IBM ThinkPad 2655-27A ThinkPad 560X Thinkpad 570 T Replacement Battery: BatteryClerk.com CMOS Backup
How to remove the Supervisor BIOS password for an IBM ThinkPad - Super User
Synergy Digital CMOS/BIOS Battery, Works with IBM ThinkPad R52 CMOS/BIOS, (Li-Ion, 3V, 200 mAh) Ultra High Capacity, Compatible with Evesham 02K6541 Battery - Walmart.com
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|Digital Batteries| - AliExpress
IBM Thinkpad T40 T41 T42 R50 R52 issue boot start problem freezing does not power up Part 2 - YouTube