I've been using this GR-8900A since middle school (10y ago). No battery replacement or maintenance done so far. Keeps working without any complaints. Did anyone here replace a solar powered rechargeable battery
How to Change a G-SHOCK Watch Battery - YouTube
South Store /Battery Replaced/Box Casio Dw-8400Y-9T G-Shock Madman Men Inn | eBay
Casio G-Shock MUDMAN 3031 G-9000MS - YouTube
Casio G-Shock Mudman GW-9500 Tough Solar - Military Green GW-9500-3ER - First Class Watches™ USA