The integration of solar power into my life began with a small $20 investment...a solar battery charger. This small photovoltaic panel charges 2 AA batteries with free green energy from the sun. It also has a USB power-out port and comes with several USB connectors. However, the two 1.5 watt batteries didn't have enough juice to power my 5-watt iPhone 4. But, I primarily use the batteries to power the wireless mice and keyboards in my office...and that works great. Watch the video for the details. Buy the charger in our store.