gel batteries....equalize charge or not?

gpigeon
gpigeon Registered Users Posts: 34 ✭✭✭
I have had 24x Exide Energystore 2RPG1410 batteries plus a SchneiderXW8548 inverter plus 2x 80/600 charge controllers installed for about 8 months now and am generally quite happy with the overall performance. The deepest disch. has been this morning and that is 125Ah from a total of 1410Ah, so that is only down to about 92% SOC.
However there seems to be some controversy over whether to "boost" and "equalize" charge the batteries.
Exide, the battery suppliers say YES...equalize for 2 hrs each month....the Schneider people say NO...do no equalize.
Have any other forum members got Gel batteries? if so, how do you monitor their condition and do you equalize charge them?
Other comments???
Thanks.
Bill W.

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Do they give you a rate of charge?

    In the USA, most gel batteries are rated for a maximum 5% rate of charge.

    If you charge too fast or too high of voltage, the plates gas and make permanent bubbles in the gel electrolyte. Which permanently reduces battery capacity.

    Many European gel batteries appear to not have the 5% limitation.

    Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • gpigeon
    gpigeon Registered Users Posts: 34 ✭✭✭
    Hi Bill,
    It looks as if the "GNB - Sonnerschein" spec sheet states 20%C10....which works out to 1085/5 = 217A. But, I think Schneider gave me a figure of 108A (ie 10%C10) Either way, much different to what you are saying. I believe the highest charge rate I have actually witnessed is around 60A. The system has a 9.6kW PV array.
  • Marc Kurth
    Marc Kurth Solar Expert Posts: 1,142 ✭✭✭✭
    Addressing your question about equalizing:
    - Go with the battery manufacturers recommendation, but have them define the precise method and time.

    - Current should not be an issue because EQ is performed after the battery bank has reached full charge, which is when it inherently draws low current.

    Marc
    I always have more questions than answers. That's the nature of life.
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    @gpigeon Marc sells a lot of batteries, likely the best advice you could find around here.
    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.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    You also need to ensure that you understand the charging state/voltage set points too... Most "industrial" batteries have a very specific charging algorithm which solar cannot match at all...

    Typically for AGM and GEL, "Equalize" is just an extended "absorb stage" charging (not elevated charging voltages--Although, Concorde Lifeline batteries do have a "recovery" charging that is much different than any other battery equalization scheme).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Equalization is generally not used with AGM or GEL, it is usually a slightly higher voltage, or boost which is applied after a significant deep discharge, or when a cell or cells lag the voltage of the ballance of cells. Usually this voltage is in the neighborhood of 2.4V per cell, which is not significant when compared to flooded cells, however performing a boost charge unnecessarily would probably be more harmful than not doing it at all. If the depth of discharge is low and cell voltages are equal, it would be better to follow the regular charging regime. As @BB mentioned, industrial batteries are usually grid charged, read the special considerations for solar charging in the instruction manual, currents may have to be higher due to the linited window of opportunity.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • gpigeon
    gpigeon Registered Users Posts: 34 ✭✭✭
    Thank you gents for your input....
    Mcgivor.....I note that you also have "Schneider" gear. For how long and how have you found it? Satisfactory? Is Schneider very popular is the US?
    I have a second 10kW PV system which is grid tied but has SMA inverters. That has been operating for about 7 yrs without any problems and seems to be much simpler in it's settings than the Schneider setup. Perhaps the Schneider gear is too sophisticated for my level of use.
    Rgds.
    BillW.

  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    edited March 2018 #9
    gpigeon said:
    PV system which is grid tied but has SMA inverters...   ....and seems to be much simpler in it's settings than the Schneider setup. Perhaps the Schneider gear is too sophisticated ....
    Off grid battery based system are much more complex than Grid tied systems, with more information, perhaps we can help.
    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.
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    gpigeon said:
    Thank you gents for your input....
    Mcgivor.....I note that you also have "Schneider" gear. For how long and how have you found it? Satisfactory? Is Schneider very popular is the US?
    I have a second 10kW PV system which is grid tied but has SMA inverters. That has been operating for about 7 yrs without any problems and seems to be much simpler in it's settings than the Schneider setup. Perhaps the Schneider gear is too sophisticated for my level of use.
    Rgds.
    BillW.

    To answer your question, basically I needed a MPPT controller, wanted Morningstar but the vendor in Thailand had a minimum order of 2 units, so Schneider 150-60 was not only less expensive but comes with an LCD display, for what it's worth. Shortly after the purchase, lightning took out my Cotek inverter, a cheap inverter filled the gap until a replacement could be sourced. Being that I already had a Schneider controller it only made sence to get a Schneider inverter/charger. Basically I built a complete new system, batteries and all, and to be honest the inverter exceeded my expectations, based on generic components, reference to inverters that is, there is so much it is capable of including grid and or generator support, load shaving etc. etc. , which simple inverters pale in comparison and the price is competitive. In short I'm more than satisfied, it literally opened my eyes to what professional equipment is, the XW series is one step up, so my thoughts  would be that it would that it would be even better, in terms of options. Schneider is a global company who aquired the solar division front Xantrex, some call the charge  controller a dumb box,  lacking in features offered by other manufacturers, perhaps so, but it gets the job done. Making the move to more serious equipment, is not something I regret, SMA is of the same class, from what I understand,, as far as popularity  in the US is concerned , I've no idea, but from hands on experience, they are probably underrated, from what I've observed.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • gpigeon
    gpigeon Registered Users Posts: 34 ✭✭✭
    So, the inevitable has occurred!!!! I have had one of the 24 cells fail. It charges up ok during the day but drops to zero V through the night. The battery supplier suggested that I remove that bad cell and change the charger/inverter settings to suit a "46V" battery. This I have done and the system seems to be working ok, naturally at 4% less capacity.
    I have returned the bad cell to the supplier for "testing/rejuvenation" but I doubt that they will provide any warranty because the battery has NEVER been equalized and it has been in service for 4 yrs. (5 yr warranty????). To add to the problem, that type of cell is no longer available so I cannot just add a new one. Not that is a good idea anyway???
    The title of this post is "to equalize or not"? Well, I am just the man in the middle! The battery suppliers say to equalize....Schneider and most folk on the forums say NOT to equalize.
    It will be interesting to see what the battery people (GNB/ Exide) have to say.
    Any ideas, comments, suggestions???
    Thanks.
  • Marc Kurth
    Marc Kurth Solar Expert Posts: 1,142 ✭✭✭✭
    Three years ago, you said: "Exide, the battery suppliers say YES...equalize for 2 hrs each month" but you chose not to follow the manufacturer's instructions - and now you have a premature battery failure. Am I reading the situation accurately? 
    I always have more questions than answers. That's the nature of life.
  • gpigeon
    gpigeon Registered Users Posts: 34 ✭✭✭
    Three years ago, you said: "Exide, the battery suppliers say YES...equalize for 2 hrs each month" but you chose not to follow the manufacturer's instructions - and now you have a premature battery failure. Am I reading the situation accurately? 

    Hi Marc....yes, you are reading the situation correctly! Exide said to equalize....Schneider said not to equalize because their charge controller is not capable doing the job correctly! Keep in mind that I did not personally choose either the batteries or the charger....I left that to the "experts"!
    Why on earth don't these 2 German companies get together and work out a system that suits. One would think we are dealing with 3rd world countries!!!!

  • Marc Kurth
    Marc Kurth Solar Expert Posts: 1,142 ✭✭✭✭
    Ah, I did not make the connection of "doing the equalize correctly."  I would have thought that the Schneider system would be able to do anything that needs doing.
    I always have more questions than answers. That's the nature of life.
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Schneider controllers have a one hour EQ maximum which may be too short as Exide recomends two, manual EQ is probably possible but auto is not, which may be why they couldn't meet the criteria.

    FYI.  Schneider by the way is a French conglomerate which operates Xantrex as a subsidiary, Exide is a US company  which  acquired GNB, so neither are German.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • gpigeon
    gpigeon Registered Users Posts: 34 ✭✭✭
    mcgivor said:
    Schneider controllers have a one hour EQ maximum which may be too short as Exide recomends two, manual EQ is probably possible but auto is not, which may be why they couldn't meet the criteria.

    FYI.  Schneider by the way is a French conglomerate which operates Xantrex as a subsidiary, Exide is a US company  which  acquired GNB, so neither are German.
    "mcgivor", thanks for your reply.....where exactly did you see that "exide recommends two" ????

    Oh. you may be correct about the  "French connection"...I was just going by the name "Schneider". Sounded German. The batteries are actually labelled "GNB, a division of Exide Technologies" as well as "Sonnenschein' made in Germany", so who knows?????

    Marc, I like your little saying..."I always have more questions than answers...."  I am a little like that as well!
     There is another one..."Ask a stupid question and people will think your an idiot for 5 mins. Don't ask it and you will be an idiot for the rest of your life"!

    You guys have a good day.
    Cheers.
    Bill;.
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    gpigeon said:
    mcgivor said:
    Schneider controllers have a one hour EQ maximum which may be too short as Exide recomends two, manual EQ is probably possible but auto is not, which may be why they couldn't meet the criteria.

    FYI.  Schneider by the way is a French conglomerate which operates Xantrex as a subsidiary, Exide is a US company  which  acquired GNB, so neither are German.
    "mcgivor", thanks for your reply.....where exactly did you see that "exide recommends two" ????

    Oh. you may be correct about the  "French connection"...I was just going by the name "Schneider". Sounded German. The batteries are actually labelled "GNB, a division of Exide Technologies" as well as "Sonnenschein' made in Germany", so who knows?????

    Marc, I like your little saying..."I always have more questions than answers...."  I am a little like that as well!
     There is another one..."Ask a stupid question and people will think your an idiot for 5 mins. Don't ask it and you will be an idiot for the rest of your life"!

    You guys have a good day.
    Cheers.
    Bill;.
    The 2 hours came from the manual, attached pdf , the statement is merely to offer a possible explanation, I do believe that the manual is the correct one, correct me if I'm mistaken.

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • gpigeon
    gpigeon Registered Users Posts: 34 ✭✭✭
    "Mcgivor"....I do believe that is the correct manual. At least all the batt. model nos are correct!!

    I just don't see why Schneider state that their 80/600 charge controllers can't do equalising. That Eq.V. can be set manually as can the Eq. time.
    Still all a puzzle to me.
    I have not had any report on my dead cell from GNB Exide yet.


  • gpigeon
    gpigeon Registered Users Posts: 34 ✭✭✭
    The "dead" cell has been with Exide for a couple of weeks and they tell me that is unrecoverable. They are not interested in a warranty claim because they say the Schneider gear does not charge their batteries properly and no equalization has been carried out. However, they have supplied at 25% disc. a 10EPzV800 cell which I will install tomorrow.
    What do you guys think about fitting cells of different types and capacities together? That is 23x 2RPG1410's and 1x 10EPz800?
    Thanks.
    BW
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    The other question for Exide is why did one battery fail--And the rest are running fine.

    Mixing cells of different types/capacities is always a less than ideal choice... If you where going to get some "cheap" FLA golf cart batteries and only expected the bank to run (relatively) OK for a year, you could probably sneak by.

    If you were trying to get another 3-5 years--Then I would try to, at least, match chemistry... FLA to FLA, AGM to AGM, Gel to Gel, etc...

    Matching capacity with, for example, 2x200 Amp batteries in parallel to replace a single 400 amp battery with same/similar chemistry would work "good enough" for again a year or couple year of limping along.

    The other question--How "good" are the remaining cells and what is your expectation for their life?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • gpigeon
    gpigeon Registered Users Posts: 34 ✭✭✭
    Thanks for your input Bill.
    The chemistry is the same ...ie Gel. Only the capacities are different.
    The new cell has been up and running for about a week now. It seems to be performing ok but of course it is the longevity/lifespan that counts. The mid point V variation never goes above 1.5% and is normally < than 1%.
    BUT...something interesting is happening! The V of the cell next to the new one rises to 2.6V during the Absorption stage. The V of the new cell at this stage is only 2.194V (the lowest of all)
    This seems quite high as even the recommended "equalisation" V is only 64V / 24 = 2.66V. And, it is taken to that 2.6V every day!!!!
    Exide did not know what might have caused the dead unit. The whole system is only 4 yrs old so I would have reasonably expected another 6 yrs at least from it. The batteries on average would only be discharged down to 90% SOC each day and normally be fully recharged by 10am. At a cost of $15k, the batteries are easily the most expensive part of the system. Let's hope the some new battery technology shows up in the next few years.
  • gpigeon
    gpigeon Registered Users Posts: 34 ✭✭✭
    gpigeon said:

     That is 23x 2RPG1410's and 1x 10EPz800?

    Ok, an update....so the new cell was installed about 14 months ago! Exide offered me the scrap price for the "dead" cell but I brought it home and placed it in parallel with the new 10EPzV800 using only 2.5mm2 cable. After a couple of months I noted that the "dead" cell was now holding it's voltage. Somehow it recovered itself!
    Then, about 6 months ago another of the original 2RPG1410 cells failed (would not hold it's voltage) so I replaced this second one with the now recovered one. All has been good for 6 months now!
    I have placed the second failed cell in parallel now. It also seems to have been rejuvenated! 
    What do you lot think? what is going on here?
    Thanks.