Kyocera 250W panels and Outback Flexmax 80 Charge Controller question

[Silver_Is_Money]

Is it possible to safely wire 20 Kyocera 250 Watt solar panels into a single Outback Flexmax 80 Charge Controller? I'm in Ohio, and the record cold temperature for this state was -26 degrees F, 104 degrees F. is about as hot as it gets, though I would assume that rooftops can well exceed that. The specific model number of the Kyocera panels is KD250GX-LFB2. Voc= 36.9 volts, and Isc = 9.09 amps. Vmp = 29.8 volts, and Imp = 8.39 amps. Temperature coefficients are: Voc = 0-0.36 deg. C, and Vmp = -0.52 deg. C.

I'm trying to decide between one of the Midnight Solar Classics (150, 200, 250) and the Outback Flexmax 80. Cost seems to favor the Outback unit.

[inetdog]

Is it possible to safely wire 20 Kyocera 250 Watt solar panels into a single Outback Flexmax 80 Charge Controller? I'm in Ohio, and the record cold temperature for this state was -26 degrees F, 104 degrees F. is about as hot as it gets, though I would assume that rooftops can well exceed that. The specific model number of the Kyocera panels is KD250GX-LFB2. Voc= 36.9 volts, and Isc = 9.09 amps. Vmp = 29.8 volts, and Imp = 8.39 amps. Temperature coefficients are: Voc = 0-0.36 deg. C, and Vmp = -0.52 deg. C.

I'm trying to decide between one of the Midnight Solar Classics (150, 200, 250) and the Outback Flexmax 80. Cost seems to favor the Outback unit.

The number of panels you can put in series in a single string will be determined by the input voltage limit of the CC.
With a total of 20 panels, you have the practical choice of four, five or ten identical strings. With a Voc of 37 and a low temperature increase to maybe 55 volts!!!, you are not going to get ten panels in a string, even with the Classic 250.
Check out the combinations and decide, keeping in mind that the Classics with HyperVoc can tolerate (but not operate with) voltages up to the nominal input max plus your battery voltage. I hope that you are using a 24V or 48V battery system with that much panel power, and even then I think that even with a 48V system an 80A CC will not be able to handle all of your panel output. (Somebody else please check my math: 5000/80=62.5)
Now that extra panel power will not necessarily harm the Outback, and you will still get some benefit from the oversized array based on higher usable output in the early and late hours with output clipping around solar noon.

[Sunking]

Well with 5000 watt panel input dictates a 48 volt battery and a controller that can output 96 amps to utilize all 5000 watts of the panels. So lets make your decision real easy for you.

Outback maximum power input from panels is 4000 watts on a 48 volt battery, and 5000 watts on a 60 volt battery.
Midnite Solar Classic 150 has a 5020 watt maximum input at 48 volt battery. The controller is underrated and is really a 96 amp controller.

Kind of makes it an easy choice huh?

[Silver_Is_Money]

Thanks SunKing! I went to the Midnight Solar website and located their Classic sizing tool. It does say that if these panels are arranged into 10 strings of 2 panels the Classic 150 will handle it, Max watts for this configuration = 5,022.

[Sunking]

Thanks SunKing! I went to the Midnight Solar website and located their Classic sizing tool. It does say that if these panels are arranged into 10 strings of 2 panels the Classic 150 will handle it, Max watts for this configuration = 5,022.

Doh! only missed it by 2 watts

[mapmaker]

Midnite Solar Classic 150 has a 5020 watt maximum input at 48 volt battery. The controller is underrated and is really a 96 amp controller.

With some array configurations it can push 96 amps into a 12 volt battery. On no array configuration can it push more than 86 amps into a 48 volt battery.

--mapmaker

[Sunking]

With some array configurations it can push 96 amps into a 12 volt battery. On no array configuration can it push more than 86 amps into a 48 volt battery.

Yep my bad going off memory. 86 amps @ 5022 watts @ 48 volt nominal battery running 70 Vmp . Still smokes the Outback.