Solar Power Generator

I'm using a 15 watt solar panel to keep the Powerpack 600 charged. I use it to charge pdas, cell phones, video games. I have also used it for portable power on fans,lights, TVs, and laptops. Will not power frigs and large power hunger items. I purchased the Powerpack 600 to see if it would charge from a solar panel and it charges from sun-up to sun-down. HEY,I'm a little greener than I once was!