Introduction: Hack a Trickle Solar Vehicle Charger
Extensive research on small solar systems <5 watts led me to this little inexpensive ($12.99) charger from harbor freight. Sure it is big, but it is also 12V at 1.5 watts and cost less than some 1 watt panels when shipping is included (http://adafruit.com/products/262). it is a 17.5V? open circuit but who wants that awkward voltage? 12V is a nice round number so i kept the trickle circuit and stepdown in.
I took apart the car charger part and did my own little edits to it and made it into a solar source.
The regulating circuit and stepdown were included, the teardown of picture 2/3 was just to show what the car port adapter looked like inside.
I also had the cell in my window powering an LED for a couple weeks......just for fun