Controller-Monitor-Panels Questions for Wilderness School

Anima Center
Anima Center Registered Users Posts: 16 ✭
in Off Grid Solar & Battery Systems #1
We are moving ahead with remaking our solar system at our off grid wilderness school. I have some questions still, if anyone can help with suggestions:

1) We will have 2 separated battery banks now, an AGM bank and a flooded bank separated by 2 Blue Sky Bank Switches and powered by 2 separate arrays. Is there a way to use a battery system monitor like the TM-2025 to simultaneously or alternately monitor both banks?

2) We'll be using 2 separate controllers and want to be able to keep an eye on our solar gain and load from inside the cabin. We like the Rogue mppt controller but is there a way to use a remote display with it? Or should we be getting the Morningstar with remote display instead for this purpose?

3) Our school has very little income, from student donations. What is the current recommended best deal on panel brands? We are thinking of getting 4 130watt panels for our second array. Somewhere on this forum I saw cheap UL brand panels given good reviews, what do you think of these for our use?

Thanks so much. Purchased a Honda 2000 and Iota charger as was suggested, did an equalizing charge on both our banks and even the flooded batteries individually tested fine.

-Jesse and Kiva
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  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    #2
    Re: Controller-Monitor-Panels Questions for Wilderness School
    Anima Center wrote: »
    Is there a way to use a battery system monitor like the TM-2025 to simultaneously or alternately monitor both banks?

    -Jesse and Kiva

    The product page for the TM-2025 says:

    "The TM-2025 can also monitor the voltage only of a second battery, such as a starting battery, or possibly also the input voltage of a solar array (if less than 100 volts.)"

    So...not really.


    The page for the pentametric says:

    "It measures 1 or 2 battery systems with a common negative."

    Which is a bit strange, as it would seem that it would only use one shunt for that. (?)


    I'd call Bogart.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #3
    Re: Controller-Monitor-Panels Questions for Wilderness School

    My two cents recommendation... Don't bother with spending the "extra money" on remote displays for the charge controllers.

    You would be better off purchasing two Battery Monitors (one for each battery bank) and remote run them to your cabin (check the specs. for how far you can run the remote wiring before you purchase).

    The reason (I would not) to share on battery monitor between two battery banks is the Battery Monitor has a "memory" so that it can keep track of the state of charge of each battery bank. Switching between banks, and you don't have any idea of the current state of charge.

    And towards that end--Battery Monitors tell you how much energy is going into/out of a battery bank (both charging and loads), whereas a charge controller can only tell you how much energy it is currently (and for many) historically outputting.

    What you need to do is balance charging/discharging for the battery bank (long life, properly husbanding power of your solar RE system, etc.). A battery monitor is much better at this than anything else.

    Check the pricing of Remote Meters and Computer Interfaces, they frequently are not cheap--and you have to take into account if you are running a laptop computer just to keep the logs. Sometimes, not an insignificance use of power.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Anima Center
    Anima Center Registered Users Posts: 16 ✭
    #4
    Re: Controller-Monitor-Panels Questions for Wilderness School

    Okay, sounds like two monitors it is, and no controller remotes.

    We are thinking of continuing to use our PWM TriStar 30 and purchasing an MPPT Morningstar or Rogue MPPT for the second. Thinking of putting the MPPT on the flooded bank, the old PWM on the AGM bank. Or not??

    And are Kyoceras appreciably better than the UL panels on ebay? Hoping to get the former from NAWS if we can swing it.

    This forum has been a heckuva education... whether we were ready for it or not!
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #5
    Re: Controller-Monitor-Panels Questions for Wilderness School

    Kyocera has a track record--and when they produced a lot of bad panels--they did make good on warranty. A couple threads.

    Solar Guppy's forum about Kyocera failures Mfg 1999-2001
    Wind-Sun Forum about Kyocera failures

    Even the good guys make mistakes...

    These days, I don't think you can count on 20+ year warranty coverage from any company (aka my 5 year old BP Solar Array?).

    Companies that don't have a track record--we don't know what the panels will look like in 5+ years.

    On the other hand, many of these companies build panels under their brand name and for the majors too...

    IF the "UL Panels" are actually UL Listed (as opposed to just latching onto UL's name/trademark)--Then they have passed some pretty stringent tests. But, again, UL Testing/Listing is about safety--not about whether or not the product is fit for service or will meet its warranty claims.

    -Bill "You pay your money and you take your chance" B.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Anima Center
    Anima Center Registered Users Posts: 16 ✭
    #6
    Re: Controller-Monitor-Panels Questions for Wilderness School

    So if we had only one MPPT controller, would you guys recommend using it for the Flooded bank, or the AGM bank??
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #7
    Re: Controller-Monitor-Panels Questions for Wilderness School

    I am not sure it matters... Look at the options--which one supports AGM, which one supports equalizing flooded cell batteries...

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