Easy ThinkPad X31 repair. New RTC/CMOS battery. : r/thinkpad
100X CMOS BIOS Battery for IBM Thinkpad T20 T21 T22 T23 T30 T60 R40 R50 R51 R52 | eBay
Cameron Sino 200mAh Battery for IBM ThinkPad T22,T23,T30,T40,T41,T42,T43,T510,T520,T530,T60,T61,W500,W520,X30,X300,X31,X32,X400|Smart Accessories| - AliExpress
IBM ThinkPad T30 Processor Replacement - iFixit Repair Guide