12v System Connection configuration Questions

Ungridded
Ungridded Registered Users Posts: 4 ✭
in Solar Beginners Corner #1

Hello, My system contains the following...

6 - Kyocera KC130TM solar panels. (21.9Voc 8Amps)/(17.6Vpm 7.39Ipm)

1- Outback Flexmax 80 controller

1 - Xantrex SW2512 Inverter

4 - Trojan L16E-AC 370 AH @ 20hr

The system is going to be set up as 12v DC and my question is this... Can I connect my panels in series-parallel in two strings to roughly get 35v @ 16 Amps. so as to charge the batteries more effectively?

Thanks in advance.

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Comments

  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #2
    Pretty much have to run them 2 in series! 17.6 volts is not enough room above the charging voltage for the mttp type charge controller to work properly. I think you will be charging at about 5% during sunny days might want to add some panels if you will be using this daily. Fine for a weekend cabin...
    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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  • Ungridded
    Ungridded Registered Users Posts: 4 ✭
    #3
    Thanks Photowhit, Yes this is an off-grid weekend cabin. We only use it once or twice a month for a few days at a time. So, would it be better to connect all of the panels in series for ~105v @ 8Amps? or Series-parallel should double the voltage AND current no? or Should I not worry about the current for charging the batteries?
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #4
    No more than 3 panels in series, otherwise you will start loosing power in the controller.   3 in series may give you enough headroom to move to a 24V battery bank, but you have few options with 6  panels and 12V
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

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  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #5
    Like Mike said.

    3 in series also has the advantage of not requiring a combiner box!
    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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  • Ungridded
    Ungridded Registered Users Posts: 4 ✭
    #6

    So, if these are my panels, would this connection be correct? Sorry, This is a first for me.



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  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #7
    Yep! In general, your charge controller would run cooler with 2 in series and 3 parallel strings but you would want a combiner box (fuses or breakers) for each string. Heat and electronics don't mix well. I like that you could move to a 24 volt system without changing the configuration. Many find that loads grow and would want to move to a higher voltage system in time.
    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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  • Ungridded
    Ungridded Registered Users Posts: 4 ✭
    #8
     Photowhit, Thank you for your opinion and guidance. I very much appreciate it.
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  • Photowhit
    Photowhit Solar Expert Posts: 6,006 ✭✭✭✭✭
    #9
    I just got there first, lots of sharp people here!
    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.
    · Share on Twitter

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