Synergy Digital CMOS/BIOS Battery, Works with Dell Precision M4400 CMOS/BIOS, (Li-Ion, 3V, 200 mAh) Ultra High Capacity, Compatible with Acer 23.22207.041 Battery - Walmart.com
Amazon.com: Rome Tech CR2032 CMOS Battery for HP ProBook 645 G1 650 G1 Elitebook 840 G1 Dell Vostro 5502 - Laptop Backup BIOS RTC 3V CR 2032 Battery with 2 Wire Medium Cable Long Connector (1-Pack) : Electronics