Announcement

Collapse
No announcement yet.

Wiring a battery bank for Solar Panels OFF GRID

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Wiring a battery bank for Solar Panels OFF GRID

    Hi,
    I have a Solar panel bank connected via an MPPT controller connected to a battery bank.
    I have 10 12v 110ah batteries currently connected in parallel with the MPPT connected diagonally and the inverter connected the opposite diagonal.
    Can anyone tell me if this is the best way of connecting the battery bank or am i likely get bad circulation in the batteries themselves?
    Any advice would be appreciated, Thanks

  • #2
    Originally posted by Thomastheo1 View Post
    Hi,
    I have a Solar panel bank connected via an MPPT controller connected to a battery bank.
    I have 10 12v 110ah batteries currently connected in parallel with the MPPT connected diagonally and the inverter connected the opposite diagonal.
    Can anyone tell me if this is the best way of connecting the battery bank or am i likely get bad circulation in the batteries themselves?
    Any advice would be appreciated, Thanks
    Welcome to the forum Thomas. 10 batts in parallel is a big no no... also your controller and inverter should be connected on the same diagonal connection.
    read this,
    http://www.smartgauge.co.uk/batt_con.html

    Comment


    • #3
      " I have a Solar panel bank connected via an MPPT controller connected to a battery bank.
      I have 10 12v 110ah batteries "

      Just caught this... A solar panel?? 10 110Ah batteries? Sounds way off!

      edit: hahaha, thought I was awake... "a solar panel BANK" ok
      Last edited by FloridaSun; 01-06-2014, 09:37 AM. Reason: oops

      Comment


      • #4
        Thomas

        Maybe to avoid any further confusion you should provide us with the specifications of your equipment like: the number of solar panels including the wattage, Vmp & Imp rating. MPPT model and amp rating. Inverter type and watt rating.

        Also as FloridaSun points out, 10 parallel batteries will be an issue getting them to charge and discharge equally.

        A large battery system like yours (12 volt at 1100Ah) will require at least 1500 watts of solar panels or more depending on where you live.

        If you need that much battery going to a 48volt system using 8 batteries (2 strings of 4) would be better.
        Last edited by SunEagle; 01-06-2014, 11:16 AM. Reason: suggested 48volt battery system.

        Comment


        • #5
          Thanks for this Floridasun, your help has been fantastic.
          I have read the link and I will change it over today to method 3 or 4.
          The system has been running for about 1 1/2 years like this as it was our holiday home until recently (now here full time) do you think it would have done any damage?

          Comment


          • #6
            Originally posted by SunEagle View Post
            Thomas

            Maybe to avoid any further confusion you should provide us with the specifications of your equipment like: the number of solar panels including the wattage, Vmp & Imp rating. MPPT model and amp rating. Inverter type and watt rating.

            Also as FloridaSun points out, 10 parallel batteries will be an issue getting them to charge and discharge equally.

            A large battery system like yours (12 volt at 1100Ah) will require at least 1500 watts of solar panels or more depending on where you live.

            If you need that much battery going to a 48volt system using 8 batteries (2 strings of 4) would be better.
            Hi Suneagle,
            Thanks for your help. We live North West France.
            We have 6 x 250 watt solar panels
            MPPT controller 60 amp charging
            Inverter of 2.5kw
            100amp battery charger via generator (12volt)
            So as both the battery charger and inverter are 12v volt, for this reason i wish to keep it as this system really.
            I am a basic sparky so batteries etc are a bit of an unknown to me.

            Comment


            • #7
              Originally posted by Thomastheo1 View Post
              The system has been running for about 1 1/2 years like this as it was our holiday home until recently (now here full time) do you think it would have done any damage?
              More than likely, after 1 1/2 years of unequal charge/discharge cycles, yes. Look for the inside batteries to be affected most. Really you should consider a 48V system if you plan best use of your high Ah capacity bank. (read, http://www.solarpaneltalk.com/showth...Battery-Design and http://www.solarpaneltalk.com/showth...-Size-Tutorial ) Would be good to evaluate each individual battery and reconfigure as SunEagle suggests with the best eight batteries. Investing in a new 48V charger and inverter now could save you many headaches (and money) in the future.

              Comment


              • #8
                Originally posted by Thomastheo1 View Post
                Hi Suneagle,
                Thanks for your help. We live North West France.
                We have 6 x 250 watt solar panels
                MPPT controller 60 amp charging
                Inverter of 2.5kw
                100amp battery charger via generator (12volt)
                So as both the battery charger and inverter are 12v volt, for this reason i wish to keep it as this system really.
                I am a basic sparky so batteries etc are a bit of an unknown to me.
                I understand your desire for a 12 volt system since you already own equipment set up for it.

                Just be aware that while your batteries have worked for you the last 1 1 /2 years it sounds like you only used them sparingly. Now that you plan on being there year round you will begin cycling them more often which can quickly reduce their life.

                When the batteries do start to fail you may want to consider going to a higher voltage inverter and FLA type 6 volt batteries that can be wired in series. This arrangement should get you more life from your battery system due to them not being all wired in parallel.

                Upgrading your inverter and charge controller to higher voltage will be less expensive then replacing all those batteries wired in parallel as often.

                Comment


                • #9
                  Thanks again,

                  I have looked at the threads suggested and although "sunkings" is complex I understand where he is coming from. Which takes me onto my next problem. With the same power station described before, I intend on using it on a small house yet to be built, the lighting I wish to use only 12v led scheme which I am confident with.
                  However the rest of the power ( 240v ) will come from inverters. I am intending to use small inverters for each area of power required ie main room to power tv ( 35w led ) and other small consumption things to be used separately, then up size for kitchen,bedroom ( hairdryer) and use on off switches for these on the wall of each room thus meaning that they will only be on when required.

                  Would this be the way that you would attempt it. Just to clarify, there is no mains electric here and for the time being as we have limited funds 12v equipment is all I have !!

                  Comment


                  • #10
                    Originally posted by SunEagle View Post
                    I understand your desire for a 12 volt system since you already own equipment set up for it.

                    Just be aware that while your batteries have worked for you the last 1 1 /2 years it sounds like you only used them sparingly. Now that you plan on being there year round you will begin cycling them more often which can quickly reduce their life.

                    When the batteries do start to fail you may want to consider going to a higher voltage inverter and FLA type 6 volt batteries that can be wired in series. This arrangement should get you more life from your battery system due to them not being all wired in parallel.

                    Upgrading your inverter and charge controller to higher voltage will be less expensive then replacing all those batteries wired in parallel as often.
                    Sorry SunEagle i didnt see you reply earlier. Thank you for this, it seems the way to go for us in the future.
                    If you have any further advice for us for the house, i would be very grateful.

                    Comment


                    • #11
                      Originally posted by Thomastheo1 View Post
                      Thanks again,

                      I have looked at the threads suggested and although "sunkings" is complex I understand where he is coming from. Which takes me onto my next problem. With the same power station described before, I intend on using it on a small house yet to be built, the lighting I wish to use only 12v led scheme which I am confident with.
                      However the rest of the power ( 240v ) will come from inverters. I am intending to use small inverters for each area of power required ie main room to power tv ( 35w led ) and other small consumption things to be used separately, then up size for kitchen,bedroom ( hairdryer) and use on off switches for these on the wall of each room thus meaning that they will only be on when required.

                      Would this be the way that you would attempt it. Just to clarify, there is no mains electric here and for the time being as we have limited funds 12v equipment is all I have !!
                      You are on the right track. You first determine how many watts each item uses and then determine how many hours in a day they are used. You then need to total all of them up and then maybe add another 25% unknown watt hours. There is a meter call "kill a watt" which allows you to measure the wattage each "plug in" item uses. That helps you get an actual wattage instead of an estimated wattage.

                      You will be surprised how quickly a few items add up especially high wattage items like a hairdryer, coffee pot, heater, kitchen appliance, etc. Even just using a couple of those for a few minutes a day adds a lot of watt hours to the total.

                      To determine the true size of your battery system requires you to first have a real good understanding of your watt hour load. Then you will understand how much that load will cost you to run off of batteries.

                      Comment


                      • #12
                        Originally posted by Thomastheo1 View Post
                        I have looked at the threads suggested and although "sunkings" is complex I understand where he is coming from. Which takes me onto my next problem. With the same power station described before, I intend on using it on a small house yet to be built, the lighting I wish to use only 12v led scheme which I am confident with.
                        However the rest of the power ( 240v ) will come from inverters. I am intending to use small inverters for each area of power required ie main room to power tv ( 35w led ) and other small consumption things to be used separately, then up size for kitchen,bedroom ( hairdryer) and use on off switches for these on the wall of each room thus meaning that they will only be on when required.

                        Would this be the way that you would attempt it. Just to clarify, there is no mains electric here and for the time being as we have limited funds 12v equipment is all I have !!
                        Just another thought.....
                        Keep in mind the heavier gauge wire you'll need to push 12V. Depending on distance involved you may be better off with a small inverter. Wiring costs could come way down.

                        Comment


                        • #13
                          Thanks FloridaSun and SunEagle,

                          Thinking ahead on the plan of the house, and i understand with what you are both saying with using larger volt systems, but confused about using 6volt batteries to achieve this.

                          Comment


                          • #14
                            Originally posted by Thomastheo1 View Post
                            Thanks FloridaSun and SunEagle,

                            Thinking ahead on the plan of the house, and i understand with what you are both saying with using larger volt systems, but confused about using 6volt batteries to achieve this.
                            You can purchase 6 volt batteries with a higher AH rating then your 12 volt batteries. You would wire the 6 volt ones in series to get a higher voltage battery bank. 2 in series would get you a 12 volt system, 4 would get you a 24 volt and 8 would get a 48 volt system. When you wire them in series you will get the same AH rating but the voltage adds up.

                            You can wire your 12 volt batteries in series to get a higher voltage system but the problem is that they are only rated 110AH which will limit your system output.

                            Going with a lower voltage battery with a higher AH rating allows you to build a bigger battery system. You can also get the batteries as low as 2 volts and high AH rating but a 6 volt battery is pretty easy to get.

                            Comment


                            • #15
                              Originally posted by Thomastheo1 View Post
                              Thanks FloridaSun and SunEagle,

                              Thinking ahead on the plan of the house, and i understand with what you are both saying with using larger volt systems, but confused about using 6volt batteries to achieve this.
                              6volt?? I thought you had "10 12v 110ah batteries" as your first post says.

                              Comment

                              Working...
                              X