some reason, I can just use a separate 3' cord... At any rate, by jumpering terminals 2 and 3, you don't have to run a fourth wire - you can confirm that on your hookup diagrams. The diagrams will be showing how to connect to either measure charging watts or discharging watts, know that if you swap the shunt wires you will be measuring the other. In my setup, I have one meter to measure one, and one meter to measure the other, using the same three wires, in the same box - a poor man's bidirectionality.

My questions are, where does the charge controller hook up? Also, I'll attach a picture of the 'connector hoyahs' for the panels. How do those plug in to run the panels in series to the charge controller AND, how do you get from those connectors to bare wire to connect them to the charge controller?

The charge controller and inverter cables should be bolted to each other, usually via a hefty terminal strip or bus bar. The positive side will go to the battery via the fuse, the negative to the battery via the shunt. Nothing should be connected directly to the battery terminals except the wire to the fuse, and the wire to the shunt.

[RiP-HS-]

[QUOTE=AzRoute66;n362413] I shouldn't have been quite that quick, I have changed my mind on this. I think your sustaining configuration will be to have two of the panels primarily on the 12V system as it will have the most usage, then to take one or both of the panels OFF of the 12V system when you want daytime running of the inverter. Do you see where I am going with this, and is my assumption that the inverter could be infrequent 'daytime' use be correct? Or, all of that 12V stuff you charge might be charging off the inverter, and if that is the case I don't know why you want a 12 V system at all...

Correct.

The minimum would be AWG #10, this might change with your answer above, but larger would be fine up to the capacity of the terminals on the charge controller.



The Tracer seems a good enough choice, you can put two of your panels in series on it. I'll double check the temperature later. You can only use your PWM controller if it is 24V system capable, you cannot use it on the 12V system with those panels. If it is 24V, it is not out of the question that it can be well utilized on your 24V system if we make you something that we want to use all three of the panels to power the inverter as described above. Any info on the PWM controller? And, of course, info on the inverter can't hurt. Again, if it is a 12 V PWM it cannot be used in any way with these panels to the best of my limited, and frequently corrected, knowledge. Finally, just to double check, the PWM is the 20A charge controller you listed in post #1 (erroneously as MPPT), not a third charge controller?

The PWM is a third CC. The 12v inverter is a PSW Gowise PS1004 3000w


Could you share what you can or cannot get? For instance, it doesn't seem impractical for me that you could return a brand new 12V PWM controller for another MPPT or 24V PWM, but that might not be the case. How hard to get an extra panel? two more batteries? a different fuse? different wire? If we assume we only have the MPPT Tracer, to what extent will somebody be around to swap a few wires for 'inverter times'? Having only one operational charge controller is going to be a bit of a bottleneck. I get the sense that you have not yet taken delivery of all of the items from your Atlanta shopping spree?

I do have another small MPPT CC MPT-7210A which I believe is a 20a to be used on the single panel going to the 12v system. Unfortunately, it'll be near impossible (or at least uneconomical) to get another panel like the ones I have and I would for sure have to ship it here. Batteries, on Island, are a hot commodity at the moment... To be honest, I'm kinda stuck with what I have. We shipped three flat rate boxes full of dry food type stuff to ourselves three weeks ago and they haven't arrived yet and may never. Since Puerto Rico got hit I think some of the USPS packages are not making themselves here as they stop in PR first either by being grabbed there or disorganization. My wife and I both work all day, so there will be no swapping wires. Once I get the 24v up and running, I'll get a good inventory of all of the left over components and see what can be done with them.

I was in a bit of a frenzy thinking of lighting and went a little crazy buying Ridgid and Dewalt batteries and lights so now I'm somewhat reliant on 120v to charge them. I'll visit a couple of marine stores and see what 24v and 12v led stuff they have so I don't have to go from DC to AC as much.

Sorry for any typos and the formatting, I'm doing this from my phone.

Thanks,
Gabe

[RiP-HS-]

This is the shunt and power meter.... With one small 120v w/transformed led desk lamp. This meter is in addition to a remote panel for the tracer charge controller. Will the charge controller deliver redundant information.? The charge controller did not come with a shunt, it came with the little display meter in the picture.

[AzRoute66]

Hmm. I would have thought that the charge controller came with an MT-50, and that meter came with the shunt. I'll get back to you when I have time to look up that charge controller.

[RiP-HS-]

You're correct, I must have typed wrong. The CC came with MT50 but how would it display the same info as the meter w/o the shunt?

I meant the shunt came with the meter.

[AzRoute66]

The charge controller (and thus the MT-50) cannot control the charge on the battery, or even have a clue what it might be, because the loads, including inverter, are bolted to the battery, bypassing it. This is a separate rant of mine that shouldn't be re-ignited here. The 'energy' meter with shunt, is only concerned with the charge going in and out of the battery, which is what one would ignorantly think that a 'charge controller' should be doing (ARGH !!!). Unfortunately to some, but fortunately in my little opinion, these cheap meters only measure power one way, so you need two of them to measure both power in and power out.

I understand that some charge controllers DO have a shunt, the majority apparently do not.

That is not to say that one meter is not useful. If I only had one meter I would measure only discharge. That way you can identify any extraneous or ill-behaved loads, even when the little woman hits the 'heated dry' button on the dishwasher, which she said she wouldn't (another separate rant).

[RiP-HS-]

Well now I'm even more confused. Your first sentence has my mind boggled. So if the charge controller can't see the status of the battery bank then how can it do the charge controlling?

Does the charge controller hook up to the shunt on the main lug closest to the battery bank on the negative side and on the fuse side (from the inverter) closest to the battery bank (effectively bypassing the fuse going to the battery) therefore the one fuse on the positive side from the charge controller protects the charge controller itself?

[AzRoute66]

Well now I'm even more confused. Your first sentence has my mind boggled. So if the charge controller can't see the status of the battery bank then how can it do the charge controlling?

Exactly. It can't. It gets power from the panels, and makes it available to the battery and loads, if the battery starts accepting it, the battery is charging.

If the battery starts accepting a lot of it, the battery is said to be bulk charging, and the controller will supply as many amps as it can (up to the bulk charging limit, usually the amperage rating of the controller, but sometimes a programmed limit). By definition, it will stay in bulk charging until such point as the battery won't take all of the current offered. This transition will always occur when the system voltage has risen to the 'Absorb' setpoint.

As the batteries charge, the voltage on the terminals (and at the controller) will rise. When it has risen to a certain limit, called the Absorb or Boost voltage setting, the 'controller' will lock it's voltage at that value, and let the battery continue to accept whatever amperage it will from that set voltage. This is known as the Absorb or Boost phase, and the amperage will taper off the closer the battery gets to full charge.

When the battery is so charged that the current is very small, the controller will change its set voltage to the Float value and continue to let the battery sip any sustaining current from that. Some controllers have a timer which will also end the absorb phase (change the setpoint to Float) for situations where it does not terminate naturally.

Note that while all of this is going on, if loads are applied, they will steal that amperage away from the battery and the controller knows nothing of these indiscretions, even if they totally interrupt the bulk or absorb charging processes.

But, at some point, maybe days/weeks later, the charge controller is right where we started, sitting at Float voltage, ready to make available whatever power it has to anything that wants it, be it battery or load.

Does the charge controller hook up to the shunt on the main lug closest to the battery bank on the negative side and on the fuse side (from the inverter) closest to the battery bank (effectively bypassing the fuse going to the battery) therefore the one fuse on the positive side from the charge controller protects the charge controller itself?

It is worth repeating: "The charge controller and inverter cables should be bolted to each other, usually via a hefty terminal strip or bus bar. The positive side will go to the battery via the fuse, the negative to the battery via the shunt. Nothing should be connected directly to the battery terminals except the wire to the fuse, and the wire to the shunt."

[RiP-HS-]

AZ, Thank You that explained a lot!

My final question...for the night...

The fancy connectors for plugging the panels together, should I just cut those buggers off and twist/Solder them in series and add to the CC?

Thanks Again, you have been a huge help. Tomorrow, I'll wire the rest up and send photos of the finished product if you care to see.

[AzRoute66]

The fancy connectors for plugging the panels together, should I just cut those buggers off and twist/Solder them in series and add to the CC?

The definitive answer is 'occasionally'.

The connectors on the back of the panels should be plugged into each other when connecting panels in series. If you have a 'row' of panels, that will leave you with a positive connector at one end of the row, and a negative connector at the other end of the row. This row of series connected panels is called a string. If you are connecting your panels (or strings of panels) together in parallel you will need to connect the positives together and the negatives together. There are plastic unions with the same type connectors made to do just that if the ends of the panel wires are close enough together, which usually they aren't. So we would use a cable with a connector at one end and bare wire at the other. The bare wire would go to the controller, either directly, or by 'combining' them with other bare wires in a combiner box, and a totally separate wire going from there to the controller.

Many times, a 10' wire is needed to get from the near side of the 'row' to the combiner/controller, and a 40' wire is needed to get from the far side of the row. In that case our diligent installer buys a 50' 'extension' cord, and cuts it in the appropriate place and has both, each with the factory installed correct connector at the end to do the job.

Hope that helps, it's all I got without looking exactly at what might be in your pile of stuff. And if it wasn't clear, never cut the connector off of a panel wire, if you want a bare wire right at that location, put a mating connector on a 8" chunk of wire and use the end of that.

Thanks Again, you have been a huge help. Tomorrow, I'll wire the rest up and send photos of the finished product if you care to see.

Certainly. Looking forward to it.

[AzRoute66]

Here is a photo of a recently installed system very similar to what you are doing. This was stolen from another thread in the dead of night from Carv , with all due apologies and/or congratulations. Let's look it over. image_10129.jpg




1. The negative from the battery comes up from the bottom of the picture and goes straight to the shunt. We can presume that nothing else is connected to the negative battery terminal.
2. The Energy meter is connected to the positive (by the mid-size red wire) as close as possible to the positive battery terminal (also coming up from the bottom of the picture) without being connected to the battery terminal. This wire is protected by a small inline fuse, a nice touch.
3. The red fused wire picks up the three shunt wires off of the shunt (would be two wires if he used the jumper terminals 2 and 3 option) and goes through a small flexible cable with even smaller wires to someplace where the meter(s) can be easily seen, probably through walls and under floors and onto his home office desktop, or better, next to the television. (sorry, that was a reflection of me, not him).
4. Back to the battery negative. It leaves the shunt and goes directly to the inverter and the charge controller. Boom, negative done.
5. The positive from the battery comes up from the bottom of the picture to the fuse. It goes (pre-fuse) to the breaker box, then out of the breaker box on the red wire at the top of the box to the charge controller. The breaker will be large enough to handle the charge controllers amperage rating, but small enough to protect the wire between the two. We can presume nothing else is connected to the positive battery terminal.
6. The other side of the battery fuse goes directly to the inverter and also branches out of the picture at the top. A 'mystery cable'. We can presume that is either a DC power distribution or it is another inverter, as it has roughly the same gauge wire as the 1500W inverter does. That fuse is larger than the 1500W / [system voltage] = X amps, (plus anticipated surge) [and perhaps whatever is at the end of the mystery cable] but small enough to protect the wires.
7. The panel negative comes from the combiner box through the black wire at the top right of the picture and straight to the charge controller.
8. The panel positive comes in at the same place and goes into the breaker box on the gray wire, and comes out the side of the box on a red wire and straight to the charge controller. The breaker will be large enough to handle N x Isc [temp corrected] amps but small enough to protect the wire. N = the number of strings of panels.

How simple. And in this case, how clean and elegant. If your first install is even half as tidy tell your wife that you qualify for $1000 more solar gear.

Hopefully you can use this to answer many of your upcoming installation questions, or at least provide a reference to ask some of them.

Again, sincerest apologies to Carv for not asking first. Here's hoping this picture stays intact.

[AzRoute66]

The 'quote' function is apparently broke, so it is old school: You said, "The fancy connectors for plugging the panels together, should I just cut those buggers off and twist/Solder them in series and add to the CC?"

And I said, not even remembering your second picture I was so busy with the first, I said, "If you are connecting your panels (or strings of panels) together in parallel you will need to connect the positives together and the negatives together. There are plastic unions with the same type connectors made to do just that if the ends of the panel wires are close enough together, which usually they aren't."

Well, that is exactly what you have in the picture. Those unions are for putting up to four strings of panels in parallel. Remember, a string can consist of one panel. I can think of no reason to cut one up. These would normally be used with four MC-4 fuseholders, keep that in mind if you decide to use them in the future.

Speaking of which, last I knew, you were going to make the best of your 36V of batteries, and three panels, by making one 24V and one 12V system. Is that still the plan? I ask because if you decided that the 12 V system was superfluous it might be a good experiment to use those unions to put all three of the panels in parallel on the 24 V system.

[RiP-HS-]

Hello AZ,

A brief overview of what's going on...

I have six 6v 110ah (the guy said they are trojan t150 w/ 'Battery Source' stickers on them) funny thing is, I thought it had specifics on the battery but I don't see them now. The name brand is Golf Pro Xtreme from 'battery source'.

I also have the three 325w mono panels which the specifications are listed in the first post or two of this thread.

A 24v 2000w inverter and a 3000w 12v inverter, the MPPT Tracer 30a CC for 24v and a Generic 20a 'Chinesium' MPPT CC for the 12v. I also have a PWM CC that I bought ignorantly.

My plan after reading everyone's opinion from here was to use four of the batteries for a 24v and two for a 12v as I'm missing components to do better either way. I'm missing a panel or missing two batteries. So I think I'll do a 12v to charge phones, run a few lights and run a small 12v pump for showers and pulling water from the cistern for dishes, coffee, toilets, etc.

Would there be an advantage to running the two panels in parallel vs series as I'd only have two for the 24v system. I, fortunately, work where I can get wire so the size and my small runs will not amount to much.

I can already see that cable management is going to be key, my house is already wired for 110v, I know I don't have enough storage to wire directly to my transfer switch (where an old generator used to be). I guess I'll have to string a bunch of DC stuff around to make things convenient as there are only 2 110v outlets on the inverter. Any suggestions?

We went out after work tonight so I didn't get the chance to do anything with the solar stuff, I've had a few drinks and I'm not ready to start messing with it now.

I really appreciate all of your help and the time you have spent helping with this, I'd like to buy you a few drinks sometime!

Once I get the 24v stuff working which should be tomorrow evening after work, I'll list all of the leftovers for the 12v stuff.

*edit*

The 24v will have two panels (series or parallel is the million penny question) and the 12v one panel.

[RiP-HS-]

I appreciate the picture from the other post, it'll give inspiration for sure. I'm a little limited on what I can source, locally, so I'll have to make do with what I have. It's not going to be as pretty as his but it'll be functional.

[AzRoute66]

My plan after reading everyone's opinion from here was to use four of the batteries for a 24v and two for a 12v as I'm missing components to do better either way. I'm missing a panel or missing two batteries. So I think I'll do a 12v to charge phones, run a few lights and run a small 12v pump for showers and pulling water from the cistern for dishes, coffee, toilets, etc.

I would try that first too. If you have a hard time charging the 24V system, just keep in mind that it would probably be a good fit to use all three panels in parallel (with your 4-1 branch connectors) and it MIGHT get you more/faster charging at the expense of 'losing' the 12V.

Would there be an advantage to running the two panels in parallel vs series as I'd only have two for the 24v system. I, fortunately, work where I can get wire so the size and my small runs will not amount to much.

Not that I can see. I would put the two panels in series.

I guess I'll have to string a bunch of DC stuff around to make things convenient as there are only 2 110v outlets on the inverter. Any suggestions?

Nope. Bear in mind that you are not looking for permanency in your situation. Extension cords and power strips and whatnot are probably the order of the day.

There must be a traders market for the solar stuff given the situation there. I would try hard to peddle that 12V 3000W inverter for another panel or a couple batteries. Throw in that PWM controller if they deliver.