SolarMonkey Bike?

I received a SolarMonkey Adventurer - Portable Solar Charger with Internal Battery for the holidays and am trying to figure out how to hook it up to my bike lights live. Thus far, I can top off my cell phone after a few hours of charging the monkey, but I do that in the evening when not in use. Pretty cool stuff, but it does not have a gauge to know how charged up it is. It says it takes 12 hours of sun to fully charge it, and I have only received a full charge by plugging it into the wall. We'll see what I can do! As Spring approaches, the sun should be more available for charges. Next will be a solar charging station in our home!