Does battery size matter?
 

It depends on what the motor and ESC are rated for, some you just just plug up the 4s and fly, some you burn up components.

Check the specs on the motor

Thanks Barracuda hockey. I will try to sort that out but not sure what I'm looking for on the motor and ESC.

Find the part number for the engine, its usually in the spares list in the manual, then ask the Google God.
Heres an example, an EFlite Power 15 brushless
https://www.motionrc.com/products/e-...er-motor-950kv

Scroll down and you will see its good for 3s or 4s under input voltage.

The voltage itself is not so much the issue, it is the combination of the battery, motor,and prop that determine peak current draw. Too much current draw and you will fry something. The higher the voltage the faster the motor will want to spin, meaning, you often need to go down in prop size (and/or pitch) to keep from drawing too much current (at max throttle).

Best way to check is to use something like ecalc (https://ecalc.ch/motorcalc.php) to see how it will behave. Plug in battery size, ESC rating, motor, and prop size and it will spit out the estimated current draw (along with a whole bunch of other stuff) and tell you if you are likely to burn out something.