Thinkpad T510 6-Cell vs. 9-Cell Battery

[albertwu]

For a Thinkpad T510 with 128gb SSD, i5-540 processor, nvidia 3100m 512 mb discrete graphics, and 4 gb RAM, does a 6-cell battery cut it? How much time should I expect with a 6-cell and with a 9-cell battery? Also, by how much does the 9-cell protrude past the back of the laptop?

[awjc11]

I have a 6 cell with my T510 and I'd say for normal usage (browsing internet on youtube, watching some news clips, reading email, surfing the net and stuff) the usual time I get on performance setting is around 2 hours.  If intend to take this out and use it for a day, 2 hours certainly won't cut it. 

[albertwu]

Thanks! By the way, do you use discrete or integrated graphics?