Battery case for LED letters

Battery case for LED lettersfor linked LED letters with heart. There are enough space for a double 18650 socket, switch and Microcontroller. 

Overal lenght of the letters: 255mm.

Here are the original parts

https://www.prusaprinters.org/de/prints/109865-glowing-wled-or-led-all-alphabet-letters-and-all-n

https://www.prusaprinters.org/de/prints/110668-glowing-wled-or-led-hearth