SunSaver SS-15MPPT with 200 watts of PV ?

easytim
easytim Solar Expert Posts: 57 ✭✭✭✭
in Solar Beginners Corner #1
Morningstar - SunSaver MPPT Charge Controller Model SS-15MPPT

The SunSaver MPPT charge controller is designed for 12V and 24V battery charging from PV modules with a maximum open circuit voltage of 75V. Use up to three 36-cell modules in series.

It can be used with 200 watts of PV when charging a 12-volt battery and up to 400 watts when charging a 24-volt battery.

I have a question,

I want to buy two 130 watt solar panels and use the SunSaver SS-15MPPT

My PV panels together produce 260 watts. will this work with the SS-15 MPPT?
It says it can be used with 200 watts, I'm not sure I understand what the 200 watts means.

Please give me a little help with this
· Share on Twitter

Comments

  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    #2
    Re: SunSaver SS-15MPPT with 200 watts of PV ?

    What is the Vmax power of the panels you are buying. If it's not more than 19V, the MPPT gains will be very small. The "magic" of MPPT happens with a high voltage array, being down converted to the battery voltage, allowing for smaller gauge array wires.

    In your case, 260w of PV, *.8 (thermal de-rate) = 208W
    So unless you have PERFECT tracking of the sun the entire day, your array will likely still be just under the 200W limit. Any brief peaks, the MPPT controller just throttles back to save itself, and then continues after it cools down. But you are at it's hairy edge.
    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 ,

    · Share on Twitter
  • BB.
    BB. Super Moderators, Administrators Posts: 33,637 admin
    #3
    Re: SunSaver SS-15MPPT with 200 watts of PV ?

    I agree with Mike on the solar panel power output...

    My GT system (warm side of the SF California Peninsula) typically runs about 2.5-2.7 kWatts maximum on 3.5 kWatts of roof top panels... Very rarely (a couple times a year for not very long) will I see near 3.0 kWatts:

    2.7/3.5= 0.77
    3.0/3.5= 0.86

    260 Watts * 0.77 = 200.2 Watts
    260 Watts * 0.86 = 223.6 Watts

    If you are in a warmish area (60-90F) with roof mounted panels--you will probably be at or below the controller's limit 98+% of the time. And you will be controller limited by about 10% reduction in panel output.

    If this is will be a very cool/cold/windy area with pole mounted array--you may wish to get a larger controller (the new TriStar, in another thread, is "due" in September--may be an interesting product to look at).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
    · Share on Twitter
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    #4
    Re: SunSaver SS-15MPPT with 200 watts of PV ?

    Nothing "hairy" about it, The SunSaver can run 24/7 at 45C ambient at its rated current levels, its a 15 amp controller. If your charging at 14.4 , that 216 watts , or 432 watts for 28.8V, these are Bulk charging levels for typical battery's

    For 260 watts of PV, you will probably never see any loss as you have to have the panels at 25C, 1000wmsq ( most locations are low 900s , this is the irradiance or strength of the sun ) and perfect angle to the Sun, none of which happen unless you on a high mountain, cold conditions and you have 2 axis tracking. Typical peak from those to panels will be just @ 200 watts.

    You can run in series or parallel, at these power levels and typical temperatures it makes little difference to the mppt, you only need to be slightly above the charging voltage to have the Mppt 100% active. Even in my hot Florida climate, I am always above the bulk charging voltage with my panels typical about 65C on the roof. For an extreme location like the desert, then the two panels would be best in series.
    · Share on Twitter
  • easytim
    easytim Solar Expert Posts: 57 ✭✭✭✭
    #5
    Re: SunSaver SS-15MPPT with 200 watts of PV ?

    Hey solar guppy,

    So the SunSaver SS-15MPPT -15L will work well with two 130 watt panels in parallel then. Thats good news for me, I have ordered this combo. The hands on will help me understand its use better

    Each solar panel is 12vdc @ 7 amps each
    · Share on Twitter
  • easytim
    easytim Solar Expert Posts: 57 ✭✭✭✭
    #6
    Re: SunSaver SS-15MPPT with 200 watts of PV ?
    mike90045 wrote: »
    What is the Vmax power of the panels you are buying. If it's not more than 19V, the MPPT gains will be very small. The "magic" of MPPT happens with a high voltage array, being down converted to the battery voltage, allowing for smaller gauge array wires.

    In your case, 260w of PV, *.8 (thermal de-rate) = 208W
    So unless you have PERFECT tracking of the sun the entire day, your array will likely still be just under the 200W limit. Any brief peaks, the MPPT controller just throttles back to save itself, and then continues after it cools down. But you are at it's hairy edge.


    Thanks for the info - here is the panel I will be using
    http://www.wildnaturesolutions.com/solarpanels.html

    Vmax 19.8V
    The 130 watt panel


    .
    · Share on Twitter

Categories