Excalibur Electronics makes this great-sounding product called the “Forever Flashlight,” which uses a magnet moving through a coil of wire to produce current (the Faraday principle) that charges an ultracapacitor, which in turn powers an LED.
Great in theory, pretty useless in practise. But ThinkGeek sells them nonetheless, and on their product page, titled “Forever Flashlight,” is this notice: “One-year warranty.”
Thanks for signing in, . Now you can comment. (sign out)
(If you haven't left a comment here before, you may need to be approved by the site owner before your comment will appear. Until then, it won't appear on the entry. Thanks for waiting.)