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  • Seeking solar panel advice for "backup" battery

    Hello all,

    I would like to get some advice on a setup to charge a deep cycle battery that I will be using as a backup when the power goes out. I have already purchased the Trojan 27 TMX 12v deep cycle battery and the Optimate 6 battery charger. I will use the Optimate to keep the battery in good health while the grid is up and once setup the way I want it I plan to use the Trojan on occasion just to practice the off-grid scenario.

    At this point the only thing I wish to power with the Trojan is my 12v amateur radio. The radio consumes 10.8w (0.9a @ 12v) in receive mode and 240w (20a @ 12v) when transmitting at full (100w) power. I have a volt meter connected to the setup so I can monitor the health of my Trojan in that way (I also have a good hydrometer). Typical use of the radio during a power outage would be 2-3 hours of receive (3 hours * 10.8w = 32.4w) and perhaps 15-30 (1/2 hour * 240w = 120w) minutes of transmit per day so that would be about 150w/day or thereabouts.

    So, what I am looking for is a single solar panel setup, MPPT charge controller, and wire recommendations. In the future I may want to add another panel so I would like the charge controller to handle two panels. I want to overbuild in case I go bigger. Off the top of my head I may want to connect my SkyRC MC3000 battery charger in order to charge up some Eneloops for the flashlights, not at the same time as I use the radio. Let's say two 1500mAh AAs a day is 1.5v @3amp is ~5watts is that correct? So not much more use.

    The solar panel will be about 100' from the charge controller which will be near the battery, the battery being near the radio in a well-ventilated area. So, for the wire recommendation it will need to account for the 100' run.

    Don't need Bluetooth or anything like that on the MMPT however good indicator lights on the MPPT would be nice so I can tell at a glance what's going on or some other means per your recommendations.

    My location is zip code 92075 San Diego County, California.

    In a nutshell:
    Trojan TMX 12v deep cycle battery
    Approx. 150 watts daily use
    Need recommendation for a single panel, MPPT charge controller, and 100' run of wire (what gauge wire? what connectors to use?)

    Thank you!
    Michael
    Newbie

  • #2
    I'll assume you know about fuses, and their function to protect the wires from accidental shorts and prevent a fire from starting. every + wire from the battery, needs a fuse on it to protect the wire. That would be the Radio wire and the Charge controller wire, and the wire to the accessory chargers. Fuse should be able to carry the expected load, and the wire needs to be large enough to not cause voltage loss.

    Panel: Any cheap Grid Tie panel, from 150w - 300w. You go to the solar store, see what's on the shelf, or on sale, and carry it home. Voltage should be at least 28Vmp, no more than 50Voc
    You will spend as much buying a 100w 12v panel (made by the 100's) as a GT panel, (made by the millions)
    Mount it on a sandwich board or sawhorse, weight it with sandbag so it does not blow over. Any shade on a panel will greatly reduce it's power output. Shadow from a twig, pencil, or piece of tape is bad.

    Charge controller. I really like the sunsaver https://www.morningstarcorp.com/products/sunsaver-mppt/
    It's solid.

    I like Anderson Connectors.

    The long run will only carry 10A or so, a cheap, repurposed 12ga extension cord would be fine. replace the ends with Anderson connectors, get a 6' MC4 extension cord, cut it half. and use that to make the connection to the PV and the cut ends, get an Anderson connector.
    Controller to the battery should be shorter, and at least 10ga wire.

    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


    • #3
      Thanks for the solid advice Mike! I'll let you know what I pick up. And thanks for the reminder on the fuses. I'm using a West Mountain Radio RIGrunner distribution panel from my 12v power supply to my radio and other 12v devices so those fuses are covered however I see the need for fuses for the charge controller. Yes I am using Anderson Power Poles everywhere and 12ga wire. I'll make sure I use 10ga for the connection from the charge controller to the battery. For fuses what do you recommend? Inline glass fuses or the newer spade type?

      Thanks again!
      Michael

      Comment


      • #4
        I actually prefer circuit breakers. Midnight solar has DC breakers that carry switch duty rating.
        But for fuses, I like panel mount glass AG style fuses. Make sure they carry a DC break rating.

        The mini automotive spade fuses are no good, the spring contacts are weak. The Maxi fuses have better contacts for their spade fingers.

        I'm also partial to the Battery terminal fuses
        https://www.bluesea.com/products/215...k_-_30_to_300A
        that bolt right onto the battery. For simple solar setups, I use a 30A fuse for the controller wire, and a 200A for the inverter. In your case, I'd use a 50A fuse for the #6 cable to your distribution buss. (or the right fuse for the wire size you run)
        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


        • #5
          Was thinking about this panel. Its a Mission 365w model MSE365SQ9S that is available locally.

          http://www.solardesigntool.com/compo...ata-sheet.html


          Thoughts?
          Michael
          Last edited by mjgillen; 07-10-2019, 04:24 PM. Reason: added link

          Comment


          • #6
            panels you don't have to pay shipping on, save a lot of $$. I have not followed the panel marked much, don't know much about Mission
            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


            • #7
              Well I congratulate you on using the Optimate 6 as a general purpose charger for your offline storage. I've covered it a few times here.

              Tip: if your buddies are running "pure lead" agm's, like Optimas or Odysseys, and they want just to be a tad bit more perfectionist about it, the later model Optimate 7 has a higher-voltage setting (14.7v) that the pure-leads like to see. For *conventional* agm's, and floodies, the '6 is just fine. Hard to go wrong with either unless you really get into it.

              nimh charging - simple. Just use a *quality* individual-cell charger like the venerable Maha/Powerex C9000. Or other Maha/Powerex units with dc-input capability. The can be quickly whipped together with nothing more than the usual cigarette-adapter jack that connects straight to the battery. Don't fool around with the "LOAD" terminals on a controller. Straight to the batt. There is a lot of nimh charger trash out there. Do it right the first time, especially since we're talking about emergency uses, not just casual hobbiest stuff.

              Panel tips:
              Looks like that panel is a 38v vmp panel, which may need to incorporate a controller with a higher voltage capability. Personally, I'd start with the venerable "12v nominal" panel (which actually means approx 18v unregulated vmp) and a lower cost controller like Mike has pointed out. And, in the field, if yours breaks, it is more likely a fellow amateur will also have a "nominal 12v" panel on hand - not the higher voltage ones.

              Morningstar controller tips - choose the jumper setting more appropriate to your battery chemistry and not just the "label". For instance, far too many using sealed agm batteries will use the jumpers for "sealed". When in fact they should be using the jumper setting for flooded, which is slightly higher in voltage. Some of the "quickie" setups, without looking at the what the voltage in the manual for what the outer labels *really mean* can lead to under or overcharge.

              For instance, with my conventional agm's, I remove the jumper for *flooded* labels - only because 14.4v is what I really want with the agm. Morningstar's "sealed" voltage is 14.1, which is fine for GEL (which I don't recommend), but undercharges agm's. I know you aren't using an agm, but is good info for the field.

              More field tips:
              Panels want to be *fully exposed* with NO shading across them. That means even small shadows like overhead cabling, yagi arm element shadows and so forth. Also be sure to ELEVATE your panel if just plopping it down in the grass. Even small grass-shadows near the panel can reduce their output greatly. I see this a LOT. Just a few inches can make a big difference. Evaluate your shadowing during the day as shadows change or elongate.


              Comment


              • #8
                MPPT vs PWM controllers:

                Might as well bring up this perennial subject.

                If you are already using less than 200 watts of panel power, the actual gains you see with mppt might not matter in the *real world*. It may be more effective and less costly to just use more panel to begin with. Once you get beyond 200 watts, then perhaps think about it.

                BENCH RACING NERD WARS and the real world:

                Yes, on paper, mppt does a better job. But, the el-cheapo controller manufacturers know that MPPT is a very tempting buzzword and have in the past actually marketed simpler pwm controllers as mppt. OR, if they do use mppt, their actual algorithm for it outright sucks.

                What this means is that like anything, you get what you pay for. A true, reliable MPPT controller is going to cost you. A cheap no-name might fail in a week, despite the glitzy specs. And when all is said and done, at the end of the day, will an mppt on a <200w panel system gain you an extra EIGHT minutes of load capacity?

                What I'm saying is that I'd prefer a QUALITY pwm controller from a reputable manufacturer any day over a cheap mppt that might not bring me any real-world benefits when less than 200 watts system output and the cheap mppt smokes just when you need it.

                Comment


                • #9
                  Well, I was thinking about getting the Morningstar SS-20L-12V Sunsaver MPPT charge controller however looking at the specs it appears that it is limited on how much voltage it can handle.

                  https://www.bluepacificsolar.com/pic...ion-manual.pdf

                  If I read that correctly it cannot handle anything above 25Voc so a few questions:

                  1. Is this MPPT CC going to fulfill my needs for one (currently) deep cycle battery and would that CC also handle an additional battery in parallel (so still 12v).
                  2. If this is not a good MPPT CC choice for my needs can you recommend something?
                  3. Can you also recommend a panel that pairs well with the recommended MTTP CC?

                  Just when I thought I might know something there I go showing that I don't know much. Although I did get the Optimate 6 which is one heck of a battery charger!

                  Thanks,
                  Michael
                  Last edited by mjgillen; 07-10-2019, 09:27 PM. Reason: added link

                  Comment


                  • #10
                    The MPPT version is here https://www.morningstarcorp.com/products/sunsaver-mppt/
                    and has a 60V max input voltage regardless of battery voltage.

                    Your link was to the sunsaver PWM controller, which is only allowed a couple volts above max battery voltage. Another sign of a low quality vendor, pushing the wrong parts.
                    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


                    • #11
                      Thank you Mike90250 I feel better about picking up that big panel. I think that will work for now. Here is what I'm planning for now comments and advice welcome:

                      Panel: Mission 365w model MSE365SQ9S made in USA http://www.solardesigntool.com/compo...ata-sheet.html
                      MPPT Controller: Morningstar Sunsaver SS-20L-12V https://www.morningstarcorp.com/products/sunsaver-mppt/

                      Michael

                      Comment


                      • #12
                        So the Morningstar Mission Solar SS-20L-12V MPPT charge controller with the MISSION MSE365SQ9S (365W) Solar Panel is my current bill of materials. Any comments on this?

                        Michael

                        Comment


                        • #13
                          Originally posted by mjgillen View Post
                          Thank you Mike90250 I feel better about picking up that big panel. I think that will work for now. Here is what I'm planning for now comments and advice welcome:

                          Panel: Mission 365w model MSE365SQ9S made in USA
                          MPPT Controller: Morningstar Sunsaver SS-20L-12V https://www.morningstarcorp.com/products/sunsaver-mppt/

                          Michael
                          As long as you are sure you are getting the MPPT version of the controller. Morningstar has a odd way of reusing nearly the same model #'s for the PVM and MPPT lines.
                          You are giving the model # for the PWM version and linking to the MPPT version SS-MPPT-15L

                          With the 365W panel, you could easily see 26A from the controller. The SS-MPPT-15L should be able to manage that ok, but you won't get full power from the panel. Maybe
                          look at the Compare Page https://www.morningstarcorp.com/comp...82&product_03=
                          you can see the differences between the 15A and 25A models

                          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
                            Hi guys!

                            For the panel I got the Mission MSE375SQ9S 375w panel

                            https://www.ecodirect.com/Mission-So...mse375sq9s.htm

                            and the Morningstar ProStar PS-MPPT-25M charge controller

                            https://www.ecodirect.com/Morningsta...s-mppt-25m.htm

                            Reading the Morningstar manual preparing for installation it mentions a ground and GFCI. Right now I am using a copper pipe connected to an outside hose bib, will that be sufficient for a ground? I'm asking if I'm supposed to install an 8' ground rod. And do I need to add a GFCI?

                            The CC installation will be in an area under the house which is about 20'x20' however only about 4' in there for height so not sure if I can sink a ground rod may not have the height. I'm planning on running 10ga PV wire from the panel (on my flat roof) to the CC with a breaker close to the CC. Then CC to battery only a couple feet of same 10ga PV wire with another breaker in between. Then 10ga wire to my distribution panel for my radio. Will mount CC and breakers on a piece of plywood. Battery on a plywood pad as level as I can get it.

                            Thoughts?
                            Michael
                            Last edited by mjgillen; 07-18-2019, 10:47 AM. Reason: typo

                            Comment


                            • #15
                              OK guys got the install done except the ground and I am not sure if I need a GFCI any help appreciated on what to do for a ground. Like I mentioned, my radio equipment is grounded to a cold water pipe which is an outside the house hose bib. I don't want to ground to the same thing, am thinking I need to sink at least a 4' ground rod in the crawl space where the MPPT is. Thoughts opinions recommendations etc. appreciated. I'm ready to power it on and see it working!

                              Thanks,
                              Michael

                              Comment

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