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Newbie, Van life 500 Watt Solar setup

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  • Newbie, Van life 500 Watt Solar setup

    Hey guys! I just started learning about solar and I've purchased everything I need for my new setup.This is for a Van conversion of a 170" sprinter.

    What I have:

    5x 100 12V solar Panels from Renogy

    40 amp MPPT (Max input 520 watts)

    100 Watt Pure Sine inverter

    5x 155ah AGM batteries

    My questions:
    What gauge wire do I need to connect...
    MPPT> Batteries
    MPPT> Breaker Box
    Batteries> Batteries
    Batteries> Inverter

    I also have a bunch of different fuses and fuse sizes I don't know where to place.

    Any insight would be Awesome!!! Thanks!
    Last edited by Dirtydeeds; 04-12-2019, 09:15 PM.

  • #2
    Quick pic of my setup so far ( Wires are just place holders )
    Attached Files

    Comment


    • #3
      Batteries like to have a C/12 to C/8 charge rate, which in your case would be 65-95 amps. Panels on rooftops typically produce around 80% of nameplate power, and you'll get less than that if your panels are mounted horizontally, I'd guess around 60%. So with 500 watts you might get around 25 amps, which is far too little for the batteries you have if you plan to use them all. Also wiring them in parallel combined with chronic undercharging will destroy them in short order. Could you get by with only two of those batteries? It depends on your daily needs in watt hours. Have you determined your daily loads?

      By the way five panels forces you to wire all in series, or all in parallel. All in parallel requires fuses, combining and larger wire, series does not, so it's a better option, but you need to be certain the open circuit voltages of the panels x5 doesn't exceed the max voltage input to the controller, especially in cold weather where the panel voltage might exceed Voc on the label.
      Last edited by sdold; 04-12-2019, 09:42 PM.

      Comment


      • #4
        Originally posted by sdold View Post
        Batteries like to have a C/12 to C/8 charge rate, which in your case would be 65-95 amps. Panels on rooftops typically produce around 80% of nameplate power, and you'll get less than that if your panels are mounted horizontally, I'd guess around 60%. So with 500 watts you might get around 25 amps, which is far too little for the batteries you have if you plan to use them all. Also wiring them in parallel combined with chronic undercharging will destroy them in short order. Could you get by with only two of those batteries? It depends on your daily needs in watt hours. Have you determined your daily loads?
        Thanks for your Reply! I'm also planning on using a Smart Battery Isolator and I'm going to be on the road full-time. Do you think that the smart Inverter + Solar panels will top off my batteries? For my electricity needs, I need at least 3,000 watts Daily. with the 4 batteries wired in parallel, they'd be able to hold something like 7440 Watts (or watt hours, no sure of the right terminology here), and If I'm not mistaken, to take care of the batteries you're supposed to only use up to 50% of their juice (which in my case would be 3,000 watts)

        Comment


        • #5
          For the layout and fuse/circuit breaker location study this diagram from AltEStore. Link to higher resolution (original) diagram here.
          off_grid_solar_system_schemati





          For more detailed info on that, from the same site watch her [B]video [/B]:
          Solar Electric Components - Part 4 - Overcurrent Protection (OCP)

          Comment


          • #6
            Remove the loads from the load output of the CC. The load output on the CC is only for a small load, (lighting circuit), which can be activated by darkness and run for a pre selected amount of time. Connect the fuse block, as well as the inverter, directly to the battery.

            Your first sentence explains a lot. You should have learned a lot more about solar charging and systems before you spent any money on equipment. You spent way too much on solar panels than you should have. You are going to ruin your batteries in short order with all the parallel connections. Once you figured out your load requirement you should have bought the proper size batteries to have a single string, at most 2 strings, if the right size batteries aren't available to you. As sdold already mentioned, 5 panels severely limit your wiring choices. Actually you don't have ANY choice with all 5 panels being that all in parallel will give you too low of voltage for your MPPT controller to work properly and all 5 in series will give you too high of voltage. You need to scrap one panel and wire in 2s2p configuration or scrap 2 and wire in 3s configuration.. You could have saved yourself over $300.00 and bought a couple 250 - 300 watt panels. That would have bought a lot of beer or fuel for your travels.

            PS, don't drink and drive
            Last edited by littleharbor; 04-13-2019, 07:52 AM.
            2.2kw Suntech mono, Classic 200, NEW Trace SW4024

            Comment


            • #7
              Originally posted by littleharbor View Post
              Remove the loads from the load output of the CC. The load output on the CC is only for a small load, (lighting circuit), which can be activated by darkness and run for a pre selected amount of time. Connect the fuse block, as well as the inverter, directly to the battery.

              Your first sentence explains a lot. You should have learned a lot more about solar charging and systems before you spent any money on equipment. You spent way too much on solar panels than you should have. You are going to ruin your batteries in short order with all the parallel connections. Once you figured out your load requirement you should have bought the proper size batteries to have a single string, at most 2 strings, if the right size batteries aren't available to you. As sdold already mentioned, 5 panels severely limit your wiring choices. Actually you don't have ANY choice with all 5 panels being that all in parallel will give you too low of voltage for your MPPT controller to work properly and all 5 in series will give you too high of voltage. You need to scrap one panel and wire in 2s2p configuration or scrap 2 and wire in 3s configuration.. You could have saved yourself over $300.00 and bought a couple 250 - 300 watt panels. That would have bought a lot of beer or fuel for your travels.

              PS, don't drink and drive
              Okay awesome! I can Return 1 Panel that's no problem. So with a 2s2p configuration, would the all the panels be affected if one of them were to be under shade? also, wouldn't that turn the whole system into a 24V system? thanks!

              Comment


              • #8
                Originally posted by Kbarb View Post
                For the layout and fuse/circuit breaker location study this diagram from AltEStore. Link to higher resolution (original) diagram here.
                off_grid_solar_system_schemati





                For more detailed info on that, from the same site watch her [B]video [/B]:
                Solar Electric Components - Part 4 - Overcurrent Protection (OCP)
                Thank you! video explains a lot!

                Comment


                • #9
                  2s2p, If one panel shaded it will affect the output of one of the strings.
                  MPPT controllers will step down the higher input voltage to the battery voltage, that's what they do. You do need to connect the battery first so that the controller will recognize the system as being 12 volts.

                  Another problem you have is the size of your battery bank . You have a 775 amp hour battery bank which would require 75 amps of charging power to use on a daily basis. Do you really need that much battery? Do some serious analyzing of what you really need or, get ready to buy a new 80 amp charge controller and about 4 of those 300 watt panels I mentioned.
                  Last edited by littleharbor; 04-13-2019, 10:11 AM.
                  2.2kw Suntech mono, Classic 200, NEW Trace SW4024

                  Comment


                  • #10
                    Originally posted by littleharbor View Post
                    2s2p, If one panel shaded it will affect the output of one of the strings.
                    MPPT controllers will step down the higher input voltage to the battery voltage, that's what they do. You do need to connect the battery first so that the controller will recognize the system as being 12 volts.

                    Another problem you have is the size of your battery bank . You have a 775 amp hour battery bank which would require 75 amps of charging power to use on a daily basis. Do you really need that much battery? Do some serious analyzing of what you really need or, get ready to buy a new 80 amp charge controller and about 4 of those 300 watt panels I mentioned.
                    I can possibly get by on 3 155ah batteries. It complicates things a little to buy a 300 watt panel because I have 2 fans installed on the roof of my sprinter. I only have space for 100 watt panels.How many amps would I pull in with 2s2p?

                    Comment


                    • #11
                      The way I see it with flat mounted panels on a hot roof you'd be lucky to see 300 watts /13 volts = 23 amps,at best. The majority of the time you'll see less.
                      2.2kw Suntech mono, Classic 200, NEW Trace SW4024

                      Comment

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