I have some small solar cells. On the back it only has 2 pads to sold the wires. I wired it all together(it's 4 cells) on parallel(each rated 5.5v and 60mA) powering an arduino fio with a battery backup of 980mah li-po. The system is working perfectly. It's on for some days already.
Now, the most difficult thing to me is to waterproof these cells. What do you recommend? I'm thinking to use hot silicon on the solder pads and assemble in wood or plastic.