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  • #16
    Originally posted by dorff View Post
    if i do the full charge with the dumb charger it does get a little over 15v, but I've never let is run till amperage goes to zero.

    the xantrex I can set both bulk/absorption & float modes to 15v, but i think it will stop charging once it thinks voltage is high enough.

    so I guess I'll use the dumb charger and just wait until amperage going into the battery gets close to zero.
    First make sure water level is OK. Then charge to 14.5 volts until current stops, rest, then EQ.

    Use whatever charger you want. Ideally you want one that charges at C/10 or as close as you can get it. Below C/12 and it takes too long and will not gas the batteries. Crowns are pretty good and can handle up to a C/6 with no issue.

    What I am driving at is charge as fast as you can so you are not doing this for 2 or more days. C/10 to C/6 is good. Just note the EQ could take up to 24 hours. So make sure you do a regular full charge first. That should cut the time down by half or more on EQ.
    Last edited by Sunking; 07-24-2017, 03:44 PM.
    MSEE, PE

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    • #17
      after the full charge rested overnight voltage was 13.1, SG was 1275.

      started the EQ charge but i can't get either the dumb charger or the xantrex to throw enough amps at 15.5v to get things boiling, I'm only able to get 1.3 amps pumped into it.

      That is giving me 2-3 bubbles every second, certainly not a rolling boil. absolutely no increase in battery temp

      bumped voltage to 16.5 just to see what happens, amps increase to almost 3, and the bubbling does get more active.

      i'll leave it 15.5 v and see what happens over a couple of hours.

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      • #18
        Originally posted by dorff View Post
        started the EQ charge but i can't get either the dumb charger or the xantrex to throw enough amps at 15.5v to get things boiling, I'm only able to get 1.3 amps pumped into it.
        It is not the Charger that controls current, it is battery internal resistance and battery open circuit voltage. I should say the Charger only limits maximum charge current. What you are seeing is normal. If you are seeing 1.275 on all cells, you are equalized. Give it an hour and if you do not see any more rise, you are done.
        MSEE, PE

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        • #19
          well Sunking I did the EQ charge at 15.5v, let it rest overnight, the voltage was good, SG good, yet with a 3 amp draw i got even fewer amp hours out of the battery. Got only 3.5 amp hrs before the voltage fell to 11V. While the batteries did bubble during EQ, nothing dramatic, its temperature never moved above room temperature.

          last night i came across this point of view

          http://batteryuniversity.com/learn/a..._to_prevent_it

          they recommend 15-16v charge for 24 hours to accomplish the higher internal battery temperature to potentially correct any soft sulfation.

          And if this doesn't work then they imply that some might be fixed after weeks of a low voltage charge.

          do you think this might be worth a try?

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          • #20
            Originally posted by dorff View Post
            well Sunking I did the EQ charge at 15.5v, let it rest overnight, the voltage was good, SG good, yet with a 3 amp draw i got even fewer amp hours out of the battery. Got only 3.5 amp hrs before the voltage fell to 11V. While the batteries did bubble during EQ, nothing dramatic, its temperature never moved above room temperature.

            last night i came across this point of view

            http://batteryuniversity.com/learn/a..._to_prevent_it

            they recommend 15-16v charge for 24 hours to accomplish the higher internal battery temperature to potentially correct any soft sulfation.

            And if this doesn't work then they imply that some might be fixed after weeks of a low voltage charge.

            do you think this might be worth a try?
            may be battery has internal leak and it got self discharged overnight? Did you check SG in the morning before discharging it and confirm it was even and the same as at the end of EQ? How SG looks after discharge?

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            • #21
              If all the sulfur is in solution as acid (correct SG) then there is NO sulfur on/in the plates (or not enough to matter)
              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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              • #22
                Originally posted by dorff View Post
                well Sunking I did the EQ charge at 15.5v, let it rest overnight, the voltage was good, SG good, yet with a 3 amp draw i got even fewer amp hours out of the battery. Got only 3.5 amp hrs before the voltage fell to 11V. While the batteries did bubble during EQ, nothing dramatic, its temperature never moved above room temperature.

                last night i came across this point of view

                http://batteryuniversity.com/learn/a..._to_prevent_it

                they recommend 15-16v charge for 24 hours to accomplish the higher internal battery temperature to potentially correct any soft sulfation.

                And if this doesn't work then they imply that some might be fixed after weeks of a low voltage charge.

                do you think this might be worth a try?
                I know the article well. That is why I always say solar is piss poor and will destroy any battery. It takes 12 to 16 hours to fully saturate a battery. Solar cannot do that. Just the way it is and the nature of the beast. That is why one must have a generator is off grid so you can fully charge your batteries once a week.

                Anyway you have already applies an Over Charge of 15 to 16 volts. Read the article again, you have Hard Sulfation which is not reversible. How do I know? Because you told me without knowing it. Your voltage is not stable during discharge, it falls quickly with a load. Read the article, it tells you that.

                At this point you have nothing to loose, charge at high of a voltage as you can, 16, 17, 18 whatever. It will not hurt a dead battery. Like kicking a dead horse, the horse will not mind if you kick the crap out it.

                Time for a Warranty claim.

                EDIT NOTE:

                Wait a minute, Hold The Bus. Where are you measuring the battery voltage while discharging?

                If you say anywhere else but the Battery Term Post is the WRONG ANSWER.

                If you are measuring at the load or Inverrter terminals is the wrong place. If that is what you are doing I bet if you measured on the Battery Term post the voltage will be fine. If that is the case is telling your wiring skills suk. Keep the load applied until the battery voltage reaches 10.5 volts.
                Last edited by Sunking; 07-26-2017, 06:25 PM.
                MSEE, PE

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                • #23
                  at a 3.8 amp load (measured with clamp meter between battery and inverter) (120v fan plugged into xantrex inverter, inverter says its delivering 2.6amps) the battery runs for about 1.75 hours before voltage falls below 11.0v. The voltage does a very slow fall from 12.7 to 12.0 and then in the last 10 minutes it quickly falls to 11v.

                  I measure the voltage at the battery term posts.

                  I even thought my SG gauge was messed up so I got another one, and it reads the same as the other one. SG never moves, it's at 12.75 at the end of charge, at end of rest and at end of load when the voltage is at 11v. It reads 12.75 all the time.

                  After the xantrex cuts out the inverter due to low voltage, give the battery 5-10 minutes and voltage at the terminals are back to 12.5+

                  As someone said, how can the issue be sulfation if the SG is always at 12.75?

                  So I'm guessing the comment by a guy I called at a Interstate battery store (he was easy to reach), about the batteries just being defective with something wrong with them that is creating high internal resistance after the top 15% of the batteries usable capacity is used, might be right.

                  file a warranty claim.... haha...thats a good one Sunking - i guess it's worth a try.......

                  These 2 dud batteries I pulled from my new 5th wheel and dropped in 2- US Battery L16's - US L16HC XC2, so I now have 420 amp hours at 12 volts. My charger is built into the power center of the 5th wheel, a Progressive Dynamics PD4575, which has a 4 stage 75 amp charger built into it -
                  • BOOST Mode 14.4 Volts - Rapidly brings RV battery up to 90% of full charge. LIMITED TO 4 HOURS
                  • NORMAL Mode 13.6 Volts - Safely completes the charge.
                  • STORAGE Mode 13.2 Volts - Maintains charge with minimal gassing or water loss.
                  • EQUALIZATION Mode 14.4 Volts - Every 21 hours for a period of 15 minutes prevents battery stratification
                    & sulfation - the leading cause of battery failure.
                  Am I good with this or do I need use something else. None of its voltage or time parameters are customizable.

                  I've had some issues with these batteries not being back to a full charge the next morning after being on the charger for 18 hours, and the only thing they were running the day before while on the road was a 1000w magnum inverter to power the residential refrigerator.

                  Do these new L16's also require an initial EQ charge to get them started on the right path.






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