Alt Power
In 2011, I finished “The Bitx20a”. It’s a 6 watt pep 20 mtr xcvr in the upper left pic. Keeping with the field day spirit, I constructed an alternative energy source. The small suitcase panels provided 13 watts with out a charge controller into an Optima blue top 12V 60 AH battery. It worked beautifully except the kids thought it would be fun to jump over them and quickly took out the panels. So… I thought to myself, self, I need an upgrade, so I purchased a set of 4 panels for a total of 80 watts and tall enough so the kids wouldn’t try to hop over them. With a charge controller, the 80-watt solar panel kept my 12V deep cycle happy. Notice the battery box… I made this before it was cool and marketed by others with an Anderson power pole. Also, mine had a 400w power inverter on the back… They didn’t copy that yet… Who knows, maybe they did.
Now, It’s Spring 2020 and I’m getting ready for field day. A case of beer is in the fridge chill’n, check. New IC 7300 with HRD software and EFNRW (End fed Non-resonate wire), loads 10-40mtrs, check. Solar panel output after 12+ years of service… Nut’n. Since the 4 panels are wired in series and 3 of then completely died, panel output was very low… Time for an upgrade. So, I went with 2 polycrystalline 80watt panels, that measured 26 x 30 inches. I created custom brackets and mounted them on 6×6 deck supports. They both came with a 12 Amp charge controller and a 200w inverter. The charge controller was acting intermittently so being the amateur radio enthusiast that I am, I took it apart. The LEDs from the circuit were very corroded. Looks like the panels boxes absorbed salt water… The Panels looked great and were guaranteed for 25 years… Yeah right…. At aprox $1.20 a watt, they work nicely providing at peak 12v @ 13 amps. In ten years efficiencies will be better. From my experience, use 80-160 watts of solar cells to one 12V battery. My 12yr old Optima Deep cycle battery is still working well! Oh, a final thought, angle your panels for max performance on time of demand. In North America, field day falls in June. So, panels are probably best at latitude 0 to +10 degrees. At my location of NL 41.5, my panels are set at about 50 degrees. I don’t want them to bake with direct summer sunlight, and in the winter months, I get lots of ground reflection. So, I worked for a happy medium. Currently, I have all the power to run my laptop, IC-7300 @ 5-50 watts, and a couple of qrp rigs for 6-8 hours.
-Mike
KD0ZW