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Old 08-19-19, 11:00 AM   #27
Daox
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While waiting on the other electronic bits, I ordered and received mysolar panel. It measures about 18X14".





It is a 20W 12V panel sold by Newpowa. Operating voltage is 17.2V and 1.16A. This is what I will set the 'MPPT' controller to. It will maintain the 17.2V at whatever amperage the panel can supply.





I was concerned that achieving the 17.2V on a cloudy day was going to be an issue. The whole reason I went with the 12V panel was so I could get some charging done on cloudy days as I am only charging a 3.3V battery. But, my worries were quickly dismissed as I tested the open circuit voltage on the panel on an overcast day. I edited the brightness of this picture to accurately show what kind of light the panel was seeing. I hooked up the wire leads to the voltmeter and it was showing a nice 19.8V! So, even on cloudy days it should have no problem hitting the 17.2V. How much amperage we can get is obviously going to be low, but at least it will be something.





This is roughly how the panel will bit sitting for now. I may 3d print some sort of mount to hold it at a bit of an angle or something. We will see how it does.

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