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diy solar

Need help with small off grid cabin panels

Tat2rtist

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Joined
Sep 6, 2020
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I purchased a Midnite Solar MN3024DIY inverter/charger, I have 4 brand new panels, and a Big Battery 24 V Husky Elite 234AH, 6 KWh battery. would like some help with figuring best configuration for panels. Below are pics of the inverter manual and panel stickers. All components are brand new.
This is a camp that is used mostly during hunting season , also power will be supplemented with generator to pick up any slack in solar charging.
I am not sure which configuration would be best possible configuration , below are what I think are the the configuration numbers if what I figured out is correct.
2 two panel series in parallel - 460 watts, 62 volts, 15A
4 panels in parallel - 230 watts, 31volts,30amps
4 panels in series- 920 watts 150 volts 7.4 amps ( which I am pretty sure is too high of voltage)
Below are pictures of manual and panel stickers, any advice is greatly appreciated.

 

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Your math is incorrect. Four panels will be a total of 920W irregardless as to whether you wire them 4S1P, 2S2P, or 1S4P.

I would suggest that 2S2P is the best configuration. Voltage will drop in the hot days of summer, and the 31V could drop a bit too low to completely charge that battery, which has a charging specification of 29V.

You absolutely can NOT have all four panels in series. This inverter has a max temperature corrected voltage of 100V, and four in series would reach 124V. That WILL damage the electronics. Whether or not the unit will actually start a fire, I can't say.

So, 2S2P works best. It's about in the middle of the optimal MPPT range, and the extra voltage will help reduce resistance through the wiring. That means a bit thinner/cheaper copper wire can be ran from the array to the inverter. Use this calculator. https://www.calculator.net/voltage-drop-calculator.html How far will the actual run from the array to the electronics be?
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