File talk:Supercapacitors chart.svg

What are the times on the diagram?
Are the times shown, charge times, depletion times? What do they refer to on the diagram, for example does 10 hours refer to both fuel cells and the leftmost field of batteries? Or is it one hour for batteries and 10 hours for fuel cells?

Well, any point on the plane corresponds to the time period of the device's discharge, by the formula (energy density) / (power density). However, the text labels don't line up very well at all on this graphic and are terribly misleading/confusing.