Will This Work ????????

Gregory J BarrettGregory J Barrett Registered Users Posts: 5
Each panel has 24 cells

Comments

  • mike95490mike95490 Solar Expert Posts: 7,249 ✭✭✭✭
    Re: Will This Work ????????

    It will work to provide 12VDC, if the 24 cells are all in series. Your sketch is oversimplified, and I'm not sure what it is showing with 8 rectangles ?

    It won't recharge a battery though, you need about 15V at the terminals to recharge.

    Are these planned, or already built ?

    If already built, you need to use 2 in series and a MPPT charge controller to charge a 12V battery.
    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 ,

  • Gregory J BarrettGregory J Barrett Registered Users Posts: 5
    Re: Will This Work ????????

    Each colem has eight .5 volt 4 watt cells connected in series ...
    3 columns per pannel connected in parallel
    five panels connected in series giving me 19 volts
    Yes I have built and I thought parallel columns would give me more power.
  • mike95490mike95490 Solar Expert Posts: 7,249 ✭✭✭✭
    Re: Will This Work ????????

    you are correct, cells in parallel add power. So you have 12W @ 4V each panel, 12w @ 16 v = .75A under perfect conditions.

    32 cells in series = 16VWell, you may just barely be able to slowly charge a battery. I would remove all the diodes, except for the ones in one panel. You loose a volt across each diode. keep one set of diodes to prevent the battery from discharging at night
    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 ,

  • Gregory J BarrettGregory J Barrett Registered Users Posts: 5
    Re: Will This Work ????????

    Cells are .5 volt 4 watt.... Each column has 32 watt....
    3 colums in parallel each panle = 32 watt Right
    now tie 4 panles (4 volts each) in seires = 16 volts ...32watt ???
    It's just not charging my 4 12vdc batteries connected in parallel
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Will This Work ????????

    The basic math:

    0.5 Volts * 8 = 4 Volts, 4 Watts * 8 = 32 Watts (8 Amps) each string ("column").
    Times three strings; each panel is 4 Volts, 24 Amps, 96 Watts.

    Four of these in series yields: 16 Volts, 24 Amps, 384 Watts.

    But like Mike said to begin with: you won't charge a 12 Volt battery from 16 Volts (especially not if it's Voltage open circuit). A normal "12 Volt" panel has a Vmp of 17.5 - 18 Volts and a Voc of 20+.

    Build another panel, put it in series, and get 20 Volts, 24 Amps, 480 Watts. ;)
  • BB.BB. Super Moderators Posts: 26,758 admin
    Re: Will This Work ????????
    Each colem has eight .5 volt 4 watt cells connected in series ...
    3 columns per pannel connected in parallel
    five panels connected in series giving me 19 volts
    Yes I have built and I thought parallel columns would give me more power.

    A later post shows 5 panels in series, not the 4 from the drawing...

    5 panels will be Vmp-array~19-20 volts... A little "hot" for a simple PWM controller so your efficiency will be a bit less (maybe 10% less unless you install a MPPT type charge controller--way more expensive).

    Nominally, 36 cells at ~17.5 volts is used for charging a 12 volt battery bank.

    Nothing will be hurt/damaged by ~19.5 volt panels that I would expect.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Gregory J BarrettGregory J Barrett Registered Users Posts: 5
    Re: Will This Work ????????

    Thanks You All for the help.
    My controller is a Coleman Air diversion Controller
    160amp
  • Gregory J BarrettGregory J Barrett Registered Users Posts: 5
    Re: Will This Work ????????

    ? what is... Vmp...PWM....MPPT
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Will This Work ????????
    ? what is... Vmp...PWM....MPPT
    Vmp is Voltage at maximum power.
    PWM is Pulse Width Modulation.
    MPPT is Maximum Power Point Tracking.
  • ggunnggunn Solar Expert Posts: 1,973 ✭✭✭
    Re: Will This Work ????????
    mike90045 wrote: »
    you are correct, cells in parallel add power.
    Just to be clear, cells in series add power as well. Cells in parallel add current leaving voltage the same, and cells in series add voltage leaving current the same. Power = current times voltage, so either connection adds power.
  • BB.BB. Super Moderators Posts: 26,758 admin
    Re: Will This Work ????????

    A couple FAQs about charge controllers:

    All About Charge Controllers
    Read this page about power tracking controllers

    PWM are pulse width modulation--basically just an switch that is turned on and off (rapidly or slowly--depending on the design). Less expensive to design and manufacture and good where solar panels match battery bank voltage (Vmp ~ 17.5 volts for a 12 volt battery bank--really you need about 14.5 to 15.0 volts to charge/equalize a battery bank; plus Vmp falls as the panels get hot in the sun).

    MPPT are maximum power point tracking controllers. They are a digital switching power supply between the solar panels and the battery bank. A MPPT controller can take high voltage/low current of a solar array and efficiently down convert it to low voltage/high current required to charge the battery bank.

    With MPPT, you can use solar panels with other than standard Vmp ratings, and you can make a ~100 VDC Vmp array and use much smaller gauge wire from the array to the charge controller--Very nice for high power systems and/or longer wiring runs from array to battery shed. But, MPPT controllers are much more expensive (PWM are $50 to $150... MPPT are $300 to $600+).

    You have a diversion controller that is typically used with Wind/Water Turbines. When the battery is "full", the diversion controller turns on to dump the extra energy to a heater bank or other load. Diversion controllers are used because turbines will over-speed if not always connected to a load (battery, heater, etc.).

    Solar panels can be turned on and off without damage--And the "quality" of charging for batteries is actually much better than that with a diversion controller.

    You would be much better off using a series solar charge controller to charge the battery bank than a diversion. Solar Chargers will quickly charge and maintain the charge more accurately than diversion type controllers.

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