Equalizing current for Trojan L16

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706jim
706jim Solar Expert Posts: 515 ✭✭✭✭
in Off Grid Solar & Battery Systems #1
I'm aware that equalization of an L16 will require about 31 volts. That said, what current would be necessary once the battery starts bubbling?
Island cottage solar system with 2500 watts of panels, 1kw facing southeast 1.3kw facing southwest 170watt ancient Arco's facing south. All panels in parallel for a 24 volt system. Trace DR1524 MSW inverter, Outback Flexmax 80 MPPT charge controller 8 Trojan L16's. Insignia 11.5 cubic foot electric fridge. My 30th year.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,457 admin
    #2
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    Somewhere around 2.5% to 5% of the battery bank's C20 capacity should be plenty of equalization current (for flooded cell lead acid batteries)...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • 706jim
    706jim Solar Expert Posts: 515 ✭✭✭✭
    #3
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    Thanks Bill. My 35 amp inverter charger should be adequate for the task then.
    Island cottage solar system with 2500 watts of panels, 1kw facing southeast 1.3kw facing southwest 170watt ancient Arco's facing south. All panels in parallel for a 24 volt system. Trace DR1524 MSW inverter, Outback Flexmax 80 MPPT charge controller 8 Trojan L16's. Insignia 11.5 cubic foot electric fridge. My 30th year.
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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,759 ✭✭✭✭✭✭
    #4
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    And you do know that the battery must be fully charged first before EQ is attempted. A battery that will not charge normally should not have EQ unless you know what you are doing!
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

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  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    #5
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    +1
    Applying Eq voltage without current limiting to a battery which is not yet fully charged would be a really bad idea.
    SMA SB 3000, old BP panels.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,457 admin
    #6
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    Personally, as I understand "equalize"--Yes the battery is "mostly fully charged", and the equalization voltage levels is what "sets" the equalization current to ~2.5 to 5% rate of charge.

    If you hit with "equalize" voltage to a discharged battery bank, you should get a "surprisingly" high charging current (or the battery bank will simply not be at the equalize voltage set point).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Johann
    Johann Solar Expert Posts: 245 ✭✭✭
    #7
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    And for how long should equalizing be done?
    And how frequent in days or month should it be done?
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #8
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    Hi Johann,

    Speaking of Flooded batteries, in general, each battery manufacturer has specific advice on Equalization. Some say to EQ every specific time interval. Some say to EQ when the spread in SG readings is greater than a certain number of "points", etc.

    Here is a link to the Surrette Battery Manual. On pages 16 and 17, is a summary of What Surrette recommends for their Flooded batteries:
    http://rollsbattery.com/public/docs/user_manual/Rolls_Battery_Manual.pdf

    FWIW, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 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.
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  • Photowhit
    Photowhit Solar Expert Posts: 6,003 ✭✭✭✭✭
    #9
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    Awe Heck, I LOVE this one!

    Trojan doesn't recommend a maintenance equalizing in their instructions. Unless
    Trojan User Guide wrote:
    Trojan recommends equalizing only when batteries have low specific gravity, below 1.235 or
    wide ranging specific gravity, > 0.030 points between cells, after fully charging a battery.


    Yet appear to disagree with themselves with this instructional video, suggesting monthly equalizing;

    https://youtu.be/jCl5klSF4tE
    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 ✭✭✭
    #10
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    Trojan recommends equalizing only when batteries have low specific gravity, below 1.235 or
    wide ranging specific gravity, > 0.030 points between cells, after fully charging a battery.
    The biggest problem with this is that once you notice 1.235 SG level on a L16 it's doubtful that the sulfate would ever be able to be removed.
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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,759 ✭✭✭✭✭✭
    #11
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    Photowhit wrote: »
    Awe Heck, I LOVE this one!

    Trojan doesn't recommend a maintenance equalizing in their instructions. Unless

    Yet appear to disagree with themselves with this instructional video, suggesting monthly equalizing;

    https://youtu.be/jCl5klSF4tE


    They are in the business of selling batteries! Yes I also saw that! Good stuff for late night reading and insomnia.
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

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  • Dave Angelini
    Dave Angelini Solar Expert Posts: 6,759 ✭✭✭✭✭✭
    #12
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    BB. wrote: »
    Personally, as I understand "equalize"--Yes the battery is "mostly fully charged", and the equalization voltage levels is what "sets" the equalization current to ~2.5 to 5% rate of charge.

    If you hit with "equalize" voltage to a discharged battery bank, you should get a "surprisingly" high charging current (or the battery bank will simply not be at the equalize voltage set point).

    -Bill


    In a rare situation where the user is not looking at cell temperature, has a bad terminal or small cable, they could get a failure mode that escalates. It would be hard to do with a 35 amp charger but further updates from the OP shows that he could use the additional advice!
    "we go where power lines don't" Sierra Nevada mountain area
       htps://offgridsolar1.com/
    E-mail offgridsolar@sti.net

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  • Johann
    Johann Solar Expert Posts: 245 ✭✭✭
    #13
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    Vic wrote: »
    Hi Johann,

    Speaking of Flooded batteries, in general, each battery manufacturer has specific advice on Equalization. Some say to EQ every specific time interval. Some say to EQ when the spread in SG readings is greater than a certain number of "points", etc.

    Here is a link to the Surrette Battery Manual. On pages 16 and 17, is a summary of What Surrette recommends for their Flooded batteries:
    http://rollsbattery.com/public/docs/user_manual/Rolls_Battery_Manual.pdf

    FWIW, Vic

    Thank you for the link. I try to get a feeling and info about batteries and do not know anything about them.
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