I reviewed another solar charger a few years ago - PowerPlanet - that converts solar energy to store in its NiCd battery and in turn, charges or power any USB devices. It can also be charged with the included adapter. 

This is the new SolarKing DG Power S2, featuring larger solar panels and capable of being charged via solar energy or the included adapter. It is capable of supplying at two different voltage - 5V via USB and 9V via an adapter (included). Also comes with various USB to accessories adapter plugs.

Sliding open the spring-loaded adapter reveals two contact electrodes capable of charging most dSLR batteries, including the one from my Olympus E1.

It keeps its electrical energy in its 1800mAh Lithium-ion battery.

Full charging takes 10-12 hours under direct sunlight and 5 hours using AC adapter.

Size : 166.5mm x 89mm x 17mm

Weight : 190g

It also comes with a built-in white LED, can be used as a small torchlight. You can even check its battery reserve graded over four levels via three green mini-LEDs.