This simple hack save planet :D or maybe your wallet ....
- It is just small round piece of board
- micro USB for delivery power
- 3V regulator
- alligator clip holes for your multimeter to measure curent
- single board with micro usb is CR2016 =1.6mm + adapter is CR2032 = 3.2mm ... EASY ?????I
understand is not like real CR2032 but I believe that help with development battery operated devices.
For sale in my store: https://www.tindie.com/products/bobricius/coin-cell-battery-emulator-cr2016cr2032/