sorta new here

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218floodave
218floodave Registered Users Posts: 6 ✭
in Solar Beginners Corner #1
I am preparing to build a solar system for my 2001 Ford E350 xl and have an extended yakima megawarrior on a bubbletop. I was ebay'ing and picked up 2 large matched panels made by Sunbolts one will fit in the rack. I am a bit concerned about driving with such a large panel and not too sure of the output no information to be found on the panels but they look new and leftover from a home install. I have a good multymeter.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #2
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    Re: sorta new here

    Welcome to the forum Dave!

    It looks like Sunbolt may just be the brand of junction box--And not the actual panel manufacturer.

    Are the panels crystalline panels (round or square silicon cells (and if so, how many cells) or is it "thin film" (uniform black solid panel, usually with small lines in the material)?

    You cannot do anything until you know something about the solar panels. In any sort of sun, measure the open circuit voltage of the panel with your volt meter. It will probably be somewhere between 20 volts and 30-40 volts in full sun (possibly 60-80 volts in rare cases--so be careful not to get shocked).

    Next, depending on the size of the panel (length by width), face the panel against a wall, or cover with a dark blanket/cardboard box, set your meter to 10 amps full scale and slowly point/uncover the panel and point it at full mid-day sun. And see what the short circuit current is.

    Once we have these two values, we can at least begin to figure out what kind of hardware you need to charge your (I guess) 12 volt battery bank.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • 218floodave
    218floodave Registered Users Posts: 6 ✭
    #3
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    Re: sorta new here

    Here is the exact listing they measure 3.5 ft. x 5.4 ft
    http://www.ebay.com/itm/121151503627?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2648

    If I cannot use them on my truck I will set them up on my stix-n-brix
    Thanks for saying hi and responding Adrian
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #4
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    Re: sorta new here

    Hi Adrian,

    This looks like a Vmp~30 volt panel. And based on size is probably a 250-270 panel with Imp~8.33 amps or a bit more. If you measure the panel by quickly exposing it to the sun, you should see ~38 volts measured with a volt meter (as panel gets hot, Voc will begin to fall a few volts).

    At this point to charge your 12 volt battery bank, you will need a minimum of 15 amp MPPT type charge controller for one panel. And a minimum 30 amp controller for two panels (two panels in parallel or series--Depends on charge controller input specifications). A couple of possible charge controllers include:

    MorningStar 15-60 amp MPPT controllers
    Rogue 30 amp MPPT controller
    Midnite is about to introduce a family of smaller MPPT controllers (not available yet)
    Outback--Larger MPPT controllers

    With any of these controllers, I would recommend the Remote Battery Temperature Sensor option--And especially for the small MorningStar 15 amp MPPT.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • 218floodave
    218floodave Registered Users Posts: 6 ✭
    #5
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    Re: sorta new here
    BB. wrote: »
    Hi Adrian,

    This looks like a Vmp~30 volt panel. And based on size is probably a 250-270 panel with Imp~8.33 amps or a bit more. If you measure the panel by quickly exposing it to the sun, you should see ~38 volts measured with a volt meter (as panel gets hot, Voc will begin to fall a few volts).

    At this point to charge your 12 volt battery bank, you will need a minimum of 15 amp MPPT type charge controller for one panel. And a minimum 30 amp controller for two panels (two panels in parallel or series--Depends on charge controller input specifications). A couple of possible charge controllers include:

    MorningStar 15-60 amp MPPT controllers
    Rogue 30 amp MPPT controller
    Midnite is about to introduce a family of smaller MPPT controllers (not available yet)
    Outback--Larger MPPT controllers

    With any of these controllers, I would recommend the Remote Battery Temperature Sensor option--And especially for the small MorningStar 15 amp MPPT.

    -Bill
    Thanks all that info from a picture wow I am looking at this meter Morningstar RM-1 Remote Meter I already have the small morningStar 15 MPPT. My truck is at Left Coast diesel in concord getting a set of injectors 3000 bucks ouch and my multy is in the tool box inside the truck so I will have to wait to test. I might have just lucked out with the panels..
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #6
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    Re: sorta new here

    You are very welcome--And not to give away all of my magical secrets...

    The picture showed 10x6 cells. That means they are either mono or crystalline cells. And each cell is Vmp~0.5 volts per cell. And most of these types of panels are wired in series of 60 cells or ~Vmp=30 volts.

    And I took the looked at the measurements on the posting, and compared those to a 250 watt crystaline panel--And it was just a little bit larger--So probably around 250 watts or so...

    Math: P=V*I; I=P/V; I=250W/30V=8.3 amps

    All guesses (and we have been surprised before by "non-standard" panel configurations)--But probably close enough for you to make design decisions--Just need you to confirm Voltage Open Circuit (Voc) to be pretty sure.

    By the way, if you are going to be working with DC power and solar (and multi-string battery banks), I would suggest getting a "cheap" DC Current Clamp meter from Sears (at the very least--An AC/DC current clamp meter from Fluke would be good too)--Very nice for working on debugging/monitoring the health of your system.

    -Bill "don't pay attention to the man behind the curtain" B.
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • 218floodave
    218floodave Registered Users Posts: 6 ✭
    #7
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    Re: sorta new here
    218floodave wrote: »
    Thanks all that info from a picture wow I am looking at this meter Morningstar RM-1 Remote Meter I already have the small morningStar 15 MPPT. My truck is at Left Coast diesel in concord getting a set of injectors 3000 bucks ouch and my multy is in the tool box inside the truck so I will have to wait to test. I might have just lucked out with the panels..

    Well you are right on spot here 35.5 volt on a typical slight overcast day at high noon in San Francisco (I live in an area called the sunnyside seems like oxymoron it's usually very cloudy here) That Morningstar 15mppt should do the trick with one panel and 2 x 6 volt batteries. I will be getting the remote temp after licking my wounds on the injectors replacement. I would like to keep it really simple as I am not ac/dc savvy a little more the sensitive artistic type. But simple I get. a bank of dc cig plugs would work well for me. Do you think I'm barking up the right tree?
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  • 218floodave
    218floodave Registered Users Posts: 6 ✭
    #8
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    Re: sorta new here

    I did have one of these Greenlee CMI-100 a perk from working in a pawn shop for the last 30 years, glad that's over with!! it did buy me a house.
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  • 218floodave
    218floodave Registered Users Posts: 6 ✭
    #9
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    Re: sorta new here

    any opinion on this device for 2 x 6 volt deep cycle SAMLEX SSW-600-12A 12 VOLT 600 WATT PURE SINE WAVE INVERTER W/ USB CHARGING PORT I don't think I will need anything bigger?
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