9 Cells 44++ Battery for IBM Lenovo Thinkpad X220 X220i 45N1027 X220s 42T4862 US | eBay
Amazon.com: Lenovo ThinkPad 9 Cell Lithium Ion Battery 44++ ( Manufacturers P/N; 0A36307 ) 94Wh Extended Life System Battery For X220 And X230 Laptops Only : Electronics
9 Cells 44++ Battery for IBM Lenovo Thinkpad X220 X220i 45N1027 X220s 42T4862 US | eBay
Lenovo Unboxed: ThinkPad X220t tablet - YouTube
Lenovo's X220 ThinkPad with '24 Hour' Battery | WIRED
Lenovo ThinkPad X220 Review
Lenovo ThinkPad X220 Hands On, Details, Specs And Video
Lenovo ThinkPad X220 really does get 20+ hours of battery life (sort of) - Liliputing
Lenovo ThinkPad X220 review
facelessloser on Twitter: "Not surprising but adding a 9 cell battery to my thinkpad x220 made it quite a bit heavier. Hope its better battery life then my old aging battery #ThinkPadX220 #