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  • Built A tiny home, but it has solar issues

    EDIT I AM REPOSTING THIS , so people have a clearer idea of my setup and what I am trying to accomplish. I hope this helps. If you reply to this please do so with quotes so I can answer any pertinent questions.



    Current Tiny Home Solar Summary

    2 6 volt deep cycle Interstate L -16 400AH Batteries
    1 325 watt solar panel (specs based on invoice appear to be 39 1\2” X 72”, amps unknown)
    1 100 Watt solar panel (unknown specs but believed to be a mismatch to main panel)
    1 SCC (based on invoices) MPPT version made by PowMr 60 amp
    1 EDECOA 3500 Watt Rated/7000 Watt Surge Pure Sine Wave Inverter

    Known Conventions.

    The SUV (Tow Vehicle) is running a HORSMILE 12V 140Amp Isolation system from the main engine compartment to the rear of the Tow Vehicle. This system is powering an “auxiliary feed” that sends 14.4 volts to the tow vehicles 7 way harness when the main vehicle battery is charged. This system then runs through the 7 way blade harness and is then linked to the two 6 volt batteries mounted to the tongue of the tiny home. This system is self contained and sends charging voltage to the batteries during long transits, the system is not tied to the main tiny home system and the leads end at the batteries.

    The main panel and “helper” panel is connected together on the roof of the tiny home. They are connected in parallel using an MC4 Waterproof connector then the power is run across the roof conduit to the command center wall located in the tiny home. The solar input then runs into the SCC (As listed above) and is then routed to the WFCO 30 amp power center.

    The inverter receives its power from the batteries on the tongue by way of a pair of heavy duty cables. Negative power is routed through a shunt then sent to the inverter. The positive cable is routed through a 300amp fuse block and then to the inverter, which also has a cable running to this same point from the SCC. Also on the shunt are the monitor cables for the solar system. This monitor only has ever displayed a continuous count of one value, and does not seem to be recording a SOC properly. The inverter has a remote start panel that is also wired to a conventional “rocker light” switch, and this is installed for safety reasons when a backfeed is taking place. More on that below.

    The WFCO center powers the DC as well as the AC circuits in the tiny home. The main fuses of the WFCO panel are shared between a breaker for the inverter power (which comes from the solar) and a separate breaker for “shore power”.
    When the “shore power” (which is wired from an outside 20amp weatherproof plug) is activated, a hidden switch is used to disconnect the solar. This is done to eliminate damage to the inverter. While shore power is activated, a 30 amp backfeed routes through the WFCO and into the batteries.

    The batteries powering the solar system have three points of charging, From the solar power of the panels and then through the SCC
    From shore power circuit activating a backfeed to the batteries that is controlled by the WFCO
    From the isolation systems on the tow vehicle when in transit

    Known Issues

    As of right now the system is “dead”. The batteries are completely depleted and I suspect they are frozen. I read something about a battery being discharged being prone to freezing if the acid content is to low. It is unknown if the batteries can be saved.
    The solar panels continue to function but it is now believed there is a “mismatch” in these two collectors.
    The internal system continues to work if shore power is switched on and a generator or external power source is wired to the tiny home.

    [Possible Solutions

    Suspicions now lie in the system not being setup properly. The solutions will depend on a proper energy audit being done to determine the needs of the system.

    Possible solutions could mean new or changing configuration of panels, adding external panels “suitcase” to augment the current configuration. Completely replacing the batteries with lower amps, different voltage, AGM style, etc.

    Limitations

    My lack of knowledge in this area, going back to the installer is NOT an option. I would rather learn all I need to and do it right. The panel space on the Tiny home is extremely limited, any changes will require extensive new modifications. Mismatched panels and possibly dead batteries.

    A further additional concern is partially unrelated to the solar, but will also have new design ramifications as well. The batteries for the solar configuration are mounted to the sides of the tongue of the trailer. This area needs to be repurposed to install a weight distribution hitch system to make towing the tiny home safer for the tow vehicle and the trailer. Any new battery configuration will require relocation, optimally inside the tiny home but I have been told this is only possible with AGM as they do not need to vent.

    I hope this primer allows people to better understand my situation, I will accept any feedback and suggestions, but I want to make it clear that permanent mounting systems will not work, as this is a mobile installation.

    Thanks again









    ORIGINAL POST





    Preface: I tried to post this on Reddit, but I found that place to be run by juveniles and "apes" as they liked to call themselves. I figured I would take my issues to a place where people could at least speak proper grammar!

    Hi there,

    During this crazy pandemic I went to Utah and along with a good friend I built a THOW (tiny home on wheels) out of a 6X12 cargo trailer, and no this is not a joke.

    I hired a man from hurricane Utah (pronounced hurricann) and the goal was to make the unit totally see contained.

    Unfortunately after spending large amounts of money and time , I feel that some things were left out of my build. My goal here is to talk to like minded people to see if I can flesh out the issues, and when summer returns work out the bugs.

    I will start by saying I have a 2 panel system on the roof , one panel is 4’ X approximately 3’, and it’s helper panel is a 2’ X 2’ , again approximate measurements only. The total wattage is not exactly known but it all runs into a joint cable and down into the solar controller. On the front of the trailer are two large 6 volt/220AH interstate deep cycle batteries. The batteries were brand new in September 2020, and they are already stone dead.

    I want to point out that this system never worked properly and returning to where it was assembled is not an option. I’m hoping some very smart people here can help me sniff out the issues.

    I am going to start by contacting interstate about getting new batteries. I didn’t want to list to much here at first, but would be happy to go into it in detail should anyone want to help.

    Thanks for your time.

    (PS) the photo in this post is the "command center wall" of the tiny home.


    The_realTW

    solarwall.jpeg
    Attached Files
    Last edited by The_realTW; 02-16-2021, 09:45 PM. Reason: Clarification on my current setup and needs

  • #2
    Without knowing the panel wattage or their Imp rating it is hard to say if they were enough charging amps to keep your batteries happy. A 12V 220Ah system would need between 18 amps and 27 amps of charging.

    Also that inverter can be a significant drain on the batteries just being turned on without any load connected.

    Finally if you have any idea concerning what you would use in watt hours in a 24 hour period that would help determine if your batteries were sized properly.

    A solar / battery system requires a balance of wattage, charging amps, and battery size to keep it healthy. It sounds like your system is lacking something.

    Comment


    • #3
      Hello TW.
      Sorry about your problems. As SunEagle indicates, we need specifications as to what you are working with. If you look on the back side of each solar panel, you will see a label with specifications like Vmp, Voc, Imp, Isc. We need to know what those specifications are? We would also need to know how these panels are wired into your charge controller, which is the black and white box in the upper right of your photo.

      I'd guestimate that your large 4'X3' panel is a 250W grid-tie, running at 30VDC. The 2'X2', I don't know, that's really not a standard size. Let's take a guess and say it's a 12V 150W panel? I would suspect that they are operating at two different voltages? Do you have a voltmeter/multimeter that you can actually measure the voltages and amperages coming off the panels?

      Does your inverter say 3500W? That is VERY large for a 12V inverter, and again as SunEagle states, the inverter itself consumes power even when it's just sitting there powering nothing.

      I would take a guess and say your problem is a combination of random low-budgetcomponents thrown together in a less than optimal wiring scheme, and loads bigger than what the system can handle got placed upon it.

      In the mean time, here's what you can do. Pull the two batteries out, bring them home, and get them on an automotive 12V charger as quick as you can. If you can find a 20A charger, that would be best. They might already be damaged, but you might get lucky.

      Then, go on Ebay or Amazon, and order a multimeter asap. You can find something acceptable for 12$ or so. Then, start following the flow of electricity starting at your panels, measuring the voltage at each and every connection point. The numbers will give you a clue as to what is going on.
      Good luck!

      Comment


      • #4
        I think you’re going to find a way forward here.

        For the energy audit, there’s things you do like look up devices and enter them in spreadsheets to get an idea of what it is. I planned for 250 watts for a recharge laptop, and it turned out it was only 125 watts, but it was on icy longer than I thought it would be.

        Best way I’ve found is to hook a battery monitor up. I use a Victron BMV-712, but there’s plenty of shunts and monitoring systems out there. Other options include a kilawatt meter, but those just measure AC. In my case, most of my usage is on the DC side to run the propane heater’s fan. That is hard to measure without a battery monitor. I was also surprised about the difference between a night at 32 and a night at 50. Might have been a 60 AH difference, or about 720 wh.

        Two panels on the roofs of different sizes might not be a good idea. That’s why getting the specs off are important. If the panels put out the same amps, they can be put in parallel with no issues to max power out. That’s harder to do than it sounds.

        I think once this is over, you’ll be glad you cut ties with the guy that designed it. The thing that scares me is the inverter behind the toilet with what appears to be two live cables exposed.

        Comment


        • #5
          First off WOW I am blown away by the help I have already received in so little time, thanks to each and every one of you so far. Let me take all this as best I can, however before I go through everything you guys have suggested and reply to that, let me first say I am a former Network Administrator/Engineer and I own like 5 OHM Meters (Or Multimeters). It went with the territory of my former profession. That being said I helped wire this system but I am not, repeat not an expert on SOlar. My forte has always been in DC wiring, but after this summer I got a crash course in AC wiring as well. With that out of the way let me try to explain a bit more on whats going on.

          Suneagle is right, there is a major issue somewhere. As for exactly how my system is setup I am not 100% sure. I can tell you that the "Big" panel is 325 watts, and the small one is 100 watts. They are both tied together with a pigtail? (a special solar connection I cannot remember the name for those) that is waterproof and they continue after the tie in down to the controller. I am aware also the white thing is the controller as I helped wire it, although I do not entirely understand its workings. I have never measured the panels as my "solar" guy who set me up said everything was matched properly.

          Yes, that is a 3500 Watt inverter, 7000 watt peak. The reason for the size is the Microwave (yes the Microwave!) I imagine. Everything else is pretty low wattage. As for pulling the batteries off and taking them "home", this is my home (the TIny home) and I am in Mexico and the Tiny Home is under a tarp in my friends yard in Nebraska riding out the winter. As said before I do plan on taking the batteries to Interstate when i get back as they are under warranty for a year. They never charged properly to begin with, and I am not saying that is the batteries fault. I have a shunt installed in the wall, you can see it directly under the inverter, it runs to a battery monitor (Although I do not think he wired that correctly either since the Watt hour keeps rising the longer its connected).



          I do not plan on going back there again to the guy who designed it. I want to press forward from here. I am curious where you see the "live cables" are you referring to the ones that go to the fuse under the inverter, the big black and red ones? those are coming directly from the batteries in the front of the tongue outside.

          A quick list (by no means an extensive audit) of what is powering inside the tiny home

          12 VOLT System (powered by the DC side of the power converter center (big black box with breakers, but the shield is closed so they cannot be seen)

          4 recessed can lights over the sink on a throw switch (best guess .5 amps draw)
          8 LED strips under the tiny home that light up the underneath at dump stations, station lights) probably .2 amps total
          the solar emergency lights around the tiny home have their own panels, so those dont count I guess
          honestly thats probably it for the 12 volt side

          110 Volt system (powered by same converter box with two twin breakers for the master and 4 auxillary breakers)

          1 microwave, small but unknown draw, although the power meter has read 6.0 amp while it was under load before)
          7 AC outlets with onboard 5volt USB power, obviously they are not fully loaded down all at once.
          one midia fridge/freezer combo, the tag on the fridge says it draws 1.0 amps when under load, ive never seen the power meter rise above that.
          I have one laptop and one tablet that sometimes charge on the Ac/Dc outlets
          the heater is all propane with no electrical components
          the stove in the kitchen is propane fed, but it has an electrical ignition, I imagine that takes very little juice.
          cabinet lights over the stove (best guess .3 amps)
          I have a 32 inch tv installed in the bedroom, but I do not know the draw, I know its not very much.
          The control wall has a NAS (network attached storage system) with two hard drives in it, I do not know the draw for that.
          The modem/switch on the wall is also AC powered
          Two AC lights one in the kitchen one in the bedroom area.
          I have an Air conditioner (6k btu?) when at FULL cool it draws between 5-6 amps
          I have my Ryobi drill charger i plug the batteries in sometimes, not sure its exact load.
          sometimes the cell phone is plugged in and the wireless weather station on the roof has a monitor that is powered by AC but its probably using .1 amps at the most

          I realize this is a lot, and I am sorry I cannot give exact information, but you have my word when I tear this thing down in Utah for a refit, Ill go over ALL of this with a fine tooth comb. I am glad you guys are here to help.

          BTW I didnt have a choice on my solar guy, everyone I called said they didnt do small projects and were only into house and large installs, and everyone of them recommended this guy, and he was literally the only option for 100s of miles.

          I know I screwed up, but my goal now is to fix it. All I wanted was an off grid system that I could power my tiny home with.

          I have included a couple photos, and while I know it wont answer your questions, I hope it helps a little! (If on computer you can hover over the photos for the descriptions)

          Again I appreciate all the help, I really do!

          20200825_175137.jpg

          IMG_0061.JPG

          IMG_0101.JPG

          IMG_1122.JPG

          IMG_1145.JPG

          Comment


          • #6
            I see a few issues with your system.

            The first is two unequal panel wattage that may fight each other. Most solar pv systems use all the same type of panels with Vmp and Imp being within 5% of each other. A 100watt and 325watt panel are just way too different to be connected together.

            Second I think your loads are way too big for a 12v 220Ah system. Both the micro wave and AC unit will suck down the battery system quickly and you do not have enough panel wattage to replace the amp-hours used.

            An FLA battery can be safely drained maybe 30% each day. More will cut the number of cycles it can deliver in it's life. That calculates to (12v x 220Ah x .30 = 792watt hours). And that is only good if your panels can generate 125% of what you took out of the batteries. Unless the panels are pointed at the sun for at least 4 hours a day you will never generate 990 watt hours a day.

            Third is that 3500watt inverter is big and can drain your batteries just being turned on without loads. Even with a 5% no load rating you are talking about over 150watt load for every hour it is on.

            You are correct. You were screwed with this system. You will need a lot more panel wattage as well as battery system to run your loads. The biggest issue with off grid systems is that unless you have performed a good watt hour usage plan the batteries will quickly die leaving you in the dark.

            Comment


            • #7
              Originally posted by SunEagle View Post
              I see a few issues with your system.

              The first is two unequal panel wattage that may fight each other. Most solar pv systems use all the same type of panels with Vmp and Imp being within 5% of each other. A 100watt and 325watt panel are just way too different to be connected together.
              So having that "helper panel" up there is doing more harm then good!

              Originally posted by SunEagle View Post

              Second I think your loads are way too big for a 12v 220Ah system. Both the micro wave and AC unit will suck down the battery system quickly and you do not have enough panel wattage to replace the amp-hours used.
              I did forget to mention I do have a generator, so the AC is RARELY run without a generator fed into the power converter, I have run it on the solar, but only for a couple minutes, just to see the load.

              Originally posted by SunEagle View Post

              An FLA battery can be safely drained maybe 30% each day. More will cut the number of cycles it can deliver in it's life. That calculates to (12v x 220Ah x .30 = 792watt hours). And that is only good if your panels can generate 125% of what you took out of the batteries. Unless the panels are pointed at the sun for at least 4 hours a day you will never generate 990 watt hours a day.
              I mean theoretically its "possible" to get sun that long per day, but obviously its not working now

              Originally posted by SunEagle View Post
              Third is that 3500watt inverter is big and can drain your batteries just being turned on without loads. Even with a 5% no load rating you are talking about over 150watt load for every hour it is on.
              SO I guess the ultimate question is what now? Where do I even begin, is that inverter worth anything to anyone, or am I throwing good money after bad with new stuff?

              Originally posted by SunEagle View Post

              You are correct. You were screwed with this system. You will need a lot more panel wattage as well as battery system to run your loads. The biggest issue with off grid systems is that unless you have performed a good watt hour usage plan the batteries will quickly die leaving you in the dark.
              I suspected as much, full disclosure I only paid him 1500 for the system, 1000 cash upfront, and then 500 for the install, I still "owed" him a thousand more for the rest, but I never felt right paying him the remainder as I had so many problems. I even went back to have him fix the issues, and he blew up the inverter by swapping a wrong wire, and I had to wait a a few days for the new one to come in again. Photo shows where he blew the capacitor on the surge side, and me swapping the inverter out.

              IMG_0562.JPGIMG_0563.JPGIMG_1118.JPG

              Well Im in the hands of you awesome people, you tell me what to do and ill start on it as soon as I can, if this is something I CAN do alone, and its patching up a screwup, Ill do so, if I need to get this into the hands of an actual professional, Ill do that as well, though I do not know where to start. Finally I want to point out there is almost no room for more then ONE full size panel up on that roof, there is a lot of stuff up there. I am sure it is possible to make something work, I just do not know what yet

              Again I thank you all for the help, and look forward to any information I can glean from all this!

              Comment


              • #8
                This site has some great stickies on batteries. You may need to equalize the batteries to recover them. At least that’s what my Trojan battery bank says to do if it’s weak when fully charged.

                I really think for now to start looking at systems that people have built. That way you’ll see what’s right for you.

                This is my build that I go into some detail about

                https://diysolarforum.com/threads/my...-panels.14212/

                Something like that will be perfect for your small home, but won’t power AC. That’s a whole other issue. Basically on a 12 volt system you’ll need 70 dc amps to make 5 or 6 AC amps. Basically more than your panels can realistically produce, even the amount I have. This video goes into detail.

                https://m.youtube.com/watch?v=zawAaI-HS9U

                Comment


                • #9
                  OK, the guy you hired is an idiot that doesn't know what he is doing. What I would do at this point is gut everything out and start over from scratch. Whether or not you keep this equipment will be dependent on how you want to proceed. It might be better to just demand a full refund and start over.

                  First, the batteries. Those do NOT look like 210Ah 6V batteries! A 6V battery of about 210Ah should be about 60-70lb, and only about 12" tall. Those look more like 6V 400Ah batteries? That would be part of the problem right there. Bigger batteries need more solar to charge. Could he have meant 210Ah available? That would be 50% capacity.

                  There are two basic charge controller types, PMW, and MPPT. PMW acts as a simple on/0ff switch, directing charge current to the battery. The battery voltage decides the voltage your panel will output at. You appear to have a MPPT controller. It takes higher voltage and transforms it down to what the battery wants. If you connect a 30V grid-tie panel putting out 8A, it will transform the voltage down to ~13V and charge the battery with around 16-18A.

                  For MPPT to work, you need voltage significantly higher than 14-15V for charging a 12V battery. So, connecting a 12V 100W panel along side a 30V panel is just ignorant. Did he wire them in parallel or in series?

                  Assuming your batteries are in fact 400Ah, then the amount of watts you need is 400Ah X 0.1charge rate X 13V X 1.25fudgefactor = 650W, or two of your "big panels". You can wire the two panels in series to get 60-72V, and feed that high voltage DC into your controller. Then your controller will transform the high voltage down to ~13V or so for the battery, but at increased amperage. You will need to check what the amperage limit of your controller is, because on paper that would be ~50A. If laying flat on the roof though, it would ever get even close to 50 except at noon.

                  It sounds like you could do it, you just need some coaching in terms of equipment selection and wiring advice.

                  Comment


                  • #10
                    Originally posted by MichaelK! View Post
                    OK, the guy you hired is an idiot that doesn't know what he is doing. What I would do at this point is gut everything out and start over from scratch. Whether or not you keep this equipment will be dependent on how you want to proceed. It might be better to just demand a full refund and start over.
                    Michael, first off, I agree with you in principle, but I am not one to call names. In the past I was seriously bad at trolling and starting fights in forums, so I understand your hostility towards a bad setup. I will say a full refund (and consequently me paying him the difference of what he was "owed") is highly unlikely.

                    Originally posted by MichaelK! View Post
                    First, the batteries. Those do NOT look like 210Ah 6V batteries! A 6V battery of about 210Ah should be about 60-70lb, and only about 12" tall. Those look more like 6V 400Ah batteries? That would be part of the problem right there. Bigger batteries need more solar to charge. Could he have meant 210Ah available? That would be 50% capacity..

                    Obviously being in Sunny Mexico I cannot give you all the information, I can TRY to lookup the copies of the invoices, which Ill happily provide here, but short of really taking better photos of the batteries, which I can do when I return to the states, were just guessing. ALthough, in your defense you have a better idea of this stuff already. I was told they were "deep cycle 6 volt, @ 220 AH, again only what I was told.

                    Originally posted by MichaelK! View Post
                    There are two basic charge controller types, PMW, and MPPT. PMW acts as a simple on/0ff switch, directing charge current to the battery. The battery voltage decides the voltage your panel will output at. You appear to have a MPPT controller. It takes higher voltage and transforms it down to what the battery wants. If you connect a 30V grid-tie panel putting out 8A, it will transform the voltage down to ~13V and charge the battery with around 16-18A.
                    While the charge controller remained a mystery to me, I do understand what your saying. I will say that when we first tested the system direct from the first large panels sun output, we saw 36 volts come across the charge controller. The only information I was ever able to find on that charge controller was some video in a weird "THAI" maybe dialect, anyway it was indecipherable even though it was clearly showing how to operate the device.

                    Originally posted by MichaelK! View Post
                    For MPPT to work, you need voltage significantly higher than 14-15V for charging a 12V battery. So, connecting a 12V 100W panel along side a 30V panel is just ignorant. Did he wire them in parallel or in series?
                    As for the second panel, I was unhappy with the system and hoping to give it a boost. I did not have prior knowledge to solar, and I know I should have, but there were a thousand things going on with this build. As for your other question concerning the tie in, the first panel and second panel go to a special adapter then ONE line runs to the charge controller, so in "series"?.

                    Originally posted by MichaelK! View Post
                    Assuming your batteries are in fact 400Ah, then the amount of watts you need is 400Ah X 0.1charge rate X 13V X 1.25fudgefactor = 650W, or two of your "big panels". You can wire the two panels in series to get 60-72V, and feed that high voltage DC into your controller. Then your controller will transform the high voltage down to ~13V or so for the battery, but at increased amperage. You will need to check what the amperage limit of your controller is, because on paper that would be ~50A. If laying flat on the roof though, it would ever get even close to 50 except at noon.

                    It sounds like you could do it, you just need some coaching in terms of equipment selection and wiring advice.
                    I will be glad to give you all the information, and I fully intend on doing a new setup, using some of the old parts if possible, but I am going to decommission the smaller panel. I may be able to use it for something else, who knows.

                    I also totally agree I can wire a new system with the help of you awesome people, and fully intend on doing a complete retrofit this summer, including the solar.

                    Thanks to you and to everyone for the awesome support. My only issue is there is just no physical room for another large panel, but I am working on a crazy idea to make that possible. Once I have a crappy sketch I will post it here for feedback.

                    Thanks Again Everyone

                    Comment


                    • #11
                      MichaelK!

                      Confirmed the batteries are

                      Interstate L-16 400AH 6 volt

                      the controller is an PowMr 60 Amp???

                      Ill post the invoices soon everyone!

                      Comment


                      • #12
                        Invoices Attached, Hope this helps!

                        Attached Files

                        Comment


                        • #13
                          You can't mix PV panels at random, they need to be matched
                          Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
                          || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
                          || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

                          solar: http://tinyurl.com/LMR-Solar
                          gen: http://tinyurl.com/LMR-Lister

                          Comment


                          • #14
                            As for your other question concerning the tie in, the first panel and second panel go to a special adapter then ONE line runs to the charge controller, so in "series"?.

                            Did the solar connectors you referred to above look like the letter Y?

                            If the answer is yes, then you do NOT have a series connection, but a parallel one. I'm not trying to be an ass, but you absolutely need to understand solar terminology if you are going to put together a functioning system.

                            You first need to understand the addage, in series volts add, but amps stays the same. In parallel, amps add, but voltage stays the same. So, it looks like what the installer did was place a 37V panel in parallel with a 12V panel. I will not use the i-word again, but I have to say you are NOT getting value for your installation dollars.

                            I think your best bet is to totally disassemble the system, and re-wire it from scratch. The low amp output is going to be a serious problem for your 400Ah batteries. What you will need to do is go up on the roof and figure out how many panels of whatever size will fit, either your big grid-ties or little 100W 12V panels. Then wire them in series to get 60-75VDC. A series connection is connecting the +connection of panel #1 to the -connection of panel #2, then the +connection of panel 2 goes to the -connection of panel three, and so on and so on. Keep in mind that laying flat you are not likely to see more than 60% output, so your panels needed would be (400Ah X 1/10C X 13V charging X 1.25FF)/0.6 = 867W. Call i 800 or 900W of panels

                            You will need to increase the number of amps charging those batteries, or decrease the size of the batteries. There's no such thing as a free lunch. It's going to work when it's done properly.

                            Comment


                            • #15
                              Originally posted by MichaelK! View Post
                              As for your other question concerning the tie in, the first panel and second panel go to a special adapter then ONE line runs to the charge controller, so in "series"?.

                              Did the solar connectors you referred to above look like the letter Y?

                              If the answer is yes, then you do NOT have a series connection, but a parallel one. I'm not trying to be an ass, but you absolutely need to understand solar terminology if you are going to put together a functioning system.

                              You first need to understand the addage, in series volts add, but amps stays the same. In parallel, amps add, but voltage stays the same. So, it looks like what the installer did was place a 37V panel in parallel with a 12V panel. I will not use the i-word again, but I have to say you are NOT getting value for your installation dollars.

                              I think your best bet is to totally disassemble the system, and re-wire it from scratch. The low amp output is going to be a serious problem for your 400Ah batteries. What you will need to do is go up on the roof and figure out how many panels of whatever size will fit, either your big grid-ties or little 100W 12V panels. Then wire them in series to get 60-75VDC. A series connection is connecting the +connection of panel #1 to the -connection of panel #2, then the +connection of panel 2 goes to the -connection of panel three, and so on and so on. Keep in mind that laying flat you are not likely to see more than 60% output, so your panels needed would be (400Ah X 1/10C X 13V charging X 1.25FF)/0.6 = 867W. Call i 800 or 900W of panels

                              You will need to increase the number of amps charging those batteries, or decrease the size of the batteries. There's no such thing as a free lunch. It's going to work when it's done properly.
                              Michael,

                              I already told you I have no knowledge of this stuff. When I built the TINY I learned a lot, but paid someone else to do the solar. I am fully capable and eager to learn all there is to know to make this right. I totally agree I did not get the value out of the install, but what is done is done.

                              as for the panels in series or parellel, well I took a guess. I remember the "Y" connector having "I word proof connections" as I was told. You simply could not hook them up wrong. I agree that starting from scratch will be best. My first thought is a smaller "inverter" and I am not sure if I will keep the batteries. I guess that depends on how much panel space I can manufacture and also more importantly my "energy audit" count once it is done.

                              I cannot stress enough I appreciate every word written here, I have had more help and more advice and more everything then I ever got from my installer.

                              Finally as I do like to learn, any easy to understand resources you wish to share to get me to "bone up" on this, I would be happy to digest. Preferably from a trusted source and not someone on Youtube looking for more clicks on their channel.

                              Thanks

                              BTW, this is what is on the roof running from the panels to the Charge controller!

                              2021-02-10_23-37-43.jpg

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