shake flashlight

Oops, the power just went out and you cannot see a thing. Now what? Try to remember where you left the flashlight and stumble your way around the house to find it. Pick it up expecting to illuminate the room and click... nothing happens. That's right, the batteries died a while back and you forgot to buy new ones.
Sound familiar? For many of us, it does. But it never has to happen that way again. Thanks to a very old principle combined with new technology, now you can have a flashlight that never needs new batteries. That's right -- a batteryless flashlight! Called Faraday flashlights, or more commonly shake flashlights, they work using the principle of electromagnetic induction. It sounds complicated, but in practice it's really kind of simple. Shake it up and you have light for several minutes. If the light gets dim before the power comes back on, just shake it up again. It's that easy.