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  • Voltage Ripple.

    My Victron pure sine wave inverter would not operate from the (24v) DC current supplied by my (old) batteries giving me the error message "Voltage ripple on the DC input exceeds 1.25Vms. Can anyone explain what this means to me in too technical terms please?

    When I connected the same 4 year old batteries in a series/parallel configuration to supply 12volts to my other cheaper inverter it works fine.

    I know that the batteries were not charged properly for over a month due to a bad connection from the CC, so perhaps they are pretty well ruined.

  • #2
    Normally that message would be seen if you tried to supply the inverter from something like a rectifier without batteries or from a battery bank which is being pulse charged. It means that while the inverter is running the difference between the highest battery voltage and lowest battery voltage over the course of one AC cycle is too high.
    In your case the cause of the ripple is most likely the current drain of the inverter itself because the internal resistance of your battery bank is too high.
    A cheap inverter would not warn you about that situation and let you keep on draining your batteries until the voltage dropped below the LVCO point and stayed there.

    Try looking at the voltage on the battery terminals with a DC and an AC meter setting. (You may have to add a series capacitor to get the AC ripple reading.)

    Then plan to replace your batteries.
    SunnyBoy 3000 US, 18 BP Solar 175B panels.

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    • #3
      ditto

      pretty much just what inetdog just said. The batteries are not able to supply enough surge power to prevent ripple from occurring, which will result in AC waveform distortion. Batteries are Too Old or Too Small.
      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

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      • #4
        Originally posted by inetdog View Post

        Then plan to replace your batteries.
        I have replaced the batteries already and am continuing to use the old batteries with the cheap inverter to run a second fridge during the daylight hours.
        Is there any way of reviving the old batteries? Looking on Youtube I see a few people claiming to have ways of revitalising old FLA batteries. Is desulfation a reality?

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        • #5
          Originally posted by Beanyboy57 View Post
          I have replaced the batteries already and am continuing to use the old batteries with the cheap inverter to run a second fridge during the daylight hours.
          Is there any way of reviving the old batteries? Looking on Youtube I see a few people claiming to have ways of revitalising old FLA batteries. Is desulfation a reality?
          There are things that you can try, as long as you do not expect great or lasting results. All controversial.
          The consensus is that in some cases electronic desulfators may do something in some cases.
          Chemicals will have a short term effect at best.
          if you are happy with getting only 50% of the original capacity you might have a chance.

          In short, the prospects are poor. Do not trust YouTube, especially when it is too good to be true
          SunnyBoy 3000 US, 18 BP Solar 175B panels.

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          • #6
            As discussed, finding a way to reduce the battery internal resistance is the problem. However
            you may also have some measurable voltage drop in the wiring from the batteries to the
            inverter. Part of that voltage is ripple (across the wire resistance), so getting that voltage
            low will help. Bruce Roe

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            • #7
              Originally posted by Beanyboy57 View Post
              I have replaced the batteries already and am continuing to use the old batteries with the cheap inverter to run a second fridge during the daylight hours. Is there any way of reviving the old batteries? Looking on Youtube I see a few people claiming to have ways of revitalising old FLA batteries. Is desulfation a reality?
              Are you really sure they are sulfated in the first place? What are the SG's like in each cell? Could they just be badly unbalanced internally? Have they ever received an EQ charge, and if so has that been done to each one individually - I'm assuming some paralleled 12v batts...

              Yeah, it could be they are just tired.

              However, I'm treading on dangerous ground here - any word about desulfation is usually the red-flag for hype. However, I have brought back a 7 year old shelf-queen that was totally sulfated:

              http://www.solarpaneltalk.com/showth...on-testing-now

              The real question here is: did the desulfating waveform (it is a freq sweep, and not high voltage spikes) help at all during this process, or was it JUST the normal action of a very smart charger?

              At first, I was very leery of even thinking about Battery Minder when I saw the "desulfation" feature plastered on it. For me, that was anti-productive! BUT, when I saw in the docs how they go to great lengths to teach people how to use a hydrometer along with SG values to see if/when they should just give up the ship, that got me thinking, so I tried it.

              They don't tout this thing as being a total miracle worker for bringing back trash, and basically tell you so. What I found was a charger that really seemed to be right on top of things, even without the desulfation stuff, so I tried it. Along with great docs, and the importance of validating it's work by measuring for improved SG's, rather than just straight voltages made me think that perhaps they aren't trying to pull the wool over my eyes.

              Anyway, just a thought if you want to give the Battery-Minder a try. Also look at the Tecmate-Optimate 6. I also like this since the oscillating absorb (13.7 to 14.4) tends to balance cells without having to do a total eq especially on agm's - along with testing all along the way and afterwards impressed me. I made them prove it by purposely discharging my own 12v / 2v cells Pb battery bank made out of Cyclons, and it worked very nicely for that.

              Now if I could only put the Optimate and the Battery Minder together like a peanut-butter cup, I'd be ecstatic.

              Anyway, that's my thought. I can't *prove* that the desulfation of the battery-minder brought back my totally sulfated agm, but at the very least all I can say is that it didn't hurt!

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              • #8
                Battery minder

                Originally posted by PNjunction View Post
                Are you really sure they are sulfated in the first place? What are the SG's like in each cell? Could they just be badly unbalanced internally? Have they ever received an EQ charge, and if so has that been done to each one individually - I'm assuming some paralleled 12v batts...

                Yeah, it could be they are just tired.
                They were connected in series for 4 years in a 24v set up. They have been equalised at various times but it was just for the last month or 6 weeks of winter/spring that there were used for 24 hours a day without a proper recharge or equalisation that seemed to cause the voltage ripple problem for the Victron Inverter charger.

                They are now connected to a cheaper 12 volt inverter that is why I had to parallel/series them to get the 12 volts required.
                I'll purchase a temperature compensated hydrometer and the Battery Minder 2012 and give it a try. I am super excited to think that I can bring these batteries back from the brink (perhaps)!
                Thanks a million Pnjunction!
                P.S. Looked up pnjunction on google, it was an elightning read.

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                • #9
                  Originally posted by Beanyboy57 View Post
                  I'll purchase a temperature compensated hydrometer and the Battery Minder 2012 and give it a try. I am super excited to think that I can bring these batteries back from the brink (perhaps)!
                  They have 24, 36, and 48v models too. But I think working on a single 12v battery at a time might be the best option.

                  Ok, just know that only 2A, you may have to bulk charge them first, otherwise you may end up tripping the 20 hour bulk timeout too many times. In my case, I watched it time out, rest/test, flag the "load light / timeout", and drop back for another 20 hour bulk (which was only a few more hours actually) before advancing to absorb and extinguishing the load light. Bad cell also went away.

                  It comes with an external ambient temp-comp sensor, but if you really want to do it right, get the "ATS" aka at-the-battery temp sensor. There is also the 12248 model, which has a higher 8A output if desired. (mine had a tendency to fall back to gel/2a at times a few years ago, so maybe I'll try again with a later model).

                  It is pretty cool how they instruct you to baseline your SG's first, and how to do it in the first place!, follow along to watch for progress, and just recycle if no progress is being made.

                  Still, we can't prove anything, so that's the hard part and why I tend to tone down the desulfation thing. Even without it, I like what they are doing, along with Optimate.

                  Let us know what happens! I'll be interested to see if your batts are just worn out or if an improvement is noticed.

                  TIP: Make SURE the SAE connectors are tight! BM and Optimate's are better than most, but lately I've been cutting out ALL of my charger's sae connectors and putting on my own Anderson powerpoles just to be sure. Fixed a recalcitrant noco G15000 that way.

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                  • #10
                    BatteryMinder

                    Having issues with the BatteryMinder as they don't seem to like to sell products overseas! Hopefully they will respond to my email eventually.

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