Equalizing Batteries Current drops off.

pechan
pechan Solar Expert Posts: 92 ✭✭
in Off Grid Solar & Battery Systems #1
I have a question about equalizing my VRLA Absolyte batteries.

I have removed the caps and added about 8 oz of distilled water.

I have my classic charge controllers set to equalize @ 61 volts (48 Volt System)
The capacity of my bank is 4000 amp hours.

I want to do a 6 hour equalizing cycle but shortly after beginning the equalizing cycle the Classic chargers stop charging the bank and show 0 watts/ 0 amps/ 61 volts.

I also have my outback radian inverters charging the bank off of a 5 kw generator. It is sending 3-4 kw into the batteries ( depending on the house loads).

My question is is it normal that the classic controllers are not charging the bank? I did do a full charge on the bank before starting the equalizing cycle.

Should I discharge the batteries 20% then restart the cycle?

Im thinking that the classics are reading a slightly higher voltage therefore are turning off?
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Comments

  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #2
    Re: Equalizing Batteries Current drops off.

    It does sound like the Charge Controllers are cutting themselves back because of the generators input. You mentioned 6 hrs as your Equalize time. Generally your EQ is based on the SG level ( Specific Gravity ) you are trying to reach based on the electrolyte fill strength. To do that you need a hydrometer and check the SG level every hour. The problem with using set number of hours is that you never know if it will take a hour or 16 hours, by using set time it's a shot in the dark.

    You also need to watch the temperature of the batteries and keep them below 110° -115° F.
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  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #3
    Re: Equalizing Batteries Current drops off.

    61 volts sounds very high for equalizing VRLA batteries.

    I did a quick search and found a suggested 2.35 volts per cell here..

    Same here.

    Yes you want to have fully charged batteries before you equalize.
    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.
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #4
    Re: Equalizing Batteries Current drops off.

    I never knew of a VRLA Battery that you added water to. I looked at those two .pdf's and I don't see it mentioned.
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  • pechan
    pechan Solar Expert Posts: 92 ✭✭
    #5
    Re: Equalizing Batteries Current drops off.

    Thanks for the responses so far.
    I am doing a light duty version of the restore process outlined in this thread: http://forum.solar-electric.com/showthread.php?4624-Low-rest-voltage-on-GNB-absolyte-IIP-cells

    There they take these cells up to 2.60 vpc.

    You can add water to these but you have to take off the regulating valves to do so.

    I cannot test the SG as these are AGM style of batteries, I am taking regular readings of each cells voltage and trying to get them equal, after 8 hours of equalizing they range from 2.4 to 2.6 vpc.

    I have been making sure they are not overheating, but I have little fear of that since I am only supplying 100~ amps into a 4000 amp hour bank.
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #6
    Re: Equalizing Batteries Current drops off.
    pechan wrote: »
    Thanks for the responses so far.
    I am doing a light duty version of the restore process outlined in this thread: http://forum.solar-electric.com/showthread.php?4624-Low-rest-voltage-on-GNB-absolyte-IIP-cells

    There they take these cells up to 2.60 vpc.

    You can add water to these but you have to take off the regulating valves to do so.

    I cannot test the SG as these are AGM style of batteries, I am taking regular readings of each cells voltage and trying to get them equal, after 8 hours of equalizing they range from 2.4 to 2.6 vpc.

    I have been making sure they are not overheating, but I have little fear of that since I am only supplying 100~ amps into a 4000 amp hour bank.
    I guess that was my point, I gave you the standard that FLA batteries use for a EQ. I read your first line, but was trying to figure what you were trying to achieve. I am not sure that trying to re-hydrate them is going to work. Are the plates sleeved ??
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  • pechan
    pechan Solar Expert Posts: 92 ✭✭
    #7
    Re: Equalizing Batteries Current drops off.

    What do you mean by sleeved? I looked inside the batteries and there is like white felt between the plates and the plates are about 1/4" thick.
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  • Blackcherry04
    Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    #8
    Re: Equalizing Batteries Current drops off.
    pechan wrote: »
    What do you mean by sleeved? I looked inside the batteries and there is like white felt between the plates and the plates are about 1/4" thick.
    Not being familiar with their construction, some of them have the electrolyte contained in sleeves / envelopes and not pooled or free in the outer container.
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  • pechan
    pechan Solar Expert Posts: 92 ✭✭
    #9
    Re: Equalizing Batteries Current drops off.

    These are more like sheets of felt in between the plates, you can see the tops of the plates if you pull the valve out.
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  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    #10
    Re: Equalizing Batteries Current drops off.

    FYI, the optimal orientation for Absolyte cells is horizontal, in vertical you get about 75% capacity out of them. This info from a local rep.
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
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  • pechan
    pechan Solar Expert Posts: 92 ✭✭
    #11
    Re: Equalizing Batteries Current drops off.
    westbranch wrote: »
    FYI, the optimal orientation for Absolyte cells is horizontal, in vertical you get about 75% capacity out of them. This info from a local rep.

    Thanks West, I have them in the original steel racks in the horizontal position.
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