Original laptop battery is not the only choice

Generally, there are three main information on the label of replacement as follows:

Battery fit model: 40Y6799 (Note: according to the official description ThinkPad, 40Y6799 is to use common screen T6/R6 6-cell battery, 40Y6797 is the 9 cell battery);

Battery Type: Li-ion Cell parameters: 10.8V 7200mAh

OEM9 cell battery and original 6 cell battery: