Sounds like a flashlight with a built in dynamo (which has some kind of built in battery or capacitor BTW). Magic not required. It is however a good device for an emergency kit.
It's a small 2 LED flash light and is still on after 16 days with out pushing the handle to say if it has a built-in battery then every time i use
The handle it recharges, how can you explain that?
About built-in battery I'm not sure since before all of this happens every time I wanted to use it it only worked when ever I pushed the handle
And the intensity of the light depended on how fast I could push it.