I have 1 year with a precision 3510 with 16 GB, I know it could be expanded but I haven't required it, it has worked quite well until now with the plus that it

I have 1 year with a precision 3510 with 16 GB, I know it could be expanded but I haven't required it, it has worked quite well until now with the plus that it is ubuntu certified, running ubuntu 16.04 and it works quite well, another point is that I bought it with the biggest battery and when I tried using just the browser, the battery lasted around 10 hours, using all of my software for my daily work, the battery should last more than 6 hours if I'm not running CPU intensive tasks.