Question about macbook pro battery

[JordanLB23]

http://store.apple.com/ca/product/MA348LL/A

i bought that and im going off the university.

my current batter lasts like 1hr 30-2 hrs im guessing, but it wont be enough for a whole day i think so i bought that.

can i use the above as a backup battery? like charge both, then when my 1st one runs out, i just switch it out midway through class?

 

[S.B.G]

Yes, but you have will have to power off while switching batteries of course.