Blue LED Dies Rapidly on 9v Battery but OK on CR2032 Lithium Coin Cell - YouTube
DOACT BT‑168PRO Digital LCD Battery Tester 1.2V‑4.8V Battery Checker For Small Batteries Button Cell Like CR2032\ LR44\ L736\ 6F22 9V\ AAA\ AA\ D\ C And Other Batteries - Walmart.com
File:Batteries comparison 4,5 D C AA AAA AAAA A23 9V CR2032 LR44 matchstick-1.jpeg - Wikimedia Commons