What I was asking with the voltage question is if you have multiple motors hooked up to one motor controller will the voltage drop or will it just take more amps from the battery as needed per motor?
Yes, and no.
Chances are, as your current consumption goes up, unless you have a good regulated power supply the voltage will drop, how much depend on the current and you voltage source. This happens because all voltage sources have a tiny internal resistance, and because V=IR, the higher the current, the higher the voltage drop across this resistor, and lower the output voltage of the battery.
But, as long as you can supply enough current, the voltage drop would not be insignificant.
For example, if your battery is designed to put out a max of 2A, and you try to use around 2A of current, the voltage will take a plunge. However if you only use 500mA, there still will be a voltage drop, but not enough to matter.