Low amp output

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Pchez
Pchez Registered Users Posts: 5 ✭✭
in Solar Beginners Corner #1
Hello. I have 4x120watt flexible solar panels on my van roof wired in series parallel going to a Victron 100/50 mppt cc with 2x 200ah Renogy agm batteries in parallel. I have a battery isolated/relay from my starter battery/ alternator. The panels are outputting 20 volts each as tested at each panel but about .30 amps each. The most I’ve ever seen coming out of my cc is about 4.5amps and it hasn’t left bulk charge mode since I charged the batteries through the 2000 watt pure sine wave inverter/Charger I have minimal load throughout the day and night a 12 volt refrigerator is the only load on it all the time. Are my solar panels just cheap Chinese junk or is there a possible fix I’m not seeing?
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  • Drakyla
    Drakyla Registered Users Posts: 15 ✭✭
    #2
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    Hello , newbie question here ... is it possible your batteries to be full and for that reason panels to cant produce more than 0.3amps each (guessing those 0.3 to be enough to keep the batteries full)?
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  • Pchez
    Pchez Registered Users Posts: 5 ✭✭
    #3
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    Batteries are only showing 85% soc and the charge controller stays in bulk charge state and never gets to absorption state so I can only assume the bank is not getting charged fully.
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  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    #4
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    Flexible panels are notorious for degrading over time, glass panels are far superior, if you have a clamp on ammeter you could do a short circuit current test to verify what current they can output.
    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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  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,044 ✭✭✭✭✭
    #5
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    Do you have ANY shading on these panels?

     Keep in mind that flat mounted panels will not put out full power unless the sun is directly overhead. Now that we're in the Fall season the sun's angle in the sky is getting shallower every day. 

    Also remember that hot panels will put out less power than cold ones. Panels stuck down on a hot metal roof will likely always run hotter than free air panels.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric,  460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.

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  • Pchez
    Pchez Registered Users Posts: 5 ✭✭
    edited October 2018 #6
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    I just hate to think the array I have can’t keep up with the simple loads I ask of my battery bank. All the feedback I get is greatly appreciated
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  • Photowhit
    Photowhit Solar Expert Posts: 6,003 ✭✭✭✭✭
    #7
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    A 12 volt fridge is not a small load!

    Might look at the specs of it and see what size load it is. Indeed if it's a Thermoelectric it will use more electric than a compressor fridge through out the day.
    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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  • Pchez
    Pchez Registered Users Posts: 5 ✭✭
    #8
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    I’m isolating the batteries as I believe one to be bad and drawing my bank down. I will keep posting my results.
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  • Pchez
    Pchez Registered Users Posts: 5 ✭✭
    #9
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    Ok monitoring my solar panels. (480w) is only producing about 80w on any given day. That terrible right?
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #10
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    If your battery is not at ~14.xx volts when charging, or less than ~13.2x volts when floating, yes, that does not sound correct.

    My personal line has been, when I assume the system should be supplying "full power", I use 50% of rated output as the divide between things are working "ok" and something "is really wrong"...

    Unfortinatually, for solar+charge controllers, we really need the details. What are the Vmp/Imp rating of the panels (it sounds like 2series x 2parallel connections).

    What is the voltage on the Vpanel input of the charge controller (somewhere around 10am to 2pm, panels in full sun and pointing roughly at sun). (should be ~35.00 volts for your array with controller pulling Pmax power).

    What is the voltage on the charge controller Vbatt terminals (~14.40 volts for Absorb AGM).

    Vbattery-bus should be around 14.30 to 14.35 volts (~0.05 to 0.10 volts cable drop at full charging current).

    And what is the Vbatt charging current...

    Charge controller should be in "bulk" or "absorb" stage charging... If in "float"--something else....

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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