Marine Installation

First of all I hope this fits here?
I am installing a Kyocera KC130TM on our sailboat. It has a 2 battery system with a battery selctor switch, battery 1, battery 2, both.
I am looking for the best charge controller for the application. I have been looking at the MPPT controllers and like what they can do. I also would like to chage both batteries at the same time and also keeping them isolated from each other.
Can I install a diode in (+) wires feeding each battery from the single (+) terminal from the charge controller ? This, I would think would keep the batteries isolated and allowing them both to be charged?
Sorry, I'm new to this so be kind...
Thank You

Comments

  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Marine Installation

    that might work for you, but you would have to raise the voltage on the controller a bit higher as the diode will pose a voltage drop of around .5 to .7v. it would be best to use a digital meter to measure the voltage seen at the battery and use that put to the proper settings rather than what the cc would see. these diodes are often incorporated into commercially available battery isolators found in rv circles.
    one more thing. these diodes must be able to handle the full current the pv can output short circuited.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,980 ✭✭✭
    Re: Marine Installation

    MorningStar Sunsaver Mppt is your really only choice for this power class
  • RandomJoeRandomJoe Solar Expert Posts: 472 ✭✭✭
    Re: Marine Installation

    Maybe I'm not thinking this through correctly, but seems to me you can't use diodes in that application. If they are oriented to allow power to flow into the batteries, they won't allow the charge controller to power itself off the batteries. I know my FM80 says to have the battery power applied (and it starts / runs itself from that) before applying the solar input power.

    I supposed there might be some that could handle running themselves solely off the solar input, but then they would be completely dead if the sun is down. Also, seems they might have an issue reading battery voltage - any time they stopped charging (the off period of a PWM, or when an MPPT backs off the current, or the sun goes behind a cloud) the controller is going to see a bogus reading, possibly even think it's a "dead" 0V battery.

    The fact the RV battery isolators have diodes makes me think maybe I'm missing something, but then a car alternator doesn't operate in quite the same way as a charge controller...
  • System2System2 Posts: 6,290 admin
    Re: Marine Installation

    Thank You all for your replys,
    I never thought about powering up the charge controller, the diodes would cause a problem.
    Do you think the benifit of A MPPT is worth it or should I be thinking of using the Morning Star dual battery controller?
  • mike95490mike95490 Solar Expert Posts: 9,462 ✭✭✭✭✭
    Re: Marine Installation
    Thank You all for your replys,
    I never thought about powering up the charge controller, the diodes would cause a problem.
    Do you think the benifit of A MPPT is worth it or should I be thinking of using the Morning Star dual battery controller?

    Where are you sailing? Tropics, or cold areas? Tropic areas, you may not see much gain with MPPT vs PWM In cooler areas, where the PV puts out half a volt more, you can see a gain. All depends on the voltage from your PV.
    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 ,

  • BB.BB. Super Moderators, Administrators Posts: 32,212 admin
    Re: Marine Installation

    And remember, any shading by sails or lines, can dramatically reduce your panel output. The panels should be in full sun/no shade as much as possible.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Marine Installation

    We sail on the Great Lakes mostly Lake Michigan. The panel will be mounted on top of the bimini hopefully to minimize shading.
  • dwhdwh Solar Expert Posts: 1,341 ✭✭✭
    Re: Marine Installation

    For a single 130w panel I would probably go with the SunSaver Duo. Not MPPT no, but on one panel I don't think there will be a tremendous amount of gain by going MPPT anyway, and the wiring and setup will be a snap with the Duo.
  • SheldonSheldon Solar Expert Posts: 51 ✭✭✭✭
    Re: Marine Installation
    We sail on the Great Lakes mostly Lake Michigan. The panel will be mounted on top of the bimini hopefully to minimize shading.

    If your Bimini is aft of your backstay and has no shadows from antenna then it may work. If its under the backstay then the shadows will be a problem and will dramatically reduce your output.

    You don't specify, but I'll assume you have a 25-40' sloop, with a short boom, and the Mainsheet forward of the Bimini, like most of the plastic boats built since '80. That suggests a beam at bimini top of about 6-8 feet, and a transom of 4-6.

    Sailing in the great lakes, you won't be doing stern to mooring, so an alternative is to build a "davit top" or "radar arch" mount, where the panel(s) will be flat, outboard and elevated. A fancy mount might allow for "tacking" the array, to let you tilt it for long passages.

    Assuming you want this to work on a mooring or at anchor, Since in a slip you have shore power then you need to have a best compromise which would be flat, not elevated as you will swing in wind, and azimuth will be variable.

    If you have > 6 ft of beam for your array, then a multiple small panel array with MPPT
    would be your best bet, making it less sensitive to shade, tilt and bird droppings.

    Sheldon
    SV "Lioness"
    1962 Bermuda 40 Classic Yawl
  • Dave AngeliniDave Angelini Solar Expert Posts: 6,076 ✭✭✭✭✭
    Re: Marine Installation

    Sheldon,

    Were you "out" with Lioness in the 90's? There was a Bermuda 40 "I think" by that name that we anchored with near Cartegena. I thought she was a Ketch......

    --Dave
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
     http://members.sti.net/offgridsolar/
    E-mail [email protected]

  • SheldonSheldon Solar Expert Posts: 51 ✭✭✭✭
    Re: Marine Installation

    No, I got her in 2000, her previous name was "Harrier", she was based in NYC, had been cruised as far east as St. Johns NB to my knowledge by her original owner Dr. Rosenthiel.

    I had her berthed in Portsmouth, NH and cruised as far south on the East Coast as Nantucket and as far North & East as the Magdalene Islands of QE, via Bras D'Or Lakes of NS. If you google "Lioness" "Bermuda" you will find our not very impressive results in the PHRF New Englands, and Monhegan races.

    We brought her overland to CA in '07 on a job change and so far have barely stuck her bow out of the Golden Gate, she's berthed at OYC in Alameda and we race on the bay and estuary.

    AFAIK All B-40's were yawls or sloops, but there were some larger ketches, '49. '51 etc
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