Announcement

Collapse
No announcement yet.

Battery replacement/upgrades?

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

  • Battery replacement/upgrades?

    I've got 2 55hr dc sla 12v batteries (they are in parallel now, but will be in series after I get a new inverter). I have 3 x 100W mono panels now (in series), and a 4th when I move. From what I've gleaned from this site I can not add any more batteries to the system because the 2 I have now are already a couple of weeks old. What happens if a battery in a 10 bank system goes bad? Surely it must have to be replaced. I can't understand replacing all the batteries if one goes bad. Is that the case though?
    900W, 40A MPPT, 230AH FLA,24V Samlex 1500W

  • #2
    Battery addition / replacement. If the batteries are pretty close in age, it may be better to replace the one dud, and hope for the best. When a battery in a 3 year old setup dies, replace it and plan on it's brothers going bad soon too, start shopping.
    And look for batteries in the right amp hour rating. if you are needing 400 ah of storage, buy 2v or 4v cells @ 400ah. and wire in series, not 4 parallel 100ah batteries..
    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
      Try to look at a battery bank as something similar to a basket of apples. One goes bad and the others are ok but still affected by it. Now you get rid of the bad apple and put a new one in.

      Unfortunately the rest of the apples are not as healthy as the new one so they actually reduce it's health so it won't last as long as it should have if it was surrounded by all healthy apples.

      Batteries work the same way. a good or new one can be hurt by older or weak ones.

      You can replace one battery in a bank but just be aware that it will not last as long as it should.

      Comment


      • #4
        Thanks all, and ouch. Back to plan A...a 2nd system later.

        What is the advantage of chaining 12 2V 100AH cells to make a 24V battery over using one 100HR 24v battery? Is it the cost, the weight? Does the one bad apple rule hold with 2v cells: one dies replace them all?
        900W, 40A MPPT, 230AH FLA,24V Samlex 1500W

        Comment


        • #5
          Originally posted by Gdwats View Post
          Thanks all, and ouch. Back to plan A...a 2nd system later.

          What is the advantage of chaining 12 2V 100AH cells to make a 24V battery over using one 100HR 24v battery? Is it the cost, the weight? Does the one bad apple rule hold with 2v cells: one dies replace them all?
          Well using a single 12v 100Ah battery will work. It is heavy and expensive but can be done.

          But if you need more than 100Ah and still want a 12v battery system, a better way to build it is to use lower voltage cells (2, 4 or 6v) that have the Ah rating you need and wire them in series.

          The simple fact is the higher the voltage and Ah rating the heavier the battery. And since there are very few options of high Ah rated 12v batteries the more expensive they get.

          Comment


          • #6
            I will be 24v. I am getting a 24V pure sine inverter soon
            Last edited by Gdwats; 08-10-2017, 03:33 AM.
            900W, 40A MPPT, 230AH FLA,24V Samlex 1500W

            Comment


            • #7
              For this "go-around" I'd say keep the 2 batteries you have, and when you get the 24V inverter, wire them in series, reset your charge controller to 24V and see how it comes out.
              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


              • #8
                Sounds sound, thanks.
                900W, 40A MPPT, 230AH FLA,24V Samlex 1500W

                Comment


                • #9
                  I have 2 12v batteries in series for 24v now. What happens if a 3rd 12v batteries is hooked in series resulting in 36v? Can you use both parallel and series somehow?
                  900W, 40A MPPT, 230AH FLA,24V Samlex 1500W

                  Comment


                  • #10
                    Short answer. No.

                    For that matter finding a charger or inverter rated for 36v will be hard.

                    What is the reason for adding a 3rd battery?

                    Comment


                    • #11
                      Cause I only have 55hr
                      900W, 40A MPPT, 230AH FLA,24V Samlex 1500W

                      Comment


                      • #12
                        Originally posted by Gdwats View Post
                        Cause I only have 55hr
                        Sell those little batteries and get something larger. Stop playing with little batteries when you want a large battery.
                        OutBack FP1 w/ CS6P-250P http://bit.ly/1Sg5VNH

                        Comment


                        • #13
                          Wanna buy a battery?
                          900W, 40A MPPT, 230AH FLA,24V Samlex 1500W

                          Comment


                          • #14
                            Initially I was going to have 3 x 55ah in parallel for 165AH at 12v. About right for my 20Amppt and 3 panels. Now the batts are in series and I can't add AHs or exceed 24v. The 24v inverter arrives monday. Seems it would have made more sense to buy a 3rd battery all in parallel vs the cost of the new inverter.
                            Last edited by Gdwats; 08-12-2017, 08:21 PM.
                            900W, 40A MPPT, 230AH FLA,24V Samlex 1500W

                            Comment


                            • #15
                              Originally posted by Gdwats View Post
                              Initially I was going to have 3 x 55ah in parallel for 165AH at 12v. About right for my 20Amppt and 3 panels.
                              Hold the bus, something is not right. .

                              Let me make sure I have this right. You have:

                              3 x 100 watt panels wired in series for 300 watts and looking to add a 4th 100 watt for 400 watts right?
                              20 amp MPPT Controller?

                              If that is a True Statement, your math really sucks. A 20 Amp MPPT Controller Input Power Limit is 250 watts at 12 volt battery, and 500 watts at 24 volt battery. Were in the heck did you come up with a 12 volt system? Allow me to answer. You are stuck inside a 12 volt toy box. That is why you bought 12 volt batteries instead of 6 volt batteries.

                              Sorry to say but you screwed up just about everything you possible could have. You used battery panels when you should have used GT panels, too small of a charge controller, wrong batteries and battery voltage.

                              The least I can do for you is tell you how to fix what you have, and forget the rest. Get a 24 volt Inverter, and wire your two batteries in series for 24 volts and call it done. You CANNOT ADD the 4th panel if you insist on playing inside a 12 volt Toy Box you trapped yourself in. Only way you can stay at 12 volts and add a panel is if you replace the 20 amp Charge Controller with a 40 amp model.

                              Anyway the proper battery voltage and capacity for a 300 watt MPPT System is:

                              12 volts @ 200 to 250 AH (with 30-Amp Controller), or 24 volts @ 100 to 125 AH (with 15-Amp Controller)

                              For 400 watts

                              12 volts @ 300 to 375 AH (35-Amp Controller), or 24 volts @ 150 to 185 AH (20-Amp Controller)
                              Last edited by Sunking; 08-13-2017, 01:25 PM.
                              MSEE, PE

                              Comment

                              Working...
                              X