3 watt, 12 volt polycrystalline solar panel I got off of ebay for around . It only puts out around 170 mah, but that will be boosted when it is wired with two other panels.
Jul 22
The Siemens ST-5 solar panel I purchased off eBay. This is a thin-film panel based on CIS (Copper Indium Selenium) technology Siemens developed in the late 1990's vs the more common amorphous silicon type solar cells. Compared to the amorphous silicon thin film cells, these supposedly would take the heat better and had a higher conversion efficiency; up to 20% was measured in laboratory tests. The Siemens solar division was later bought out by Shell Oil corp in 2002 which continued to produce these until sometime in 2006 when they suddenly discontinued the line (unfortunately). This is the 5 watt version and the smallest one that was available from Siemens. The nominal current rating as listed on the back was 320millamps at 15.6 volts DC (Open circuit was around 20 volts) which was more than enough to charge a cell phone and a iPod. It would also run a radio directly but did not have the "muscle" to operate the CD player portion of the radio. I'm planning to get more of these soon and parallel them to charge the two deep cycle batteries that I have for "12 volt room" so I can finally go "off grid"
