Lenovo ThinkPad X230 3435-24U 13-inch Tablet PC (Intel Core i7-3520M processor, 4GB RAM, 500GB Hard Drive, Windows 7 Professional)
Bay Valley Parts®Lenovo 6-Cells 11.1V 5200mAh Hi-Quality Replacement Laptop Battery for THINKPAD X220T,X230T,X220 Tablet,X220I Tablet,X230 Tablet,X230I Tablet Series
$40 and some elbow grease and my x230t now has better battery life than new. : r/thinkpad