Battery charging

mountainman
mountainman Registered Users Posts: 439 ✭✭
in Caravan, Recreational Vehicle, and Marine Power Systems #1
If in full sun absorb set at 14.8 volts.
after 2 hours showing 1℅ 4 amps on 400 ah Batteries. Why would S.G be 1.250?
2kw array 6 345 q cells  make sky blue 60 cc
 6 230ah GC @36 volts 
18 amp accusense charger. 3650 champion 
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  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #2
    What is the fill SG from the manufacturer? Some use lower SG to extend lifespan at the expense of slightly lower capacity.
    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.
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  • mountainman
    mountainman Registered Users Posts: 439 ✭✭
    #3
    Us battery states 1.270 minimum S.G.
    2kw array 6 345 q cells  make sky blue 60 cc
     6 230ah GC @36 volts 
    18 amp accusense charger. 3650 champion 
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  • mountainman
    mountainman Registered Users Posts: 439 ✭✭
    #4
    Batteries are not using any water. Maybe I should try raising voltage?
    2kw array 6 345 q cells  make sky blue 60 cc
     6 230ah GC @36 volts 
    18 amp accusense charger. 3650 champion 
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  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #5
    Are you using temperature compensation and are the batteries cold?
    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.
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  • mountainman
    mountainman Registered Users Posts: 439 ✭✭
    #6
    Yes I have temp compensation. Batteries are out side. Temps lately have been 35- 40 f at night. 60 f days. Daily useage ~15℅
    2kw array 6 345 q cells  make sky blue 60 cc
     6 230ah GC @36 volts 
    18 amp accusense charger. 3650 champion 
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  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    #7
    Have you checked voltage in absorb at the battery?  At ~50°F, it should be higher than the 14.8v setting.

    Also, have you measured SG at 1.27 with this meter on these batteries previously?  My first meter measured consistently low.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
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  • mountainman
    mountainman Registered Users Posts: 439 ✭✭
    #8
    If I'm away for a sunny weekend not running the inverter. SG goes up to 1.27.
     checking  the absorb  voltage on a 40f day 
    ~14.9.
    2kw array 6 345 q cells  make sky blue 60 cc
     6 230ah GC @36 volts 
    18 amp accusense charger. 3650 champion 
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  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    #9
    Assuming that's 14.9 at the battery, sounds about right.  If it's at the controller, I'd check at the battery as well.

    Are the batteries sort of fizzing a bit with a few "burps" near the end of absorb?
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
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  • mountainman
    mountainman Registered Users Posts: 439 ✭✭
    #10
    Yes on the battery. Ive looked inside the batteries and they are fizzing and occasionally they will burb. The part that puzzles me is not using water. I bought them July 1 of this year. In the summer daily  SG was good unless of course it was over cast.
    2kw array 6 345 q cells  make sky blue 60 cc
     6 230ah GC @36 volts 
    18 amp accusense charger. 3650 champion 
    · Share on Twitter
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    #11
    My L16s hardly used any water at first.  IIRC, well under a gallon in the first 6mos.  At 5yrs, they're up to ~2-3gals/season.

    If they're bubbling, I wouldn't increase voltage.  Assuming the 1% / 4a read was net into the bank (ie not reduced by loads), I don't know why SG would be that low.

    Are the cells consistently 1.25? 

    Could the meter be sticking?  Sometimes a bit of crud finds its way in, requiring pretty vigorous rinsing to clear.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
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  • mountainman
    mountainman Registered Users Posts: 439 ✭✭
    #12
    Yes end absorb 4 amps 400 ah Batteries with no loads.
    Like I said if Im away a couple days not using any power.
    SG comes back to 1.270
    2kw array 6 345 q cells  make sky blue 60 cc
     6 230ah GC @36 volts 
    18 amp accusense charger. 3650 champion 
    · Share on Twitter
  • mountainman
    mountainman Registered Users Posts: 439 ✭✭
    #13
    My arrays are 380 on mppt range is 20-24 amps on ~70℅ soc. And 400 on pwm 22-24.5 
    2kw array 6 345 q cells  make sky blue 60 cc
     6 230ah GC @36 volts 
    18 amp accusense charger. 3650 champion 
    · Share on Twitter

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