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 #
9 Cell 29++ Battery for Lenovo ThinkPad X220 X220i
Laptop Battery for IBM Thinkpad X220 X230 X220s X220I 42t4867 42t4866 42t4865 42t4863 42t4862 - China Rechargeable Batteries and Lithiom Batteries price | Made-in-China.com