Off grid cabin upgrade help

spanel
spanel Solar Expert Posts: 36 ✭✭
in Solar Beginners Corner #1
Current setup
2 135 12v panels
2 6v 220ah batteries

We have had this setup on our small cabin(hunting/rec we dont live here) for 8 years and its time for an upgrade.  This has served us well as we have a backup inverter genny (2800watt).  It lasts about a day or so cloudy and we have to run the genny after that.

Here is what I am thinking to upgrade.

6 x 325watt 24v panels
8 x 6v 220ah batteries.
Magnum RD1824 invertor/charger

I know it will be better than what we have.

This will be 4x more runtime?
What will be a good charge controller?
Thoughts?

Thanks

Chris


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Comments

  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    #2
    Any particular reason for 24v nominal bank voltage?  As you're replacing the inverter anyway, you might want to consider 48v, which would give you the same storage in a single string, and require 1/2 the controller amp capacity.
    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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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    edited November 2019 #3
    Where will the solar Charge Controller be located ?  Would noise from a fan be objectionable (sun hours only) ?

    I have 2 I like and use
    fanless  Morningstar MPPT 60 (with integral web server)
    fans   Classic 150 ( also has ethernet port for use with Local App )

    And I agree with Estragon's 48V suggestion

    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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  • softdown
    softdown Solar Expert Posts: 3,819 ✭✭✭✭
    #4
    Yea - plenty strong paneling to warrant the 48 volt upgrade - which has no downside that I am aware of. Suddenly your wiring acquires twice the efficiency and capacity. 
    First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    #5
    Main downside IMHO used to be a lack of decent small (eg 300w) PSW 48v inverters, though there are a few now.

    Also, there are lots of common loads that can use 12vdc, fewer use 24v, and even fewer use 48v.
    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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  • littleharbor2
    littleharbor2 Solar Expert Posts: 2,044 ✭✭✭✭✭
    #6
    Unless you're on a tight budget you can set up a separate 12 volt system. Usually these don't need to be large, I have a single 120 watt 12 volt panel PWM controller and a couple 6 volt deep cycle batteries powering a VHF marine base radio, a Sure-flo water pump and 12 volt stereo. This puts very little stress on the batteries, which probably never get below 90% soc.

    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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