Rather than a laptop with a big battery, you'd be looking for a small laptop with a tiny screen (screens take up most of the power I would figure).I would think you would have trouble using a laptop for a science degree especially because of diagrams/symbols etc. Saying that, I don't do science, so I can't tell you how many people use laptops in class. My advice if you can would just be to wait to you are at uni and then see what works best.
I have a 13" Macbook pro. For my first three years at uni I had a 15" Powerbook which I found too heavy/big to be carrying around (however it would have been heavier then current 15" laptops). If you are buying a laptop for university, unless your university has updated its rooms to include heaps of powerpoints, I would also try and get a laptop with as best a battery as possible - powerpoints can be hard to find, and if everyone else is using laptops, it makes it even more difficult! Its also difficult if you have 4-8 hours straight of class...
I use my laptop for my law classes but I didn't for my arts subjects. The rationale is that for law it is much easier to just get down as much as the lecturer is saying and attempting to understand it later (and I type faster than I write, and its easier to understand later). This is particularly important to me for law subjects which aren't recorded and/or have no powerpoints (or they aren't put online after the class). On the other hand, I didn't use my laptop in history classes because getting every single word the lecturer said wasn't as important- it was more about themes, and generally the entire course wouldn't end up being assessed (and practically no one else used laptops in arts...)
As a random observation, at usyd i would say between 95-99% of students use laptops in law classes, but only maybe 5-10% use them arts (history in any case). The number of laptops being used however has definitely been increasing since I've been at uni the past 5 years...
Why pay $1.5k for a gaming laptop that's retarded gaming laptops are retarded don't buy a gaming laptop. Quick I need to play 50 minutes of BFBC2 at uni because I don't want to pay for a top of the line desktop that'll be 3 times more powerful and better at the same price.If you want a small, extremely light weight 13" laptop for carrying around uni with an i5/i7 cpu and a powerful graphics card (easily replacing your desktop computer) :
Im typing this from one now.
Lighter than many netbooks yet the latest spec one (not the one in the above link) is still more powerful than the vast majority larger/heavier laptops, powerful enough to run Battlefield:BC2 on the highest settings. Plus you will be the only one at the uni library without a freakin piece of fruit on the back of your laptop.
Yes, they retail for 4k here, but i imported mine from an ebay seller in the US for only about $1.5k last year (new). You will be blown away with this laptop trust me. Very light to carry around too.