Lenovo ThinkPad 9 Cell Lithium Ion Battery 44++ ( Manufacturers P/N; 0A36307 ) 94Wh Extended Life System Battery For X220 And X230 Laptops Only : Electronics - Amazon.com
0A36306 IBM Lenovo 6-Cell Battery 44 for ThinkPad X220 X230 (Refurbished)
Replacement Battery for Lenovo ThinkPad 45N1023 - DISCOUNT ELECTRONICS
Amazon.com: Lenovo 6 Cell Battery 44+ ( 0a36306 ) For X220 And X230 Laptop In The Factory Sealed Lenovo Retail Packaging : Electronics
New GHU Battery Lenovo ThinkPad Battery 44+ Plus (6 Cell) Compatible with X230, X220 (0A36306)
I put the Lenovo ThinkPad X220's 24-hour battery claim to the test | Windows Experience Blog