High Specific Gravity Unexplained

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Comments

  • VicVic Posts: 2,897Solar Expert ✭✭✭✭

    Hi Ako,

    Your idea of waiting a few days with the present settings,   so see how the bank responds sounds fine to me.

    Will have a couple of questions about the data that you posted,   but later for that.   Yes,   this is a long Thread,   and there have been many,   many suggestions  of what you should try.   This can be a bit overwhelming,   but you have hung in there.    Later,   Thanks for your Spain location.     Vic

    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • AkoAko Posts: 89Registered Users ✭✭
    edited July 11 #63
    Well Ive done what Rolls suggested and not had much effect other than reduce the SG slightly and seeing the voltage back to 25.3 when entering night mode rather then the 25.6-25.8 im used to seeing since the SGs increased but i still have a long way to go to be at safe SG levels so im now wondering if my batteries have been irreparable damaged . Unfortunately i dont use enough power during the non charging times for the voltage to go low enough to disconnect which was the reason for replacing my 10 year old Tudor batteries of the same size , my voltage just before charging begins is between 24.1-24.6 , slightly lower than before this problem started , previously i was showing close to 25v  , my amps coming in during the charging period has not declined , if anything its increased slightly to average closer to the upper limit of my systems historical records at this time of year .

    I followed Rolls advisers instructions and have dropped my voltage from the originally advised 29.76 ( .24 less than the manual still states ) down to 29.16 , a reduction of .6v together with reducing the Absorption time from 5 hours to 2 ,( the minimum time recommended ) . Also did an Equalisation a few days ago . The only thing i have not done is add distilled water , the batteries are all bubbling away nicely daily during charge but the levels have only dropped slightly and still within the upper and lower levels shown in the Rolls manual , between 6mm and 13mm . The batteries are going into float now each day for several hours .

    I have again read the manual for the TS60 and can see theres the option to change from PWM to ON/OFF switching , will this help ?
    1050 Watt 24v Array . BP and Atersa 72 cell Panels 
    Morningstar TS-60 Charge Controler
    4 x 6v 605 Apm/Hr Rolls S-605 Batteries
    Solener 1500w Pure Sinewave Inverter
    Studer 400 Watt Pure Sinewave Inverter
  • AkoAko Posts: 89Registered Users ✭✭
    edited July 11 #64
    Think might have found a possible causes so i have today changed the TS60 and this whats become obvious .

    The voltage readings on the Batteries , TS60 battery input connectors show a voltage higher than the battery terminals 0.1-.02 but im not sure if that might have something to do with the terminals being inside the TS60 and partly reading the solar input also , some sort of slight drain back ?

    The sense wires inside the TS60 show a voltage of 0.1-0.2v lower than the battery terminals , that would explain overcharging but unfortunately it wasn't possible to disconnect the batteries or but i wouldent have thought it would make a difference for the purpose of seeing a difference in voltages as put raising or lowering voltages through input or load would be uniform across either reading sources although i did reduce the output voltage to 60 watts . I understood a sense wire was to compensate for loss through cables between batteries and TS60 so should be higher , having said that i have only a maximum of 1 metre of cable between the Batteries Bus Bar and TS60 using 6 gauge copper multi strand cable so i wouldent have expected much of a loss anyway . I used the same multi meter for all readings .




    .


    1050 Watt 24v Array . BP and Atersa 72 cell Panels 
    Morningstar TS-60 Charge Controler
    4 x 6v 605 Apm/Hr Rolls S-605 Batteries
    Solener 1500w Pure Sinewave Inverter
    Studer 400 Watt Pure Sinewave Inverter
  • jonrjonr Posts: 991Solar Expert ✭✭✭✭
    edited July 11 #65
    No meter is going to read "equivalent steady state voltage" with a pulsed/PWM DC supply and a non linear load like a battery.   Roll's specs are steady state voltages.  See here for the nonsense you get from even good meters:

    https://meettechniek.info/multimeter-avo/measurement-deviation.html


    IMO, Roll's advice is bad (for your situation) or misunderstood - I would just accept your high SG readings and not undercharge to reduce it.   Why - because if you haven't reduced fill level or added acid, then the high SG reading can't represent the actual acid concentration (which is what really matters).
  • AkoAko Posts: 89Registered Users ✭✭
    I used a digital Multi meter Jonr  so is it possible the difference between the readings on the TS60 and the Multi meter will be different but i was mainly concerned with the differences between Batteries , TS60 battery connectors inside the unit and the sense wire connectors inside the unit rather then what they actually were .

    Dont think accepting the higher SGs would be good , Rolls themselves told me that they were bad for the batteries and from what i have read online everything else supports that and anyway , they were normal for at least a year and as far as i can tell nothing else has changed to explaine it other than the battery temperatures are 10 degrees C higher .
    1050 Watt 24v Array . BP and Atersa 72 cell Panels 
    Morningstar TS-60 Charge Controler
    4 x 6v 605 Apm/Hr Rolls S-605 Batteries
    Solener 1500w Pure Sinewave Inverter
    Studer 400 Watt Pure Sinewave Inverter
  • jonrjonr Posts: 991Solar Expert ✭✭✭✭
    My guess: your sense wire circuit has some resistance, capacitance and inductance.    This will change the pulsed DC waveform shape and the meter reading.
  • AkoAko Posts: 89Registered Users ✭✭
    edited July 11 #68
    I have now bitten the bullet and removed the sense wire on the TS60 end, i cant see it was needed anyway as i didnt see a voltage drop between batteries and TS60 internal connectors , the only drop in voltage i see is between the batteries and the TS60 internal sense connector when it was conected where  im sure i should be seeing an equal voltage . . As i see it the worst case scenario is without a sense wire undercharging is a possibility but in this case i think its possible the sense wire could actually have been causing an overcharge as its giving a lower voltage then Batteries .

    My sense wire was the right gauge and no more than a meter long and im sure when i first connected it the readings were the same as the battery as it is now that its no longer conected at the TS60 end .After disconnecting the sense wire i left it connected to the battery and read the voltage with a multi meter and it was showing exactly the same on both so even if it was working correctly it wasn't needed .

    Problem with the MSview is when yo disconnect the TS60 you dont have any readings for the previous 24 hours , its gobbledegook . I have been trusting MSview to give me accurate readings as its those im using for everything as i dont have a meter connected  .

    Will have a better idea of the effect is had in 24 hours .
    1050 Watt 24v Array . BP and Atersa 72 cell Panels 
    Morningstar TS-60 Charge Controler
    4 x 6v 605 Apm/Hr Rolls S-605 Batteries
    Solener 1500w Pure Sinewave Inverter
    Studer 400 Watt Pure Sinewave Inverter
  • mcgivormcgivor Posts: 1,878Solar Expert ✭✭✭✭
    edited July 12 #69
    The voltage sense will compensate for voltage drop when under load, the higher the charge current the higher the volt drop, in reality as the current drops to minimal amounts, the voltage difference at battery and CC would be less, disconnected it would have a minimal effect on overall charging.

    The process of elimination requires the change or removal of one component or setting if no change is observed then replace/restore before moving on to the next. Changing multiple things could result in other problems without revealing the root cause. The pragmatic approach would be to think along the lines of why the SG is higher than it should be, the only way it could rise would be through water loss or addition of acid, no amount of overcharging can increase the amount of acid in solution therfore it must be related to concentration meaning not enough water.
    Lowering the charge voltage may eventually reduce SG but will be at the expense of lost capacity due to sulfation.

    Just a collection of thoughts, 

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

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