There is always a small drain on a road car, the alternator takes a small amount and any alarm system like wise.
However, it should not be an issue as both should be small drains and the car should start normally after being left for at least a fortnight.
I'd check with a dealer to make sure there is no proceedure to be done when changing a battery, and then without turning anything on, put my meter in the path and measure the current drawn when the car is turned off.
