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paulz
Member
# Posted: 21 Oct 2020 20:08 - Edited by: paulz
Reply 


Thanks Steve. My SCC is an Epever. What is the .3 amps below, the amount that the panels are sending the battery? Is it that low because the battery has 13.1 volts or is that all the panels are putting out (in the shade). Is the 2.5 amps what my inverter is using?
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mt50.jpg


paulz
Member
# Posted: 23 Oct 2020 10:30
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I got a bunch of these with my solar score. Finally found out what they are, just splice connectors it seems. Is that price each? Seems crazy.
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tap.JPG


razmichael
Member
# Posted: 23 Oct 2020 10:47
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Quoting: paulz
What is the .3 amps below, the amount that the panels are sending the battery?

If you have not already figured this out ...
Display Left side is the panel production and middle is the battery status from the CC. Note that 109.4V at .3 amps is 2.5A at 13.1V. So the CC controller is putting 2.5 amps at 13.1 volts into the battery. In general the CC does not really know what is being used by the inverter or DC system. Exception for DC is whatever the Load connection is using (right side of the display - 0 amps)

paulz
Member
# Posted: 23 Oct 2020 11:26
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Thanks Raz. I have been in the city last few days (that's why I'm spamming the forum ) so haven't been working on it. I figured the .3 amps was coming form the panels but didn't know at what voltage, so that helps. So the 2.5 amp reading in the bottom center is the same input just converted to 13.1v. I thought maybe it was what I was consuming with the lights on.

I have 16 panels hooked up, rather haphazardly location wise right now. 4x4 series/parallel. It looks like some are in the sun in the photo but they are not. I'm lucky to see 4 in the sun at any given time. At least I'm getting some charge to bring the batteries up while I'm gone.

I want to build some wood PV racks, been looking at examples online. Individual, so I can move them by myself.
panels.jpg
panels.jpg


razmichael
Member
# Posted: 23 Oct 2020 17:56
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Quoting: paulz
I thought maybe it was what I was consuming with the lights on.

As I mentioned, the CC does not really "know" what is being used other than it's own LOAD circuit (not sure if you have your lights running off the LOAD?"

You have had lots of great advice here (far more details than I could provide). The only thing I'll add: the whole issue with some panels being in the shade bringing down the other panels based on how everything is wired can get really complex (and may not matter if you still have enough to do what you need). But don't forget that you can split the panels into two (or more) groups and used multiple CCs - not sure if this has been mentioned?
i just added new panels and a new battery bank. I actually kept the old battery bank as a backup, added a Sunsaver DUO CC connected to the old panels and charging both battery banks (with the old being priority then switching over to the new batteries). As such, most of the time I have both CCs (the sunsaver and the EPEVER) charging the main bank and can switch my DC to the old bank if needed and then the sunsaver will charge the old bank up first next day. Ignoring the dual battery bank, the idea of multiple CCs can, in some cases, simplify the wiring, especially when you have different panel types. yes you need to pay for one or more extra CC, but they can often be reduced capacity so cheaper models are fine.

paulz
Member
# Posted: 24 Oct 2020 09:50
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I haven't used the LOAD circuit, is there any advantage to it other than the timer function?

My old Harbor Freight 150w system is still in place (the little panels in the photo) and hooked to it's own battery. I have a radio and phone charger plugged into the controller's usb ports, and still use the LED lights that came with it. Still a handy basic plug and play unit. The Epever and new panels run the inverter.

If I understand correctly, shade will bring down panels that are in series, but not panels in parallel, so if two of my four parallel arrays are in shade, the other two are unaffected. I'm not getting how a second CC changes the situation?

And yes, the advice given me here has enabled me to go from basically no solar knowledge to getting my system up and running, for which I'm truly thankful. Even if I'm not able to generate much power now, in the summer months it should do reasonably well.

razmichael
Member
# Posted: 24 Oct 2020 13:07
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Main advantage of the LOAD circuit (obviously depending on the overall system design) is that the CC will handle a low voltage situation and protect the batteries should something be left on or go screwy. I only use mine on what I consider a "Security Circuit" that powers a couple of motion sensor\s with flood lights and a couple of camera's. When we leave everything else is turned OFF but the security circuit is powered through the LOAD. I don't use the timers, just the manual setting. The capacity of most LOAD circuits is limited so can only be used for so much.

I had not noticed that you are not mixing panel types so was just suggesting the multiple CC option as it can provide flexibility, especially with mixed panels, or to provide more flexibility in how you place and group panels. In my case the older panels (320 watts 12V) can add a chunk of extra to the new ones (about 900) so it made sense to use a second CC with them. I just further extended this by using a dual battery bank CC so I could use them for both the old and new battery bank. Given how much more you have with your new panels likely not worrying about the extra 150 that could be available.

paulz
Member
# Posted: 24 Oct 2020 16:38
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Ah, good point on the battery protection on the LOAD circuit. In fact, I will test it out in a month when I put up the Christmas lights. I have been running them off a car battery and one of those chintzy 12v timers that come with unintelligible instructions. Be glad to pitch that thing.

I noticed the CC instructions say never have the panels hooked up without a battery. I use my Harbor Freight system to charge tractor batteries and unclip them to go from battery to battery all the time, doesn't seem to bother it.

OK I see what you mean about the extra CC with mixed panels and locations. I still have the 900w array on wheels I bought (first post) before these other panels fell into my lap. At some point I will pick up another CC for that, and I can put it in the yard and wheel it around for best sun.

razmichael
Member
# Posted: 24 Oct 2020 18:04
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Quoting: paulz
I noticed the CC instructions say never have the panels hooked up without a battery.

The general principal is connect batteries then CC (and reverse order to disconnect) so the CC will “know” the battery voltage (12, 24 for example) and status so, when the panels are connected the CC will not mess up the batteries with a wrong output (I’m simplifying this). Much less important for small 12v systems and I know some experts say “best to do this but never seen a problem when not followed).

paulz
Member
# Posted: 24 Oct 2020 20:30
Reply 


OK sounds right. So to charge a dead car I need to use the inverter and a standard car battery charger.

Just had a look at the Epever, blinking green bat light. Worriedly looked it up, means batteries full! First time I've seen that.

paulz
Member
# Posted: 25 Oct 2020 14:32
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Hey raz. Both my green lights are flashing once per second. Yours do that? Says charging and full in the book.
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20201025_105851.jpg


razmichael
Member
# Posted: 25 Oct 2020 15:06
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Your picture is the remote monitor but I assume you mean the actual CC? Normal - it's just 'saying" that the panels are producing power (whether much is actually needed) and the batteries are full. When you look at all the options for each LED you can tell that it is really treating each side (panels - batteries) as separate systems in a way.

paulz
Member
# Posted: 25 Oct 2020 15:17
Reply 


Ok great thanks! Yeah the CC lights. I'm leaving for a couple days and didn't want to leave hooked up if there was a problem.

Fire has been on my mind but don't hear anything about solar causing fires. Barring hoaky wiring and such.

razmichael
Member
# Posted: 25 Oct 2020 19:34
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I would think that is a very small risk (except maybe lightning). I do however turn off the master switch and only leave the LOAD circuit powering the sensors and cameras.

paulz
Member
# Posted: 26 Oct 2020 09:41
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I turned my inverter off before I left yesterday, only thing connected to the output. BTW, there must be a capacitor inside that thing, every time I have connected it, powered off, I get a pretty good spark. It can't be using that much juice powered off all the time.

So at this point the most I have seen is 4 amps at 12v (or somewhere around .5 at 108v) charge out of all those panels. That was with about the most sun I will get until spring.

The max pv watts in the Epever manual says 1,560 at 12v. With 16 260 watt panels (Pmax rating on back) I am above 4,000 . Somehow I need to figure out how to convert that into what the monitor says so if I ever approach the 1,560 I can cut out some panels. At least I have about 6 months to figure it out.

razmichael
Member
# Posted: 26 Oct 2020 10:43
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You may need to double check your max figures - not sure exactly which model you have but in my manual all the 4 series have Max PV 1560 at 24v - 780w at 12v. I think it has come up in this thread but you have a lot of panels for a (currently) small 12v battery bank. And don't forget that cold weather (granted, normally with much less sun) will increase output.
I may have missed some details as I skimmed most of the thread but I wonder if you are better only using a subset of the panels for the time being. This is also a case for multiple CCs (although you can only charge the batteries so fast anyway).

paulz
Member
# Posted: 26 Oct 2020 10:54 - Edited by: paulz
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My manual is at the cabin but here is the page out of the online manual which I believe is the same. Mine is the 40 amp.

https://www.epsolarpv.com/upload/cert/file/2003/Tracer-BN-SMS-EL-V1.2.pdf

But yes, in any case I probably should unplug some panels and see how it changes things. And btw, those MC4 connectors work pretty well. I have made up a few, easy enough, and the clips are just big enough to get your fingers in there to pull them apart without the tool.

Also, btw, I put one of the Sonny Boy grid tie inverters that came with the panels on Craigslist, I just don't see ever using them. Only hit so far was a guy wanting to know how to hook his up.. There always seems to be 2-3 for sale at any time, not much demand I am guessing. Prices from $300- $1.000, I put it at $400. Might make a good boat anchor, weighs enough.
epever.JPG
epever.JPG
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sbb.jpg


razmichael
Member
# Posted: 26 Oct 2020 12:09
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Just double check the model and version - the link you have is to older models from what I can tell (at least what I can tell from the photos in the manual). I use https://www.epsolarpv.com/upload/file/1811/XTRA-SMS-EL-V1.3.pdf

paulz
Member
# Posted: 26 Oct 2020 15:22
Reply 


Mine has the fins in front and no display, like the one in the link I posted. But I will definitely have a look at my manual.
tracer.JPG
tracer.JPG


razmichael
Member
# Posted: 26 Oct 2020 15:25
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Ok then this matches your manual link and specs. Funny that the newer ones are half the specs!

paulz
Member
# Posted: 26 Oct 2020 16:18
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Well something is amiss, I remember this from earlier in the thread. Again from the link I posted.
trac.JPG
trac.JPG


paulz
Member
# Posted: 29 Oct 2020 11:53
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I've been reading up on how MPPT works, a tough subject for someone who still struggles with Ohm's law. I read that it is very beneficial in poor conditions, like mine. Then I came across this video on MPPT testing of overpaneling in cloudy conditions, right up my alley. Can't hardly understand his English, but according to the comments it's a good thing.

https://www.youtube.com/watch?v=i-zZpf5Y7UQ

paulz
Member
# Posted: 4 Nov 2020 09:52
Reply 


"Sunshine, on my solar makes me happy..."

Been singing that lately. I may need therapy. Last week another SCC popped up on Craigslist, one exit down the highway! Yes, Renogy, I have been warned. Guy bought it for his boat, then read in the instructions that it must be installed in a dry area (apparently they sell 'wet' environment SCCs, so he said). $75, new in box, less then half price.

So I dragged some of my panel stash up to the cabin (the other solar install is at my shop down the hill) and got 6 of them cantilevered off the deck, where they do get some OK sun even now.

Hooked up and working, using 3 of those UB12500 50ah lead batteries I had kicking around. Even hooked up a 12v 2,000w inverter I also had kicking around, plugged in vacuum cleanera and 700w microwave and they worked. A/C here we come. Still in testing mode, I'm still powering the cabin with the Valence LFP batteries I charge back in the city.

This Renogy Rover has LFP charging, so I'm going to try charging one Valence battery next. Ultimately it would be great to get two hooked up and power the cabin (and carry the third in the truck for back up). With the built in protection of the Valence, I don't think they need another BMS.

Despite what has been said about the Renogy, so far so good. I will say I found the instructions more clear than the Epever, and it also has saddles where the wired attach, instead of burrying the screw into the wire. Home Depot sells these things and the reviews are mostly positive, though some say they don't last long. We'll see. But at least it got me fired up to keep this solar project going.
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Nobadays
Member
# Posted: 4 Nov 2020 10:13
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Love all your big trees but I can see they really hamper the use of solar.

paulz
Member
# Posted: 4 Nov 2020 10:22
Reply 


Yes they sure do. That's why I haven't heeded the max PV panel output specs of the SCCs. From what I understand they have internal protection and will shut down if over taxed anyway. And I am getting some usable charging. And I've gotten the panels free and the SCCs cheap enough that if it all fizzles out, mostly what I've lost is my time. I am quite used to the that..

paulz
Member
# Posted: 14 Nov 2020 14:34
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I'm going to add 3 panels in parallel, physically in line on my deck at the end of a current 3 panels. I'm assuming I can connect at least one cable at the end of the current string, as shown in this drawing. The other has to go the 25' back to the start, right?
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20201114_1124211.j.jpg


ICC
Member
# Posted: 14 Nov 2020 14:53
Reply 


Depends on the max amps flowing through that wire from the splice to the CC, taken with the wire gauge and distance for whatever the voltage is.

Steve_S
Member
# Posted: 14 Nov 2020 14:55
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This may help.
see attached image.
Panels to SCC
Panels to SCC


paulz
Member
# Posted: 21 Nov 2020 11:14
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Thanks ICC and Steve. Waiting on more connectors.

In the mean time, I have been playing with this little new controller that came with the other stuff, hoping to charge my tractor battery using an odd panel I had around.

It charges OK, this battery had 12.4 sitting voltage when I hooked it up yesterday, and by afternoon had 12.6, but overnight it has dropped down to 11.9. Not this first time it's happened with this controller. Is the controller actually draining the battery at night?
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20201121_074943_resi.jpg


razmichael
Member
# Posted: 21 Nov 2020 12:16 - Edited by: razmichael
Reply 


If the controller itself was draining then it would be unusual unless the display was drawing too much power or something internal is using power - the power needs to be going somewhere [edit: and the CC should prevent reverse flow unless broken or really bad design]. Panels generally have diodes to prevent reverse flow at night - unusual to have a newer panel without these but something else to check. I would charge the battery up during the day then disconnect at night and check in the morning to validate that the battery is not bad. You could repeat with just the CC connected at night - narrow down the problem.

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