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  • #16
    Howdy all

    Sharp ND-224UCJ 224w panels are:
    Voc - 36.6v
    Vpm - 29.3v
    cells - 60
    Last edited by Cal Dan; 12-05-2017, 11:15 PM.

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    • #17
      Originally posted by Cal Dan View Post
      Howdy all

      Sharp ND-224UCJ 224w panels are:
      Voc - 36.6v
      Vpm - 29.3v
      cells - 60
      Ok, for what its worth, those aren't "24 V" panels, so you'd have a hard time getting a decent equalize from them even if your inverter could tolerate it (especially in summer, when the panels are hot). True 24 V panels generally have 72 cells, and a Vmp of 35+, a Voc of 46+. None of that matters for the problem you've described here. On the flip side, the performance hit for running those panels with a PWM controller vs mppt isn't as bad as it would otherwise be.
      CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

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      • #18
        Reading through all of this your problem is just poorly matched components. Is any one of them to blame - NO. Are they all 24V nominal - Yes (except panels but they do work good solar direct for 24v). The mismatch could just as easily be solved by using an AGM or GEL battery as there charging profile is lower than LA batteries. That would drop you below the 30V limit of the inverter and be a better match to the 60 cell panels. They would have also been a better match for you 60 cell panels. Or you could have used the PST inverter and still have the mismatch of the array.

        WWW

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        • #19
          It's an emergency system. I'd drop the charging voltage to where it doesn't trip the inverter. Check with the hydrometer to see if the batteries get fully charged, which they should if there is normally no load on the batteries. If they are getting fully charged at the lower voltage setting, your good. Done.

          If they are not getting fully charged, get a new inverter that won't trip at the higher charge voltage. Done.

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          • #20
            So Cal Dan what is the problem here?

            Set Bulk/Absorb to 29.4 volts which your panels are not capable of generating that high of a voltage under load, and set Float to 27 volts and call it done. Even better if you do not use it daily and only for emergency life gets real easy, set Bulk = Absorb = Float = 27 volts and problem solved. Turn the Inverter off when not in use.

            FWIW your battery is no longer L16RE-B, they changed the paper sticker to SPRE 06 415, and upped the price. Makes it real easy to understand. It is a 6-volt 415 AH battery.

            Get rid of the Temp Comp unless you drop to -40 degrees every night eskimo joe. As WWW points out you just screwed up and bought incompatible equipment. Stop and think what you said.
            Its an emergency system
            So WTF are you doing leaving the Inverter turned on for? When you need it, turn the Inverter on. With a load you will never get close to 30 volts even in EQ set to 32.4 volts. With a load you will not likely even see 27 volts at noon.

            You made 2 mistakes.

            1. Used GT panels with a PWM controller. You must use a MPPT controller. You can get away with what you have being a Emergency system. If it were daily use, you would never ever get fully charged. Having too many panels is not your problem, so quit wasting your time switching them on/off. Makes no difference if it is 1 or 6 panels.

            2. Bought an Inverter made for 24 volt vehicles. 24 volt vehicles charge at 28.4 volts period. and use lead calcium SLI batteries (aka Cranking Batteries) You have deep cycle lead antimony batteries.

            If you really want to fix it get a 60 amp MPPT controller and wire your panels 3S2P. Then set CC to 29.4 and 27 volts. Keep the Inverter turned off.
            Last edited by Sunking; 12-06-2017, 09:24 PM.
            MSEE, PE

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            • #21
              Thanks,

              I think I knew before I started the thread that I had made a mistake on the inverter. Hence my frustrated question "is 24v stuff 24v stuff.
              On the panels I of coarse can blame myself but I also somewhat blame the guy who sold them to me. (I don't believe they were "used". Still in boxes. Clean as a whistle)

              In your thinking of how stupid I am, try to understand that when I bought this stuff I thought of myself as sort of a pioneer of solar. It had been 25 years since I had done it, but in those days there was not the selection of equipment that there is now and not really a choice of mismatching or not. There were no MPPT controllers and when I started on this new adventure I didn't even know what one was. There was also no internet. No way of really researching anything. No info at the library. Just off grid hicks to help each other. So what I am trying to say is, though I feel pretty stupid right now I just didn't realize I now had choices. I thought 24v stuff was 24v stuff. So in reality this "pioneer" is behind your average beginner.

              Also, though I call it my emergency system, I use it for an outside fridge, washing machine, (now) xmas lights, and my entire office. Including TV, computer and ham radios. I had used it successfully only being down during equalization. Now with better batteries, a meter and temp sensor ...I can't. Frustrating. But thanks to you guys I now know my choices.

              Thanks to all, Dan

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              • #22
                Well.........

                My first choice would be to get a new inverter to solve my problem and a new MPPT controller to make things more efficient.
                Too costly for now. Probably someday since I never want to spend too much money, but for some reason am perfectly willing to spend even more in smaller chunks over time.

                What I just did was disconnect the temp sensor. Solves the immediate problem for now. I will keep an eye on the batteries and hopefully their lives will not be shortened by too much.

                On another note, if anyone would care to explain......
                all panels on, cruising along in absorption mode at 29.6v
                if I turn off 1 pr. of panels, watts going in goes up and so does the PMW % (which I am guessing the 2 go hand in hand)
                I am not saying that this is a problem. I would just like to understand why. I am guessing just leave 'em all on and fogetaboutit.
                Also I would like to know what that % means. Percentage of what?

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                • #23
                  Originally posted by Cal Dan View Post
                  Also, though I call it my emergency system, I use it for an outside fridge, washing machine, (now) xmas lights, and my entire office. Including TV, computer and ham radios. I had used it successfully only being down during equalization. Now with better batteries, a meter and temp sensor ...I can't. Frustrating. But thanks to you guys I now know my choices.

                  Thanks to all, Dan
                  73.s and you know what that means. So listen up you can make it work.

                  First if all you wanted was emergency power, you went about it the wrong way. You would not use Solar, you would make a MacGyver UPS by using a Good 24 volt Float Charger, Battery, and Inverter. That is exactly how pros do it. In addition for the extended outages of more than 2 days, use a generator to recharge. Too late for that now.

                  There is nothing wrong with your panels. In fact they are a good fit. Battery panels 18-volt Vmp cost 2 to 6 times more than Grid Tied Panels. The caveat is if you use GT panels, you must use a MPPT controller. In the end using GT panels with MPPT saves you a ton of money. With battery panels using PWM you MUST wire all panels in parallel which is the last thing on earth you want. With PWM for every 100 watts of panel wattage you only get 66 watts at best. Example a 100 watt battery panel has a Vmp of roughly 18 volts and Imp of 5.5 amps (100 watts). With a PWM controller Input Current = Output Current. Get your head wrapped around that fact because it is crucial to understanding. So at best a 100 wat battery panel can only generate 5.5 ams and not 1 mili-amp more. Ok with 5.5 amps into a PWM controller means 5.5 amps out of a controller. Do the math volts x amps = watts, or 12 volt battery x 5.5 amps charge current = 66 watts from 100 wat input.

                  MPPT Output Current = Panel Wattage / Battery Voltage. 100 watts / 12 volts = 8.3 amps. Which is the large number? 5.5 amps or 8.3 amps? Now here is where things got off track. You bought 60-cell panels as indicated by the panel Vmp voltage of 30 volts (.5 volts per cell). It takes at least 36 volts to charge a 24 volt battery, and that requires a 72 cell panels if you use PWM, or you could wire two Battery Panels in series for 36 volts. Battery panels are 36 cells or 18 volts Vmp. Understand?

                  So what can you do? Well lets start by saying what you cannot do. You cannot wire two of your panels in series to get the voltage up above 36 volts Vmp. Why? Because if you take two of your panels, wire them in series gives you 60 volts @ 7.6 amps right or 448 watts. Run that into a PWM controller and you have 24 volts @ 7.6 amps = 182 watts from 450 watts of panels. You get th eexact same amount of power if you threw a panel away. Do you have a problem with that? I hope not because that is what you are doing. With your PWM controller you have to wire them in parallel, but with only 29.3 volts you will not be able to EQ or fully charge your batteries. 29.3 is less than 30 volts of your Inverter limit. Get the picture. As long as you do not use the Inverter, 29.3 volts will get the batteries fully charged. In fact you do not even need the PWM controller to do that. You could just connect the panels directly to the batteries, but do not do that.

                  If you want this fixed is real simple. Get a 60 amp MPPT controler and rewire your 6 panels 2S3P. Set Bulk/Absorb = 29.4 volts, and Float = 27 volts as instructed by Trojan and call it done. If you do that, when and if you ever need to EQ the batteries, TURN OFF THE INVERTER.

                  In the meantime wire all your panels in parallel, and set the PWM Controller to Bulk/Absorb = 29.3 volts and Float to 27 volts as instructed by Trojan. You will not be able to EQ the batteries or go above 30 volts with the panels in parallel with a PWM controller. What it will do is allow you to operate, but it turns your 1500 watt panels into 1000 watts.

                  73's

                  KF5LJW out and clear.
                  MSEE, PE

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                  • #24
                    KF5LJW,

                    Thanks for the time explaining. Like your QRZ stickies I will have to read more than once.

                    P.S. I think you should change your golfing pic to the Texas tree trimmer pic. Remember that? Don't know if you shared it here. When I see your posts that's what I think of for some reason.

                    7 3

                    KJ6LXX

                    Comment


                    • #25
                      Originally posted by Cal Dan View Post
                      Well.........

                      On another note, if anyone would care to explain......
                      all panels on, cruising along in absorption mode at 29.6v
                      if I turn off 1 pr. of panels, watts going in goes up and so does the PMW % (which I am guessing the 2 go hand in hand)
                      I am not saying that this is a problem. I would just like to understand why. I am guessing just leave 'em all on and fogetaboutit.
                      Also I would like to know what that % means. Percentage of what?
                      Think of a PWM controller as just a rapid firing switch connecting the panels to the battery. 100% means the switch stays closed, 0% means the switch stays open, and 50% means the switch is closed half the time and open half the time.

                      The switching happens really fast on good PWM controllers, and there may be a smoothing circuit on the output so the battery doesn't actually see such sharp pulses, but let's set that aside for now. The switching is still fast enough that you can think of the output current as a time average. In other words, if the PWM is at 100% and the PV system is delivering 40 A of charge current, then at 50% it should be delivering 20 A of current. Note that the 20 A is really a time average of being *on* at 40 A 50% of the time, and *off* at 0 A 50% of the time.

                      So, let's say you've got all three pairs connected, and it is holding the target battery voltage at 50% PWM, delivering 20 A. Now, remove a pair of panels. That means that at 100% PWM, it would only deliver 26.7 A, and at 50%, it would be delivering 13.3 A of charge current. To maintain the same 20 A output, the PWM needs to increase to (20/26.7) = 75% to hold the same charge current.

                      Again, the 75% PWM cycle is really ON at 26.7 A for 75% of the time, and OFF at 0 A for 25% of the time.

                      So why do the input watts go up? What I wrote above is the ideal case in which controller efficiency is perfect, and the battery responds equally to the 40 A bursts as it does to the 26.7 A bursts, as long as they are time averaged to equal the same average current. In reality, the difference in operating at 50% vs 75% (or whatever) probably has 2nd order effects (transmission loss, battery resistance, controller losses) that make the incoming watts increase or decrease to hold what appears to be the same output. (Also assuming that the watts aren't changing because of a difference in your loads, etc). How much did the watts change when you dropped out the pair of panels?
                      Last edited by sensij; 12-07-2017, 04:29 PM.
                      CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

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                      • #26
                        sensij,

                        Thanks for the detailed explanation. I appreciate it.
                        (you could have saved time by saying that I'm on a need to know basis and that I really don't need to know)

                        Just now when I looked, watts went up 30-40. It was more like 60-80 earlier (no load change). and it seems like the other day it was even more
                        PWM % just now went from around 60% to around 85% when I turned off 1 pair
                        all with about a 160w load

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                        • #27
                          Originally posted by Cal Dan View Post
                          KF5LJW,

                          Thanks for the time explaining. Like your QRZ stickies I will have to read more than once.

                          P.S. I think you should change your golfing pic to the Texas tree trimmer pic. Remember that? Don't know if you shared it here. When I see your posts that's what I think of for some reason.

                          7 3

                          KJ6LXX
                          You mean Carl? I have a lot of Stickies here too,

                          Cal you might be chasing ghost here Not really ghost, just not understanding the dynamics. Just from reading along I do not get the sense you are working your batteries hard and led to believe that you are not using more power than the system can generate. If my assumption is correct, your batteries should be fully charged up and you just do not quite understand the dynamics of what is going on.

                          Assume for a moment the battery is fully charged, and your CC is in Float mode with 27 volts and no load. At that point you will see very little if any power from the panels. No place for power to go if the battery voltage has equalised with the charger voltage. The batteries are saturated, so no charge current flows. Now you turn on the Inverter and turn on a load. Well assuming you still have good sun light, the panels will supply the power and you will see current. Batteries are not doing anything and are Floating at 27 volts.

                          If on the other hand if the load exceeds what the panels can supply, the batteries have to make up the shortage. If that load is high enough can make the panels generate full power and still not be enough. So even when you turn off the load, the panels keep on pumping full power to recharge the batteries.

                          Here is your take away. Relax, I think you are on the right track now and not as bad as you might think. Don't get to hung up by what you are seeing. Voltage does not tell you much, but there are some things you want to see. Example 27 volts and not a lot of current flowing into the batteries means you are fully charged. The other thing is if you see the panels generating full power. That tells you the batteries are need of a charge and getting it. You should only see that in the mornings. By noon floating around 27 volts. If all you are seeing 3 to 20 amps here and there is not anything to worry about if you see voltages of at least 27 volts.

                          Only time voltage really can tell you something is a couple of hours after dark. You want to see 26.x volts.

                          73's


                          Last edited by Sunking; 12-07-2017, 07:14 PM.
                          MSEE, PE

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                          • #28
                            FWIW a comment on your Inverrter. You have a good high quality Inverter. Samlex makes good stuff. What puzzles me about Inverter Manufacturers especially those that bill themselves as Solar and Renewable Energy know or should know a 12 volt nominal battery system operating voltage range is 10.5 to 16 volts. In the case of 24 volts double that to 22/32 volt range. This use to be a problem with new Telecom equipment manufactures who must meet 32/22 for 24 volt equipment and 64/44 volts on 48 volt plants.

                            When you limit to 22/30 like you have, eliminates Flooded Lead Acid Deep Cycle Batteries because of the EQ voltage. However EQ is at most a monthly thing you can work around. Another option which is too late for you know, but if you had used AGM batteries, is perfect for that Inverter. AGM max charge voltage is 28.4 to 28.8 volts well withing the 30 volt limit. My best guess is they are following auto manufactures lead. If you have noticed a trend over the years, AGM batteries are taking over the Auto Market. Reason is simple is because cars electrical systems need a lot of power for all the electronics today and near future EPA mandates that your car engine shut off while stopped at a light. You need a hefty battery to keep the heat on with the stereo blasting and still have power to start the engine when you press the gas pedal.

                            Lastly if you are not using your system much, you should have no issues keeping the battery charged up. You should be able to just FLOAT it at 27 volts and forget about Bulk/Absorb. I have 12 volt system on my rig. All I use is my Astron PS set to 13.5volts and float my batteries 24 x 7 x 365 like every communication pro does. No pro use 3-stage charging, it wears the batteries out going above 13.5 volts Only thing 3-stage charging is used for is fast charging when used daily. Trade off is shorter battery life.

                            Hope that helps clear things up.
                            Last edited by Sunking; 12-07-2017, 08:57 PM.
                            MSEE, PE

                            Comment


                            • #29
                              All very interesting. I'm catching on to some stuff that not only I didn't know, but didn't know that I needed to know
                              and I'm OK now that I understand a little more.
                              I think part of it is the miner hording tendencies in me don't want to let any watts go to waste.

                              I do agree about the emergency aspects. I have a nice quiet little Honda 2000 and have planned for a while now to get a 24v charger.
                              Still like having the panels.

                              A note on the L16RE-B / SPRE 06 415
                              I was going to get the SPRE's but they weren't available yet. I got the L16's suspecting that the SPRE's were the same with new name and probably higher price.
                              I inquired to if they are the same why do the SPRE's have slightly better specs? Answer: specs done at different temperatures.... But still exactly the same batteries.

                              Texas Treetop Trimmer


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                              • #30
                                Originally posted by Cal Dan View Post
                                A note on the L16RE-B / SPRE 06 415
                                I was going to get the SPRE's but they weren't available yet. I got the L16's suspecting that the SPRE's were the same with new name and probably higher price.
                                I inquired to if they are the same why do the SPRE's have slightly better specs? Answer: specs done at different temperatures.... But still exactly the same batteries.
                                Exact same battery. Only the stickers, test parameters and price has changed. What you really want to know is look at the Battery Term Post, they tell you everything you need to know. The negative post tells you when it was shipped from the factory. The Positive post tells you when the battery was activated by the distributor.
                                MSEE, PE

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