solar panels for 48 volt battery charging

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Comments

  • mcgivormcgivor Posts: 1,899Solar Expert ✭✭✭✭
    It all depends on what the SG of the electrolyte was on fill, if it was 1.265 then that is what it is, no amount of charging will increase it above that, but will harm them if overcharged ( equalized ) excessively.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
     Could they be putting less electrolytes in the golf cart batteries now than they had been in the past ?
     I dipped a golf cart and my trailer battery’s all 4 and 5 years old . 
     The golf cart read 1274/ 75 on the 2 battery’s I checked . 
     My trailer battery’s are at 1300sg but get EQ every 30 days buy the solar charge controler . 
      
     Would a battery with a SG of 1265 when new still put out the same ah and last as long as a battery with 1275 or better ? 
  • mcgivormcgivor Posts: 1,899Solar Expert ✭✭✭✭
    Read this thread, sometimes strange things happen, to be honest I'm not sure exactly why, but SG readings can increase. ....apparently.
    http://forum.solar-electric.com/discussion/353422/high-specific-gravity-unexplained#latest
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    Wow that seems weird , good read . 
     Funny thing is all the battery’s I have have been at 1275 or better from day one , and are still there . 
     Just when you think you have got something figured out , they change the rules . 
  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    So the question is is 1265 a good number for a new battery , it never was before ? 
     I’m pulling all the battery’s and taking them home . 
      Then calling penn on Monday and talking to them . 
       I guess if all the battery’s stay at 6 3.8 or above this week and the SG is close I will move to  tying them into the system . 
     If that goes well I’ll get the other 8 battery I have on hold 

  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    The chart above comes from rolls  1255 1275 SG is a full charge reading , news to me , but what do I know .
      Maybe I’m just Paranoid , I’ve just never seen SG readings this low on a new battery .
      This baddery thing is like vooodo , maybe I need to get a witch doctor in with some chicken blood and maybe a  shrunken head or two .  This makes me feel a little better 
  • mcgivormcgivor Posts: 1,899Solar Expert ✭✭✭✭
    Electrolyte SG at initial fill may differ depending on the intended application, with the relative short time off grid PV charging sources have been around, battery manufacturers have adapted to the industry, probably at a cost due to warranty claims, because their charging recommendations were based on grid charging, not the limited opportunity charging in PV applications. There are advantages and disadvantages of having a lower SG fill for example, lower capacity but longer life expectancy. My thoughts are that the more reputable manufacturers will supply whatever is best based on particular application, general purpose use batteries on the other hand may just use a single SG fill, a one size fits all,  because the batteries are sold by retailers who provide no technical support.


      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    Well I talked to penn to day. 
     The tec person (lady) checked out the numbers and the 7 /18 #  was the start of the July run .
     So she said they were new.
     The SG could be off 25 points and would be considered new. 
     6 3 .2 and up is a good reading . 
     And she wasn’t worried at all , the voltage  SG readings were all ok . 
      But she wasn’t paying for them .
     I will check them out more  tomorrow when I have time . 
     She all so said it would be impossible for them to send out a pallet of bad battery’s 
     maybe 1 out of 500 come back bad but that is a 1 year warranty. 
       I need a witch doctor 
  • EstragonEstragon Posts: 2,453Registered Users ✭✭✭✭
    I was buying it up until the "impossible to send out a pallet of bad batteries" bit. Was it a young person by any chance?

    My old brain comes up with a higher, not lower, probability of a pallet being defective rather than a random quantum fluctuation. That's why they date stuff, so the drunk guy who works on the loading dock and pissed in the cells after the friday afternoon card game gets canned.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
     EST.  I  thought the same thing , I was more worried about not so much bad battery’s but a change in the product where it would not last as longhorn or. Work so well . 
     I’ve been getting good service  from this battery with a one year warrantey ? 
      I’ve allways checked voltage at the store , then charged the battery’s before I put them in service.
      I didn’t have my volt meater with me and I was in a hurry . 
     When I checked the voltage and Sg I was surprised . 
     I charged them for 2 hours now the ones I checked seem ok volt are holding 6 3.8 / 6 3.9 
     sg is much better , all battery’s are 1265 or a little better . 
       
     Let me ask this if the battery’s a bad will they die in a year? 
     
       Do you think I can get 2 years out of not so good battery? 
     I plan to baby them . 
      I would like to see 3 plus years but 3 years wouldn’t be the worst thing ? 
     What do you think ? 
  • mcgivormcgivor Posts: 1,899Solar Expert ✭✭✭✭
    The life expectancy would be directly proportional to the use or abuse, the correct or incorrect charging, maintenance or lack thereof and operating temperature, to mention a few . Becoming obsessed with trying to achieve perfection will drive someone crazy, what is 6.38V or 6.39V, is one 6.384V  the other 6.386V rounded out to the resolution of the meter? What is the accuracy tollerance of the meter itself +/- 1%?

    There will always be minor variations between batteries these have little effect on overall performance, every so often there will be a dud, or lemon if you want, usually a defect in manufacture, which will probably reveal itself pretty soon, that's what the warranty coverage is for.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • EstragonEstragon Posts: 2,453Registered Users ✭✭✭✭
    At good SG and voltage, I'd probably keep them. Hardened sulfate would stay on plates, not end up in electrolyte.

    If a battery is bad, you just know it will go bad in warranty + one day, either by design or just luck!

    Seriously though, if there's a major defect (that would likely work for warranty purposes, such as bad welds, contaminated electrolyte etc), I'd expect it to show in a year or less. After that, you'd be hard pressed to prove you didn't cause the failure anyway.

    You probably know more about batteries than 90% of battery buyers (and likely the "tech"), so I'd say odds of good battery life aren't bad.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    I think I will just throw the 2 g in the wind and see what happens.
     I’ve been working sun up to sun down .
     I’m going to study the # on Thur fri and if they are ok I’ll move to the next step and try to hook them up.
       Say what size fuse do I need for 2/0 inverter cable my inverter is a outback 36 / 48 v I need a fuse for my battery’s 
  • jonrjonr Posts: 1,002Solar Expert ✭✭✭✭
    > Would a battery with a SG of 1265 when new still put out the same ah and last as long as a battery with 1275 or better ?

    If the initial fill was 1.265, it should put out less AH but have longer life.     If it's 1.265 because of already having some permanent sulfation, then less AH and less life.
  • Raj174Raj174 Posts: 611Solar Expert ✭✭✭✭
    wellbuilt said:
    I think I will just throw the 2 g in the wind and see what happens.
     I’ve been working sun up to sun down .
     I’m going to study the # on Thur fri and if they are ok I’ll move to the next step and try to hook them up.
       Say what size fuse do I need for 2/0 inverter cable my inverter is a outback 36 / 48 v I need a fuse for my battery’s 
    If you have an Outback Flex power FP1, then it has a 175 amp inverter breaker so you will need a 175 amp fuss for each battery string.

    Rick
    12 x 300W Renogy PV, MNE175DR-TR epanel modified, MN Classic 150, Outback Radian GS4048A, Mate3, 54.4V 207AH HI Power LiFePO4 no BMS, 4000W gen.
  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    Jonr I guess it’s a crap shoot . Thanks for the breaker sizing 
  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    Thanks for the breaker sixeing rick 
  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    I’m looking at a 175 amp battery fuse block , but it’s rated for 58 volts  EQ is 64 volts . 
     Would this be allwrite . 
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