How do flashlights without batteries work?

Dear student,

The light works because it's manually charged by shaking or winding up the small dynamo generator that runs the flashlight.

For example, a shake flashlight requires you to shake it up for a few seconds to a minute. The longer you shake it, the longer it stays lit. If it begins losing its charge, simply shake it some more.

Squeeze models work the same way. Squeeze it several times and you have light for 10-15 minutes.

The least expensive of the no battery flashlights are the wind up types, but they work just as well.

Another important feature is that most of these flashlights have an LED bulb. Why is this important? Because LED bulbs have no filament that burns out and they don't require the high power that a battery flashlight does. In fact, an LED bulb will last upwards of 10,000 hours.

Team

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