If your motor KV is setup for a 4c battery inserting a 5c may not work all that well.  Besides switching from a 4c 3300 to a 5c 3300 battery wouldn't the 5c battery weigh more.   A better choice might be a  higher capacity 4c battery.

Besides what kind of a setup are you running and how much time are you looking for.  4c 3300 is a common setup that gives plenty of run time to do the full pattern.

Thanks for the replies. After ordering 4  5s 3300 batteries I found that my charger wasn't consistently charging on each of it's 3 of 4 stations. One station crapped out a few years ago. I've been checking voltage and re charging before a flying session making sure the voltage is in the 16.93 to 16.95V or higher on each battery. 4s 3300 units. So far no more sagging near the end of the flight. I always find the cure after I order the fix.

Perry,
You didn't list your set-up but sounds like it is a full size stunter to use 4s-3300 pack. The charge issue you indicated is something you really want to get resolved. The charger is the one piece of the electric package that can caused you expensive even life changing experiences (like burning down a house). It is the only piece of equipment you need to by the "BEST". Over charging LIPO's is the problem they had in the beginning when they charged them like they were NiCads. A top brand charger is intelligent and stops charging once a safe full charge is reached and also monitors and balances the cells to prevent over charging any one cell.

That said, if you are running a little short on battery headroom a couple tricks can help. One easy change is to reduce the prop diameter 1/4 -1/2". Also make sure the tips of the prop are very smooth. Diameter is an amp eater.

The other trick is to increase the pitch a bit and lower the rpm to keep the same lap time. RPM is the second amp eater. 

Best,          DennisT