Thinkpads Forum

Ideally I would like to see someone do a battery test with the 6 cell plus the optional 3 cell that you can use in place of the optical drive.

Thank you to anyone who can provide such information.

There are many reviews online for the X300 with 6 cell battery. The 3 cell bay battery adds 55% more capacity. Look at the existing tests and multply by 1.55 for a fairly close estimate. Depending on usage you should experience 4hrs (full power maximum brightness) to 10hrs (battery stretch mode) of runtime.