I've heard the palm-pixi charging stand (which can be easily hacked to charge many other cell phones[1]) gets roughly 70% efficiency. [1] http://hackaday.com/2

I've heard the palm-pixi charging stand (which can be easily hacked to charge many other cell phones[1]) gets roughly 70% efficiency. [1] http://hackaday.com/2013/06/19/adding-wireless-charging-to-any-phone/ http://hackaday.com/2013/06/19/adding-wireless-charging-to-a...