I've found some resources online about building your own solar panels. The basic premise I've found is this: solar cells -> diode -> battery -> inverter -> mocha machine First off, if anyone has done this before, any general advice would be appreciated. More specifically, I need someone to point me in the direction of how the amount of power required to charge, say, a car battery is quantified. Meaning, if I have a panel that produces 60W at 18V, how do I know how long that will take to charge a 12 volt car battery? What variables are in play? What are the units of measure? etc. Sorry for being vague, but I'm just getting started with this and barely even know the questions to ask.