This was derived from the Sphere thing which I'd designed.
Designed a LED holder to attach 2x LED to a CR2016 button battery.
Print using clear or translucent PLA.
You'll also need:
2x LED (trim the LED leads to about 10mm, keep one shorter to indicate the negative polarity)
1x CR2016 button battery
Use the "+" and "-" sign on the Sphere_int_LED_V2.stl for assembling the parts correctly.
There are 4x grooves for the LED leads, use a pair for each LED.
For storage purpose, remove and place each LED into the "+" and "-" sign. The battery can be left in it's compartment :)