Buch
Sr Member
Most likely that's what they used. Runs off an EL inverter though, don't think tiny coin batts will work.
this one is about 4" sq.
https://www.sparkfun.com/products/10799
Edit: there's this.
https://www.adafruit.com/product/1350
Nice! Both gadgets are fairly cheap, so it wouldn't be a big loss to just try it out... the panel would have to be cut down, but it seems that's possible if you seal the edges again...
Then we just need the graphics, the badge and a suitable wallet