ROBERT CARDIN. Lenovo’s ThinkPad X240 looks thick only next to wafer-thin notebooks like Lenovo’s ThinkPad X1 Carbon. This machine is only 0.79 inches thick and it weighs three pounds.

The ThinkPad X240 is one of several laptops with Lenovo's Power Bridge technology. The notebook has a 3-cell internal battery and a battery bay on the bottom that accepts either another 3-cell ...