How to replace battery in Casio Digital Watch W-753 - Casio Digital Watch Battery Replacement - YouTube
Amazon.com: Casio LED Illuminator 10-Year Battery Men's Digital Sports Watch Lap Memory 60 100 M Water Resistant Model: WS-1400H-3AV, Black (WS1400H-3AV) : Clothing, Shoes & Jewelry
My brother's watch lasted a decade on the original battery, and these batteries are tiny, so I'm just wondering.... how long with a big enough battery could one last? : r/casio