[citation][nom]weirdguy99[/nom]I've had this technology in my torch for over 3 years now..what is with Tom's and old news.[/citation]
I thought of that too.. Except the batteries built in those devices are SO BAD! I trashed two of those torches because they wouldn't hold charge anymore after like a year. So much for environment friendliness...
Now I hope Brother came with a design that will last longer than that!
[citation][nom]mgilbert[/nom]Uh, sorry... To be self sustaining would require greater than 100% efficiency, which is impossible.[/citation]
It gets power from the outside world in the form of kinetic energy (shaking) so it does not need to be 100% efficient. It would only need to be 100% efficient if it was both the source of energy for the shaking and the consumer of the energy from the shaking. Since the source of the shaking to recharge it is presumably from external sources it will work.
These aren't really "batteries" so much as supercapacitors, which take a charge much more readily without the need for high voltages or monitored currents. Makes it easy to recharge them with weak, sporadic bursts of energy from an inductor.
Unfortunately even supercaps have an energy density that's at least an order of magnitude lower than even NiCads. Think of those flashlights everyone's talking about: to power a single white LED for a few minutes requires a solid minute of rigorous shaking. I have a hard time thinking that these inductor/capacitor units could power modern gadgetry for a significant length of time unless they're being constantly jostled. Might be good to run your sport FM/MP3 player while jogging, though.
Great for cell phones - always enough power for one more important/emergency call. Also great for stuff you use so infrequently that the batteries are dead by the time you need it - like the flashlights that are already available.
I don't think that these would generate enough power to be useful for a cellphone, at least not with current technology. But as mentioned in the article, very low power hand held devices like garage door openers, keychain LEDs, etc could be possible.
The problem is that regular batteries used in those devices already last a long time (the remote batteries that came with my last TV outlived the TV) and if these are a lot more expensive, people likely won't buy them.