Kaneka gsa-60 panels

Hello I am thinking about ordering two kaneka 60 watt panels but they are 48 volt ,what is the least exspensive charge controller that I can use to charge batteries for a 12volt system .And can I run a fan directly from the panels for my solar kiln . Thank you

Comments

  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: Kaneka gsa-60 panels

    The Kaneka GSA-60 is a nominal 60 W / “48 V” module. However, its STC Vmp is 67.0 V, and its STC Voc is 91.8 V. These specs automatically rule out a small MPPT controller such as the Morningstar SunSaver MPPT (75 V input limit).

    The module’s V specs will be inversely affected by ambient temperature. The specific concern here is that the Voc will be higher if your local ambient record low temperature is below the STC spec of 25 C (77 F). Accordingly, we need to know more about where you live, or, you can go to someplace like www.weather.com to search for your area’s record low temp and provide us with that data.

    Once we have that info, we can help you find a compatible MPPT charge controller. However, it’s my gut feeling that the pickin’s will be slim. An alternate solution might be a single "12 V" module like this one connected to an appropriately sized PWM controller and then on to a "12 V" battery.

    Also, can you provide more info about the fan: Voltage? Current? Power? Anything?

    Regards,
    Jim / crewzer
  • BB.BB. Super Moderators, Administrators Posts: 28,645 admin
    Re: Kaneka gsa-60 panels

    With Vmp=48 volt panels and a 12 volt battery bank... The only efficient way to charge the battery bank is with a MPPT type charge controller--which is probably 2x the cost of a PWM charge controller.

    All About Charge Controllers
    Read this page about power tracking controllers

    Xanterx, Morning Star, and Rogue all make nice MPPT type charge controllers.

    The Xantrex is too big (60 amp), MorningStar has a nice 15 amp (at 12 volts would support a bit over 200 watts of solar panels-they also have models in 45 and 60 amps), and Rogue is a 30 amp controller.

    However, looking up the Kenaka specs:
    Pmax @ STC 60 W
    Pmax @ PTC 56 W
    Vmp at Pmax 67 V
    Imp at Pmax 0.9 A
    Voc @ STC 92 V
    Voltage change -280 mV/C

    You will be limited to the Xantrex or larger Morning Star products (45 amp or 60 amps) because the Voc can be as high at 102 VDC at 14F (assuming you are in San Bernardino area)... For hot temperatures, the Vmp is down around Vmp=52vdc at 110F... A bit low for properly charging a 48 volt bank in summer--but find for 12 or 24 volt banks. (data from Xantrex XW string sizing tool)

    Otherwise, you would have to look for "12 volt" solar panels (Vmp around 17 volts) for use with the less expensive PWM type charge controllers.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Solar GuppySolar Guppy Solar Expert Posts: 1,959 ✭✭✭
    Re: Kaneka gsa-60 panels

    Only the Xantrex XW-Mppt, the MorningStar TriStar Mppt ( not sunsaver ) and the Outback FM series would be appropriate for this panel as the VOC can easily be over 100V which is over both the Rogue and the Sunsaver Mppt maximum input voltage allowed
  • System2System2 Posts: 6,290 admin
    Re: Kaneka gsa-60 panels
    Hello I am thinking about ordering two kaneka 60 watt panels but they are 48 volt ,what is the least exspensive charge controller that I can use to charge batteries for a 12volt system .And can I run a fan directly from the panels for my solar kiln . Thank you
    I was going to buy these panels because they are a good price and the sales man was saying that the c-40 xantrex would work for 2 panels so he is wrong? Thank you .Brian
  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: Kaneka gsa-60 panels
    sales man was saying that the c-40 xantrex would work for 2 panels so he is wrong?
    Assuming he clearly understands your application ("48 V" array to 12 V battery), then, yes, he's wrong.

    The C-40 is a PWM-type series controller, and it's designed for use with systems where the nominal PV array voltage is the same as the nominal battery voltage, i.e., "24 V" PV array to 24 V battery bank, or "12 V" PV array to 12 V battery bank.

    The C-40 can't do DC-DC step-down conversion, so it won't work (very well, if at all) with your notional "48 V" array -> 12 V battery configuration.

    A separate but related issue is that the "big" MPPT controllers won't work very efficiently with a 120 W (STC) array stepping down from 48 V to 12 V. And, they ain't inexpensive.

    HTH,
    Jim / crewzer
  • BB.BB. Super Moderators, Administrators Posts: 28,645 admin
    Re: Kaneka gsa-60 panels

    And if you are in the southern California desert area---Those panels will not charge a 48 volt battery bank in 100+ degree weather using either a PWM or MPPT charge controller.

    And as Jim says--a 120 watts of solar panels does make sense for a $400-$500+ controller is not cheap when spread across 120 watts of solar panels (you are paying almost $3 per watt extra to use this panels).

    For a small system, you would be better off paying $2.68 a watt for a "12 volt" 135 watt panel and a simple PWM charge controller (note: prices are subject to change--I am not connected in anyway with NAWS other than as a moderator to control spam).

    Kyocera KD135GX-LPU 135 Watt 12 Volt Solar Electric Panel
    Weekly Special - Kyocera 135 Watt 12 Volt, with MC4 cable connections
    Our Discounted Price: $362.85, 2 for $720.00, 8 for $2,800.00

    ProStar 15 solar charge controller with digital meter
    15 Amp Solar Charge Controller
    Our Discounted Price: $161.92


    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: Kaneka gsa-60 panels

    Thank you all for you information. Brian
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: Kaneka gsa-60 panels
    I was going to buy these panels because they are a good price and the sales man was saying that the c-40 xantrex would work for 2 panels so he is wrong? Thank you .Brian

    Sounds like that salesman is clueless. Not ony would you lose around 75% of your wattage, the voltage on those panels is too high for the C40, or in fact most of the standard charge controllers.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,959 ✭✭✭
    Re: Kaneka gsa-60 panels
    Windsun wrote: »
    Sounds like that salesman is clueless. Not ony would you lose around 75% of your wattage, the voltage on those panels is too high for the C40, or in fact most of the standard charge controllers.

    Actually, the Xantrex C40 is good to 125V ... I agree a waste of watts but nothing bad would happen to the controller
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: Kaneka gsa-60 panels
    Actually, the Xantrex C40 is good to 125V ... I agree a waste of watts but nothing bad would happen to the controller

    Yup, you are correct, for some reason I had it in my mind that the C40 was 90 volts max. I guess that is what happens when you get old and senile.
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