SW4024 power Issues

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  • Marc Kurth
    Marc Kurth Solar Expert Posts: 1,144 ✭✭✭✭
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    Your batteries are heavily sulfated. Equalize them for 8 hours @ around 31v (higher if cold) then drag them down with a load. Unleash your inverter to hit them at 90 amps or higher until full. Full is defined at a current draw of 2 amps when charging at 28.6v to 28.8v.
    Recheck your standing voltage after at least 4 hours of being idle. If it has not reached 6.4v, do it all over again.
    If your batteries spent any appreciable amount of time below 5.2v, they may need to go through a deep discharge recovery process, which requires a special charger.
    Marc
    I always have more questions than answers. That's the nature of life.
  • Photowhit
    Photowhit Solar Expert Posts: 6,003 ✭✭✭✭✭
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    ... Equalize them for 8 hours @ around 31v (higher if cold) ...
    Can you go that high with lifeline agm  batteries...
    ...I suspect you can, I know it's your end of the pool.  Just checking to see if you caught the type.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,750 ✭✭✭✭✭✭
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    Your batteries are heavily sulfated. Equalize them for 8 hours @ around 31v (higher if cold) then drag them down with a load. Unleash your inverter to hit them at 90 amps or higher until full. Full is defined at a current draw of 2 amps when charging at 28.6v to 28.8v.
    Recheck your standing voltage after at least 4 hours of being idle. If it has not reached 6.4v, do it all over again.
    If your batteries spent any appreciable amount of time below 5.2v, they may need to go through a deep discharge recovery process, which requires a special charger.
    Marc
    Maybe, I have only seen this once where a cell opened up (like his graph) and was saveable. Won't hurt to try but a CSW  can only output 60A or maybe if a csw 4024 90a with a good size genset. Hmmm I think he has the grid, more options...
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • Marc Kurth
    Marc Kurth Solar Expert Posts: 1,144 ✭✭✭✭
    edited December 2019 #35
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    Photowhit said:
    ... Equalize them for 8 hours @ around 31v (higher if cold) ...
    Can you go that high with lifeline agm  batteries...
    ...I suspect you can, I know it's your end of the pool.  Just checking to see if you caught the type.

    Yes, Sir, I appreciate you checking to be sure I hadn't lost it :)   Lifeline is a Concorde product and my numbers are right out of the manual. In fact, we go clear up to 3v/cell under controlled circumstances for shorter durations, at a current limit of 5% of the battery C/20 rating. Yes, there is some babysitting involved with regard to temperature and excessive off-gassing.
    I am working on a set of (12) badly sulfated 12v 8D's, that arrived at my shop at around 5v and would not accept more than a 12% charged capacity. I have half of them at 80% to 82% so far. I believe that I can get most/all of them to about 85%. No miracles of course, but the hope is to get enough out of them to provide another year or two of service life. Maybe more with shallow cycling.
    Using a high charge rate after each 100% discharge capacity test is a critical part of the process. On an 8D, 150a to 200a works well.
    I always have more questions than answers. That's the nature of life.
  • stmar
    stmar Solar Expert Posts: 370 ✭✭✭
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    Correct, Lifeline manual specs 31 volts to equalize. Having problems getting my Conext SW4024 to go into Equalizing mode. Using the Combox and it has two fields, Equalize Now under the Control heading and Equalize Support under the Custom Battery Setting heading and it says the values cannot be changed. Do I have to enable Charger Override Enable/Disable under the Charger Settings to be able to engage the EQ modes?
  • stmar
    stmar Solar Expert Posts: 370 ✭✭✭
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    I got the EQ Support to change, had to change the Battery to Custom instead of AGM but still can get the EQ Now to work.
  • Marc Kurth
    Marc Kurth Solar Expert Posts: 1,144 ✭✭✭✭
    edited December 2019 #38
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    Your batteries are heavily sulfated. Equalize them for 8 hours @ around 31v (higher if cold) then drag them down with a load. Unleash your inverter to hit them at 90 amps or higher until full. Full is defined at a current draw of 2 amps when charging at 28.6v to 28.8v.
    Recheck your standing voltage after at least 4 hours of being idle. If it has not reached 6.4v, do it all over again.
    If your batteries spent any appreciable amount of time below 5.2v, they may need to go through a deep discharge recovery process, which requires a special charger.
    Marc
    Maybe, I have only seen this once where a cell opened up (like his graph) and was saveable. Won't hurt to try but a CSW  can only output 60A or maybe if a csw 4024 90a with a good size genset. Hmmm I think he has the grid, more options...

    I do agree about not being able to save a battery with an open cell. I had not seen the graph. Good catch!
    I was going on the assumption that all batteries were simply a uniform 6.2v. Yep, I have seen batteries that could support a 5 amp load, but would go to 0v with a 20 amp load.
    About the only thing that I have seen that would cause an intermittent cell is a cracked weld on a bus bar between cells. That is extremely rare on a stationary application that is 5+ years old. A simple redneck load test would flush that out in a hurry.
    I always have more questions than answers. That's the nature of life.
  • stmar
    stmar Solar Expert Posts: 370 ✭✭✭
    edited December 2019 #39
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    I got it to start Equalizing, 31.2 volts @ 8.3 amps. I will keep an eye on it and go a few hours. Had to do it from the SCP instead of the Combox which is strange but I probably did something wrong.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,447 admin
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    When the bank is under heavy load (and/or charge), check each battery with a DMM... Ideally, they should all match, if you have a weak or failing cell, you will quickly find the one (or more) bad guy(s). You are looking for differences...

    Of course, if everything is equally weak (i.e., equally sulfated)--They may all match, and the bank is still bad.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,750 ✭✭✭✭✭✭
    edited December 2019 #41
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    Your going to have to hit that with more amps or it is just a burning time. You are grid tied right???

    I was thinking about your graph and this is the problem with a 24V system. There is not enough headroom voltage wise to keep the xanbus (the network)  logging the voltage. Your graph may not be accurate and a cell was not opening up. Need to get a logging voltmeter.

    When I test with something like combox, gateway or the config tool, I run on a separate xanbus to make the data meaningful. Also 48V inverters will tend to keep xanbus operating after LVCO, unless the cell is opening.
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • stmar
    stmar Solar Expert Posts: 370 ✭✭✭
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    Just wanted to share this with other Schneider Conext SW4024 users, thanks to another forum member. Equalizing times out after an hour so you have to re initialize to keep it Equalizing.
  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,750 ✭✭✭✭✭✭
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    There are other ways of course if you read the manual.
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

  • Marc Kurth
    Marc Kurth Solar Expert Posts: 1,144 ✭✭✭✭
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    stmar, Based on your email, It sounds like you are making progress on regaining capacity. Roughly how big is the refrigerator load?
    I always have more questions than answers. That's the nature of life.
  • stmar
    stmar Solar Expert Posts: 370 ✭✭✭
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    stmar, Based on your email, It sounds like you are making progress on regaining capacity. Roughly how big is the refrigerator load?
    Per their literature the 24 volt RF16 uses 20 amp hours per day. 2 - 24vdc Danfoss Compressors, each protected by 7.5 amp 24vdc breaker and I have them on a 15 amp breaker at the battery bank. Max current draw running = 4.5 - 5 amps, Max current draw starting = 10 amps.


  • Marc Kurth
    Marc Kurth Solar Expert Posts: 1,144 ✭✭✭✭
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    OK, so running the overnight with a very small load and holding above 25v is an improvement. Let's see if they come up some more. Don't be afraid of running your EQ voltage up to 33v-34v for 2-4 hours.
    I always have more questions than answers. That's the nature of life.