Amazon.com: VINTRONS Replacement Battery for IBM ThinkPad R31, (200mAh / 0.6Wh), : Electronics
Amazon.com: Synergy Digital CMOS/BIOS Battery, Works with IBM ThinkPad A31 CMOS/BIOS, (Li-Ion, 3V, 200 mAh) Ultra High Capacity, Compatible with Evesham 02K6541 Battery : Electronics