solar panels for 48 volt battery charging

2

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  • Raj174Raj174 Posts: 611Solar Expert ✭✭✭✭
    wellbuilt said:
    EST I wi check the codes to be sure they are the same . 
     Sams club buys a new full Pallet at a time the guys tell me they should be all the same in new they sell a power every couple of weeks this time of year
     PW I’ve never had a core charge at sams club in my area ? 
     I have a lot of equipment and trucks and I’m buying batteries all the time I just save them up and take themto the recycler when they pile up. 
     I did notice that my battery’s went up this week ( figures) from 84 to 94 dollars it seems crazy a 10 dollar jump just like that . 
     3/4 plywood jumped from 21 to over 40 rollers in a year so 10 doesn’t seem so bad . 
      
     Mike sooooo your inverter is switching between charging and loads with a 3000watt genarator ? 
     My inverter can do that but guy are telling me that to much searching can Where out the contacts and
     
      Rick I have bought from them before I can ride up and pick up a unit . 
     I’ve been looking at the air cooled 5000 watt ,  Perkins 6125 watt water cooled , and a 10000 watt kabota .
      The Perkins seems to best fit my needs but it turns at 2300 rpms not the common 1800 rpms . 

    Ok, I thought they might be close to your location. I found them searching for a small diesel, but they're cost is a bit more than I could afford. Wound up buying a Kohler Pro5.2E 4500 watt gas powered portable. I read that they are a good quality generator, hope that's true. It will be delivered next week.
    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.
  • PhotowhitPhotowhit Posts: 4,606Solar Expert ✭✭✭✭
    wellbuilt said:
     PW I’ve never had a core charge at sams club in my area ? 
    WOW! where are you located. That's nuts. Do they pay you for recycling your batteries? Lead acid batteries sell for around 35 cents a pound in Missouri. Those 60lb golf cart batteries are worth around $20 as scrap.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • PhotowhitPhotowhit Posts: 4,606Solar Expert ✭✭✭✭
    Looks like they are getting 32 cents a pound for car batteries in your area, Not sure why  Sam's isn't asking for cores, maybe a local law and perhaps why they have increased the cost. Worth checking. Maybe if you have a Merchant account or something;

    https://www.greenblottmetal.com/scrap-metal-prices
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • EstragonEstragon Posts: 2,453Registered Users ✭✭✭✭
    FWIW, my Outbacks don't switch between charging and loads, they throttle charging current if/when more current is required by loads. I don't know exactly how they vary the current to the charger, but I don't think there are any contacts chattering and wearing out.

    The only contacts I know of are in the transfer switch, which would only fire once when generator power is qualified, and again when going back to inverter power.
    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 ✭✭✭
    Ouch they got me today , the battery’s just jumped from 84 to 94 and they hit me with a 5 dollar core charge. 
     I do get 150 bucks for 5 battery at the recycler . 
  • PhotowhitPhotowhit Posts: 4,606Solar Expert ✭✭✭✭
    wellbuilt said:
    Ouch they got me today , the battery’s just jumped from 84 to 94 and they hit me with a 5 dollar core charge. 
     I do get 150 bucks for 5 battery at the recycler . 
    If it lessens the pain at all, I believe the core charge here was $18 each last time I bought some GC batteries about 2 years ago.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    Oooooo I picked up 8 gc215s put 8 on hold till next week . 
     They all had 7 18 on them it’s still June 618 ? Kinda funny 
     charged them up with a decent charger but 4 read very low for a battery that just came in and charged about 2hrs .
     4 with the same numbers read about 90% and came up to full charge in 20 seconds .
    the sg was very low even after charging 1250 1265   A few cells read 1275 but not A lot 
     I have 4 year old battery that are reading better . 
     I’ve never even seen a battery off this much even after 4 years ?
     What should I do now. ? 
           I picked from the center of the palet . 
    I don’t think the charger and my sg reading could be wrong ,
     I may try a second charger ? 
     What is a good resting voltage on a 6 volt battery ? 6.4 ? I read my other system in 12 volt . 
      
  • mcgivormcgivor Posts: 1,899Solar Expert ✭✭✭✭
    Seventh week 2018 perhaps ?
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    That would be July ? 
     They came in on Thursday I picked them up to day . 
     It’s still June 
  • mcgivormcgivor Posts: 1,899Solar Expert ✭✭✭✭
    Seventh week would be February 
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    EST I must of read the charging and load balance wrong or just did not understand what it was saying ? 
     I’m not to good with the  Technology part of this . 
     I’m sure you are write ? But I will reread the manual again . 
     I more worried about my battery problem now . 
  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    🤯 that makes sense I don’t know why I didn’t think of that .
     But all my battery  experience has always been months  go figure  
     Wouldn’t think they would be delivering 4 month old battery’s but that would explained the low charge and sg I think . 
      But still don’t like it . 
  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    What is a good feasting voltage for the 6 volt gc battery’s 
  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    Resting 
  • EstragonEstragon Posts: 2,453Registered Users ✭✭✭✭
    ~6.3-6.4v would be about fully charged resting.
    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 ✭✭✭
    Will check it out in the AM . Thanks
  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    Ok my voltage match’s the SG .
     Low volts are 6.27 hi volts are 6.32  all 8 where charged to full yesterday , some battery’s read full in under a  minute 
     some took 2 hours . 
     The charge is not the best but works good on 12 volt stuff .
      What are my  options ? 
     I could just return them .
      I could try to get the battery’s to Equalize but I don’t think I should really have to fight with them to much . 
       I guess I could cherry pick the best of 8 and keep swapping out battery’s till I get some better numbers , 
     but they won’t have matching numbers .
      Don’t really have time for this ? 
  • EstragonEstragon Posts: 2,453Registered Users ✭✭✭✭
    The voltages don't sound bad, but IMHO there's a chance some of the batteries sat in storage at elevated temps. For example a pallet in a semi trailer which heats up in daytime. Batteries in the middle of the pallet might stay reasonably cool while those on the outside heat up. Doesn't matter for a pallet of jeans or socks, but does for batteries, and I don't know that Walmart distribution centers would have special storage for batteries. The store might get fresh stock weekly, but who knows what happens in the distribution system. You'd think batteries in the center of the pallet had been there since shipping from the factory, but...
    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
  • mcgivormcgivor Posts: 1,899Solar Expert ✭✭✭✭
    edited June 23 #50
    Variations between battery voltage will always exist, even if manufactured on the same day, doing an equalization with all in series or series/parallel, whatever your particular configuration is, will ballance cells, even then voltage will differ slightly, as long as SG readings are consistent across all cells, that's about as close to perfection as could be expected. The date codes are generally important to ensure there is not a wide variation in age between individual batteries, which may have been in storage, no point in attempting to achieve perfection, my opinions others may differ.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • EstragonEstragon Posts: 2,453Registered Users ✭✭✭✭
    I mostly agree with @mcgivor - it's what you said about there being a wide variation in SG initially that makes me wonder. Doing an EQ on new batteries is a good idea anyway, and should give an indication if some of them are likely to be a problem later.
    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 have no way to EQ all the battery’s at once . 
     I picked a battery that had the lowest voltage 6 .22  the sg   Taking the reading on  cell closest to the post  read 1250 next cell was a 1260 next was 1265 . ? 
      I buy these a lot for golf carts and they read all around 1270 and up . 
     My trailer has 2 gc battery that are 4 years old and read about the same for SG for 6 cells and are due for a eq from my solar charger ? 
     How hi a voltage do I need to see for manual eq and how long . ? 
  • mcgivormcgivor Posts: 1,899Solar Expert ✭✭✭✭
    Follow the manufacturers recommendations, if available, but generally around 64V for a 48V nominal system, current will be high initially but will drop once the target voltage is reached, depending on charger this process could take between 1 and approximately 3 hours.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    So for 1 6 volt gc battery I would like to charge at 8 volts ? 
     I only have a 6 volt 30 amp manual charger on hand , the charger out put was 30 amps and dropped to 24 amps in 10 minutes . 
     I’m thinking 24 amps into a 215 ah battery is ok . 
     I will check SG every 20min 
  • mcgivormcgivor Posts: 1,899Solar Expert ✭✭✭✭
    Most generic manual  chargers not designed to actually perform an equalization,  many tend to runaway with voltage, exceeding the target, whilst others are unable to reach the target voltage. Charge controllers on the other hand, at least the better ones, are designed with an algorithm specifically for the purpose, Be careful it's easy to do harm, despite good intentions.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    Will I be ok if I watch for heat and voltage . 
     The battery is  slightly warmer than the other ones barely noticeable 
     And the voltage is holding at 8.8 now 
     the SG has all come up to 1265 now 
     would it be ok to run the SG to 1275 and then quit . 
     How much voltage would be to much ? 
  • BB.BB. Posts: 27,574Super Moderators admin
    8 volts would be a good maximum.

    Watch current, bubbling, and temperature.

    Setting 5 to 10 amps would be good for a single 200ah 6volt golf cart battery to equalize. 2.5% to 5% rate of charge for EQ.

    You want fizzing, not a rolling "boil". Even 2.5% rate of charge can overheat a battery on EQ if 12 to 24+hours of continuous charging.

    Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
    I ended upwith  8.8 volts fo about 2 hrs the battery was a little warm , it’s 57o here 
     SG never went above 1265 1268 maybe ? 
     It was bubbling at a good rate but  deafly not a rolling boil 
     The SG stayed abou the same for the last 30 mins so I ended the charging . 
     Seems low to me. 
     I’m charging the second lowest battery now checking every 30 mins 
      This is not going the way I  expected  , Normally I put 2 6v batteries together and charge at 12 volt . 
       215 ah at 12 volt .
     The charger kicks in at 40 amps and drops down to 22 amps in 10/15 minutes . 
     As the battery charges the amps drop and the volts increase . 
     I would stop charging around 15.4  15.6 volts the battery’s would be warm but not hot . 
     The SG would be above 12 75 and I would stop charging . 
     At this point I think I would be ready for EQ charge. 
     I don’t know why the 6 v battery buy it self is acting different ?
  • EstragonEstragon Posts: 2,453Registered Users ✭✭✭✭
    If you have 2 6v battieries close in SG to each other, you can charge/EQ in series at 12v if you want and/or have better 12v charging equipment. The main reason to charge individually at 6v, IMHO, would be to avoid overcharging a good battery to recover a bad one. If they're both in about the same state though, it should be ok.
    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 just have 2 car chargers and one heavy 30amp charger .
     I’ve never really had to do any  serious charging . 
     I charged the next battery for 2 hours and it did not  budge off 1265 SG charged for a extra 30 min with no movement so I stoped charging. 
     Charging my best battery of the bunch now SG 1265 volts 3.3 volts 
  • wellbuiltwellbuilt Posts: 267Solar Expert ✭✭✭
     Well basically I wound up just charging All 8 battery’s for 2 hrs to bring up the voltage. 
     They are sitting at 6  3.9    6 40 volts , the SG has  equaled out between cells but none of the cells have come up to 
      1275 SG  most sells are around 12. 65 ? And the  hydrometer  is very sluggish . 
      The water seems to be at the   Correct height ? I do have one battery I’m charging it now That was reading bad on my smart charger . ( don’t know how smart the charger is ) 

       Could the battery be made to give good service at 1265 SG 
    .
     is the 1265 a good reading for new battery’s? 
         
        Should I just bring them back and start over ? 
      Seek out a better battery ? 
          What do you guys think .
        
     
        
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