The lenovo thinkpad x240 typically uses a 6-cell lithium-ion battery with a capacity of 58wh and a voltage of 11.4v. capacities like 5200mah or 58wv. the x240 also supports a 6-cell battery
here's a more detailed breakdown:
battery type: lithium-ion
cell count: 6-cell
voltage: 11.4v
part numbers: 45n1126, 45n1127, 45n1124, 45n1125, 45n1775, 45n1776, 45n1777, 45n1136, 45n1738, 45n1128, 45n1767
compatibility: compatible with other thinkpad models like x240s, x250, x260, x270, t440, t440s, t450, t450s, t460, t460p, t470p, t550, t560, p50s, w550s, w550, l450, l460, l470, k2450, s440, and s540