gel batteries....equalize charge or not?

gpigeongpigeon Posts: 22Registered Users ✭✭✭
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. Posts: 28,137Super Moderators, Administrators 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
  • gpigeongpigeon Posts: 22Registered Users ✭✭✭
    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 KurthMarc Kurth Posts: 448Solar Expert ✭✭✭✭
    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.
  • PhotowhitPhotowhit Posts: 4,764Solar Expert ✭✭✭✭
    @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, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • BB.BB. Posts: 28,137Super Moderators, Administrators 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
  • mcgivormcgivor Posts: 2,391Solar Expert ✭✭✭✭✭
    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 bank 
    900W  3 × 300W No name brand Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal as a backup system. 
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergencies and welding.
  • gpigeongpigeon Posts: 22Registered Users ✭✭✭
    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.

  • PhotowhitPhotowhit Posts: 4,764Solar Expert ✭✭✭✭
    edited March 28 #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, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • mcgivormcgivor Posts: 2,391Solar Expert ✭✭✭✭✭
    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 bank 
    900W  3 × 300W No name brand Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah FLA 24V nominal as a backup system. 
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergencies and welding.
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