Those plates you put your cell phone and mp3 players on that charge them, I get the concept of inductive charging, except for how the hell does it know what voltage to supply to the batt in the device?
+1...lithium cells don't need a big load to charge like lead-acid. They can trickel charge to full overnight for most devices.
It also helps that lithium cells can be charged at a higher rate (%/hour) than any other cell type...I've worked with some cells that can go from empty to full in five minutes or so. Those are special chargers though, and they can get pretty hot.