Rechargeable LED lamp - Lemmy.World

I’d like to build a small light that i can use to cast a shadow to a wall. It needs a single led that’s really small and bright and that can be recharged. Also I want to put it in a special casing. However I don’t really know how to build one myself. So I had the I bright idea to take apart a flashlight that is rechargeable, but I’m not sure which one can be dismantled. Do you have any idea what flashlight I could use or what parts I would need?