BF4 you will want to run on lower settings and get good enough results. 30fps maybe a bit more depends on what quality you pick. At Low will play it for sure well enough to not be annoying. If you can go past that, will need to try and see how well you like how it plays.
Since you can't upgrade laptops you may want to go up a bit in speed. MANY people make the mistake or picking out something because it's cheap and then get frustrated and ask if you can upgrade the video card or CPU. Look at all the netbooks for sale on craigslist or other low end systems. You don't see a lot of people selling their $800+ laptops but a lot are selling $3-500 systems.