Dynamo flashlights

"I need a flashlight, quick! Oh $%&, the batteries are dead!! what now??"

Wouldn't it be great to be able to charge the batteries on the spot, almost instantly?...

Well, that is possible right now!
Today's technology allows to build efficient dynamo flashlights, which do not consume high energy due to LED's

There are 3 kinds of dynamo battery flashlights:
Shake, crank, winding.

I tried all three. They have a small rechargeable battery, which you must charge on the spot.
The first one works on the concept of changing magnetic field creating an electric field, the other two on motor-generator.

Shaking

 The shaking concept is interesting, but it is very tiring. Apparently it hasn't got as much efficiency as the other 2. Additionally, the movement has a high wearout of the materials, since we are moving a weight

back and forth inside the flashlight. The stoppers will wear-out.
Also the magnet inside is very powerful - NeoDyme - which have negative influence on electric and electronic equipment.
One of the commercial problems which occurred with these flashlight is the price: too high. "Made in China" products showed the consequences: instead of a rechargeable battery + a powerful magnet, many flashlights came with normal non-rechargeable batteries, and only an iron clump! Total rip-off - but only when you most needed it!

Wind-up

Wind-up is my favorite system. I have one in my suitcase, one next to the fuse box at home, another in the car..
Using LED technology, some also have some flashing integrated for emergency signalling or for cycling on road.
The one I have in my car has also a cable that allows you to charge your mobile phone.
I tested it with my Nokia and it works, although it might take over an hour to get some charge.

Cranking

It uses the same concept as wind-up.
The main disadvantage of cranking is that you get quickly tired of pressing with your hand.

The market already chose the favorite one: winding!


Beside the ecological concept that you will not abuse on mother nature, I like them primarily because they are always ready for action!
You can leave them anywhere, and forget about them. When you need them, just wind up for a minute, and you will have light for some minutes.

Never spent money on batteries for flashlights again!