Is it my computer or charger the problem?

[whatsherface]

So, when I plug the charger into my computer, I have to hold it a certain way to get it to charge.  But I don't want to buy a new charger if maybe something is wrong with my computer.  Is there a way to check to see if the charger is the problem(which I think that it is the charger)?  Also, my battery isn't holding much life lately.  I have had the same battery since I got the computer two years ago.  Should I buy a new battery too?

[Raptor]

Most likely the system board charger pin that has gotten loose and needs resoldering. Common problem with many laptops. What brand is it?

Batteries do not last forever, 2 years of usage is quite some time.

You'll have to get it repaired and order a new battery. That'll probably cost more than buying a new laptop, though.

[whatsherface]

That sucks.   
If I take it to a computer repair place, could they find out right away, like not taking it apart to figure out the problem?