Step 3: Building Part 2 - Soldering Leads to the Back Side
On the back side of the solar cells, the side not facing the sun, the soldering process was easier because there was no white coating to be scraped off. Instead, there were small areas where leads are meant to be soldered to.
To solder leads to the back of the cells, I again applied solder to the solar cell ribbon wire, and then held it to the rectangular area where leads are meant to be soldered to, and pressed the wire down to the rectangle with the soldering iron.
I then snipped the solar cell ribbon wire short like the other lead, to be able to use less of the solar cell wire.
I finally soldered some wires to the solar cell wire attached to the cells, and put some hot glue over the space where the cell ends and the ribbon wire begins, to insulate and strengthen it.
I tested the output of each cell with a multimeter to see what I was getting. I also connected some cells up to LEDs and a few small motors to test my output. These tests were done to determine how I should combine the cells in series and parallel to get the right amount of volts and amperage for my application. I ended up deciding to connect them all in series, as my output was fairly disappointing.
At this point in the process I started to have problems with cells breaking, as they are literally paper thin, and break very very easily. I managed to put some back together, making sure to align all the thin white lines on the front side of the cells together and taping/hot gluing them in place.