Different panel

peterjack
peterjack Registered Users Posts: 1
My question regards using different 12V panels with others. I have the 45w Harbor Freight set up and was given two Sharp 75w panels. Can I put them all together and if so, should I use an MPPT controller or will a Morningstar 20 be OK?

Comments

  • myocardia
    myocardia Solar Expert Posts: 118 ✭✭✭
    edited July 2017 #2
    You cannot mix disparate panels using an MPPT charge controller, period. If you had one, and "added" the two 75 watt panels to your current three 15 watt panels, you'd gain 30 watts worth of power. Your two 75 watt panels would become two 15 watt panels, to match your three current 15 watt panels. Any PWM charge controller, especially a Morningstar (my favorite portable PWM controller) will work great, as long as it can handle the total combined amperage, which your Morningstar 20 amp can with ease.. Good thing you already had one, huh? :D Oh, and welcome to the forum.
    DoD= depth of discharge= amount removed from that battery   SoC= state of charge= amount remaining in that battery
    So, 0% DoD= 100% SoC, 25% DoD= 75% SoC, 50% DoD= 50% SoC, 75% DoD= 25% SoC, 100% DoD= 0% SoC
    A/C= air conditioning AC= alternating current (what comes from the outlets in your home) DC= direct current (what batteries & solar panels use)
  • fratermus
    fratermus Registered Users Posts: 48 ✭✭
    myocardia said:
    You cannot mix disparate panels using an MPPT charge controller, period. If you had one, and "added" the two 75 watt panels to your current three 15 watt panels, you'd gain 30 watts worth of power. Your two 75 watt panels would become two 15 watt panels, to match your three current 15 watt panels.
    I am having difficulty parsing this argument:

    1.  it can't be done
    2.  when done, it doesn't work very well.

    Related:  there is a neat series of YT videos where AltE tested various configurations of mismatched panels.












  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Paralleling 12V nominal panels with different power output using a PWM controller is not a problem, MPPT is a different story, 195W with a 20A controller  (PWM ) should be fine.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Panels can easily be added in series or parallel.
    To add in series, the AMPS must match within 10% of each other. The array amps will be limited to the lowest amp panel.
    To add in parallel, the Volts must match within 10% of each other.  The array voltage will the the voltage of the lowest panel.
    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 ,

  • myocardia
    myocardia Solar Expert Posts: 118 ✭✭✭
    fratermus said:
    myocardia said:
    You cannot mix disparate panels using an MPPT charge controller, period. If you had one, and "added" the two 75 watt panels to your current three 15 watt panels, you'd gain 30 watts worth of power. Your two 75 watt panels would become two 15 watt panels, to match your three current 15 watt panels.
    I am having difficulty parsing this argument:

    1.  it can't be done
    2.  when done, it doesn't work very well.

    Related:  there is a neat series of YT videos where AltE tested various configurations of mismatched panels.












    LMAO, yeah my first sentence would have been better elucidated had it instead been, "You should not mix disparate panels, period." I would think it fairly indisputable that the OP got the gist, though. ;)
    DoD= depth of discharge= amount removed from that battery   SoC= state of charge= amount remaining in that battery
    So, 0% DoD= 100% SoC, 25% DoD= 75% SoC, 50% DoD= 50% SoC, 75% DoD= 25% SoC, 100% DoD= 0% SoC
    A/C= air conditioning AC= alternating current (what comes from the outlets in your home) DC= direct current (what batteries & solar panels use)