Tiny Solar Panels, and possible uses.

We've ALL seen them: garden lights, powered by little AA batteries, with LEDs for the light source...and little solar cells located somewhere on the outside.  They used to be quite expensive...when they first came out, I remember paying $50 for a box of 4 of them, and giving them to my mother for a Mother's Day gift.  She adored them, as did I.  NOW...at WalMart, you can find them for as little as $1.50...and they come in many shapes and sizes.  Again...all complete with solar panels.


Back to the garden lights...one problem with these lights is that they aren't very well made.  They are made to stick into the ground, and HOPE that nothing hits them, steps on them, or in my case...from when I was still drinking, run them over accidently with your motorcycle.  Because of the latter, I had a SHOEBOX full of these little panels.


Some of the panels had never had the plastic protective cover removed at the time of installation...so the UV light clouded the plastic and burned it on, in turn, rendering the panel useless for what I wished to do with it.  The best five panels were set aside.  (I had a sixth panel, but in February of 2010, while trying to foolishly cut the rubber gasket off, I stabbed my hand with a Ginsu knife...the blade buried itself almost 3 inches into my left hand.  I didn't use that panel...)


To increase the amperage output capability, I wired three of the panels in parallel...all three + leads together, and all three - leads together.  Then, to bump up the voltage, I connected the cluster to the remaining two panels in series...+ to -, and so on.


In full sunlight, this combo gives me approximately 9.5-10 volts at about 350-400 mA of current.  This is MORE than enough to drive a simple charge controller, comprising of an LM317 device and a resistor.  


Yesterday, the sun was blazing and beautiful.  It was a perfect day to test the panel array out.  I added 2 leads of 12 gauge copper with alligator clips to the panel's leads.  Then, I removed the battery pack from my dead Icom 2AT HT.  (By dead...it is in need of having the final amp transistor replaced, but the receive works just fine.)  The clips were connected directly to the posts on the underside of the 2AT...then everything was moved to a black surface in my sideyard.  The 2AT draws less than 30 mA fully squelched, but would the panel be able to drive the RX directly?  A quick QSY to 144.39 (APRS...always busy in FN02ox) and the test began.  Within a second or two, the squelch opened up, and audio came out of the old HT.  I had done it!  I recycled solar cells that mmost anyone else would have sent off to the landfill, and re-purposed them.  Truly, a green project through and through.


These panels are going to be installed as a solar trickle charger in my garage...in order to keep the 20 A/H battery I use for 10 meters and for powering a cigarette lighter socket (for my 12V accessories) charged when I'm not using them.  The LM317 circuit will aid in this pursuit, and with the addition of a couple of diodes, will protect the panels from current flowing back into them.

Give this project a try.  You may just find that you have devices that YOU wish to power directly by Old Sol.