Solar panels are devices that convert light into electricity.
They are called "solar" panels because most of the time, the most
powerful source of light available is the Sun, called Sol by astronomers. Some
scientists call them photovoltaics which means, basically, "light-electricity."
A solar panel is a collection of solar cells. Lots of
small solar cells spread over a large area can work together to provide enough
power to be useful. The more light that hits a cell, the more electricity it
All the VESTPAK™ models have USB cable connectivity "thru" the backpack from any solar panel you may choose. So that all your devices are recharging inside the backpack.