Battery - nolanhergert/EasyLED GitHub Wiki
Initially I wanted standard 18650 cells that could be swapped out, but they are kind of unwieldy. A better solution for some/most people would be an integrated battery.
ESP32-WROOM32 dimensions: 18mmX25mmX3.1mm
Available Dimensions
In multiples of 5mm. Just google them and you can dial in the right mah.
603040 = 6mm thick X 30mm high X 42mm wide
902030 seems like a good one, although it's thick and doesn't extend over the whole board. 502050 is 500mah too. Much longer.