Lenovo ThinkPad tablet battery 67+ 6 Cell for X230 0A36317
Lenovo ThinkPad 9 Cell Lithium Ion Battery 44++ ( Manufacturers P/N; 0A36307 ) 94Wh Extended Life System Battery For X220 And X230 Laptops Only - Walmart.com
X230 6-cell battery re-celling considerations, 30+ and 44+ battery info [includes pictures] - Thinkpads Forum