meter says 40 volt with 12volt panels

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solarsquirral
solarsquirral Solar Expert Posts: 54 ✭
in General Solar Power Topics #1
meter says 40 volts on 12 volt panels
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  • solarsquirral
    solarsquirral Solar Expert Posts: 54 ✭
    #2
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    so i just got a meter for my c60 charge controller along with battery temp sensor
    yesterday the array current said 17 volt and battery was chargeing at 15.5 volts a little high but it was about 40 degress last night so im guessing that the bts doing that
    today i look at the meter and it says 40 volt at the array whats going on i didnt change any thing i wonder whats up

    any help is appreciated
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #3
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    15.5 volts charging is a bit on the high side... Is the charge controller set to that voltage, or is there a problem?

    If the charge controller is "cold environment", the internal temperature sensor will raise the charging voltage (-5C, roughly +0.9 volts). 15.5 volts sound a bit high--Have you checked their specific gravity with a hydrometer yet?

    Also--40 volts from a "12 volt array" (really Voc~21 volts, Vmp~18 volts) sounds very high... There are Vmp~30 volt panels which could be around 40 volt Voc... Or you have two 12 volt panels wired in series--Which would not be a good match with a C60 PWM controller and a 12 volt lead acid battery bank (you could be "losing" almost 1/2 of the output wattage of your array if configured this way).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • solarsquirral
    solarsquirral Solar Expert Posts: 54 ✭
    #4
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    yeah the setting is at 15 volts these are large rolls surrite batts
    the voltage bumped up to 15.5 after i put the bts on maybe a little cold out
    none of the panels are wired together in series
    each panel is wired induvidually in a combiner
    a couple panels are shareing one slot in the combiner could that be it???
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  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #5
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    Are your panels larger than 150W ea ? if so, they are likely Grid Tie panels, with a much higher Voc than 12V (21Voc) battery charging panels. Since the C40 is a PWN controller, as the battery gets full and the charger throttles back, the PV panels will start to read closer to their Voc then the battery Volts. Perferctly normal. If you look a the sticker on the back of the panel, what does the number after Voc read ? Close or above 40V I'll bet
    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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  • solarsquirral
    solarsquirral Solar Expert Posts: 54 ✭
    #6
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    the voc is 21.7
    the panels are 75 watts
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,439 admin
    #7
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    If the panels are in parallel--Then current adds, and voltage remains Voc-single panel.

    If the panels are in series--The voltage add (2x single panel Vmp/Voc) and the current remains 1x Imp/Isc.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • Photowhit
    Photowhit Solar Expert Posts: 6,003 ✭✭✭✭✭
    #8
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    solarsquirral wrote: »
    so i just got a meter for my c60 charge controller along with battery temp sensor
    yesterday

    If I assume you have a Schnieder/Xantrex/Trace C60, there is not s dedicated meter that I am aware of...

    What meter do you have and how have you hooked it up!
    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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  • solarsquirral
    solarsquirral Solar Expert Posts: 54 ✭
    #9
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    yeah its a c60
    it has a meter that plugs into a jack on the circuit board

    its the c series meter display
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  • Photowhit
    Photowhit Solar Expert Posts: 6,003 ✭✭✭✭✭
    #10
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    I apologize, I thought only the C40 could use the meter.

    Here's a link to the meter's manual. unfortunately it offers no help, other than to suggest setting the display to dim if you have erratic readings, or you're over 100 feet away.
    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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