Amazon.com: Compatible for Lenovo IBM ThinkPad P50S P50 P70 P51S P51 P71 P1 P52S Fits for Yoga P40 Replacement BIOS CMOS Battery : Electronics
Synergy Digital CMOS/BIOS Battery, Works with IBM Thinkpad W500 CMOS/BIOS, (Li-Ion, 3V, 200 mAh) Ultra High Capacity, Compatible with Evesham 02K6541 Battery - Walmart.com