I use the Dell Inspiron 15r 5520 model laptop and i want to replace the battery. It cuurently works with a 4 Cell battery but I want to replace it with a 6 cell battery. Is it possible to do so ? Else does it affect the system negatively?
It will increase the weight of the system of course, but otherwise won't be a problem. There is also a 9-cell battery for this model -- that said, that one doesn't fit entirely inside the system (it sticks out the back of the system) so it will also increase the size of the system.
You're better off with OEM batteries than with third-party knockoffs.