Originally posted by sonhouse
A very badly written piece. I don't even think the title is correct. The battery does not charge itself, but is charged via mechanical energy instead of electricity.
Then they tested it by sticking it on someone's shoe and compared it with a similar device with separate charger and battery (presumably also on someone's shoe) - hardly the most scientific of methods.
No mention of how much power is put in or how much is lost in the generation stage and how much is lost in the charging stage (in the separate device).
But then again, if it works, lets go ahead and make them and do the science later.