Floaty! on Twitter: "So last night I tried to take apart my own PS2 slim (SCPH-77004). All I needed to know was where the heck the CR2032 battery was placed in (dusty
PlayStation 2 Slimline Clock Battery Replacement - iFixit Repair Guide
Emerson PowerSure PSI PS2-72VBATT 12V 9Ah UPS Battery - This Is an AJC Brand Replacement - Walmart.com
Probably the most convenient place for the clock battery : r/ps2
Guitar Hero React Legacy Brown Battery Cover Playstation 2 PS2 RT696P | eBay
Will any old CR2032 battery work as the PS2 clock battery? : r/ps2
PlayStation 2 Slimline CMOS Battery Replacement - iFixit Repair Guide