quick question for Midnite Classic owners

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  • 2twisty
    2twisty Solar Expert Posts: 199 ✭✭✭
    #32
    Re: quick question for Midnite Classic owners

    OK. All the reading I have done says that I should measure SG right after the charging is complete. At 11PM, that means that I will have been discharging for quite some time already, since I usually stop putting amps in at around 6-8PM, depending.

    So your statement has be somewhat confused. How will I know what the SG should be if I don't think that the batteries are full?
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #33
    Re: quick question for Midnite Classic owners

    In general, you will want to measure the SGs just after the CC has transitioned to Float. This should tell you how the Classic charger settings are doing in fully charging the batteries.

    Float is designed to just barely keeps your batteries fully charged, but measuring SGs just after the transition to Float helps remove the uncertainty of weather the Float voltage setting is really keeping the batteries fully charged.

    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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  • 2twisty
    2twisty Solar Expert Posts: 199 ✭✭✭
    #34
    Re: quick question for Midnite Classic owners

    OK. Got it. I'll start measuring SG soon. Since I already have the task of moving my panels on the 1st of the month, I think I'll put the SG monitoring to the 15th. I'll set up a spreadsheet and start tracking the SG.

    Are there any good digital hydrometers out there or ones that automatically correct for temperature? The one I have (to me, at least) seems cheap and flimsy and the markings are not terribly readable.
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #35
    Re: quick question for Midnite Classic owners

    Too-twisty,

    First, there are Refractometers, that some find easy to use ... I have no experience with them.

    Here is the Hydrovolt Hydrometer. Made in Germany, is is being distributed by MidNite Solar in NA:

    http://www.midnitesolar.com/pdfs/Hyvolt-e.pdf

    This Hydro is not widely distributed, but, at least for a while, MidNite Solar was selling them directly to end-users.

    An Auto Parts store glass Hydrometer will do for now -- buy two or three, and check them against each other, if one breaks, you have an instant spare with known characteristics. Always rinse your Hydro with Distilled Water several times, after each measuring session.

    IMO, you really MUST take initial SG readings of EACH cell of your battery bank. It is very important to make sure that your charge settings are close, or better for your expensive batteries. Simply gotta do it NOW. One disadvantage of having SO MANY batteries is the perceived tedium of measuring each cell of the bank fairly often. Once that you are confident that your charge settings are good, you can choose to only measure the SG of a few Pilot Cells -- often the cells with the lowest SG. These will allow you to quickly take a snap-shot of how your bank is doing, without spending too much time at it. But, measure each cell NOW, and this will help you start off getting the batteries fully charged, before the short days of Winter set in. Maintenance of Flooded batteries is no big deal, but please get off on the right foot, especially with any battery bank with more than a single string.

    Just my STRONG opinions. 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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  • 2twisty
    2twisty Solar Expert Posts: 199 ✭✭✭
    #36
    Re: quick question for Midnite Classic owners

    OK. The soonest I can get a better hydrometer at an auto parts store is Tuesday. I'll pick up a couple and get some measurements.

    I've also read that I should adjust water levels and then do an EQ before measuring SG. What's the consensus here? Could you walk me through your procedure?
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,590 admin
    #37
    Re: quick question for Midnite Classic owners

    Lead Acid Battery plates (and cells) are killed if the plates are exposed to air--Never let them become uncovered.

    When you "equalize" a battery, there is gas generated (hydrogen and oxygen) and heat too. The gas tends to raise electrolyte levels, and so does water expansion as the battery gets hot.

    In general, don't fill the cells too much (1/2 full is probably more than enough--to the bottom of the split ring, or whatever method your batteries use to indicate "full"--before beginning equalization)--Especially just before equalization--Over filling is a mess. You lose sulfuric acid+water and get acid around the battery box and cables. So--if the plates are covered, don't add any more water until equalization is done--Then check/add water.

    Don't add sulfuric acid to cells--Just water.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • CDN_VT
    CDN_VT Solar Expert Posts: 492 ✭✭✭
    #38
    Re: quick question for Midnite Classic owners
    BB. wrote: »
    Especially just before equalization--Over filling is a mess. You lose sulfuric acid+water and get acid around the battery box and cables. So--if the plates are covered, don't add any more water until equalization is done--Then check/add water.

    Don't add sulfuric acid to cells--Just water.

    -Bill

    OR !! if they are liquid level full and are in overflowing , siphon off the H2S04 , into it's clean container for that cell or battery . I did this and had 12 L or 3 usg of acid & water (electrolyte H2S04 ) in jugs that I used to top up the cells . My 2v cells are 1800 ah per. huge & they were abused & way under charged. Im now back to nothing left from the siphon and will only add pure distillate water . these cells are starting to come back. after a few more months , I'll see if I got them for free or I wasted 6 months time . Core weight pays well also.

    Tonns of cells to revamp .
    VT
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