Parasitic draw can be difficult to assess. If your battery is relatively new and believed to be in good condition but still goes dead overnight or after a few days of not driving it, then you should definitely have an experienced car battery specialist or trusted mechanic test it for parasitic draw. Parasitic draw is a load put on a battery when the car is not in use. Meaning everything is doors are closed including glove boxes, trunks and anything that would have a light associated with it when it is open.
Hood lights need to be disabled when testing for parasitic draw. Some luxury cars maintain a load on the battery for a certain amount of time after it is parked and its system shut down, etc. Read the manual for how long or let your car sit for an hour prior to testing it. Key Fobs can also activate systems in a car so leave them away a load put on a battery when the car is not in use. Meaning everything is off, key is out of the ignition all from the car when you do testing.
Parasitic draw troubleshooting can be a tedious time consuming task. Correcting the problem can be tedious as well when electrical diagrams need to be analyzed. The most common method for testing for parasitic draw is to use a voltmeter and pull out fuses one by one until the amperage drops to an acceptable load of