Certainly appears to be a drain from somewhere. BTW, Just because the radio isnt working, does not mean it wont drain power, unkless you removed it. I would suspect a bad battery first. If that passed a load test, then move to charging, make sure the battery is being recharged completely. If these are all good, need to first determine if there is a drain, and if so how much. Most modern cars will have a small drain on the battery built into the power configuration. D/C positive battery terminal, Place a test light between the battery +, and the disconnected + bat terminal. If the light illuminnates, you have a drain on the battery. Now you will want to place an Ammeter in place of the light (Or start withe the ammeter), and see how much it is. It should not be all that much. Certainly not exceed the battery specs. To locate the circuit(s) with the drain, attach the light again, and pull the fuses one by one til the light goes out. Hopefully its not all that many :) To further locate the fault, reinsert them one at a time, if the light goes on pull it back out. at the end, you will have isolated the problem circuits. I would leave any further diagnostics to a technician. They have the tools and resources nedcessary to locate the fault fast. Feel free to email me with questions.

Batteries die if tyhe car is not in use. I had the same issue with a semi brand new. If you decide to leave a car unused for a long period of time its best to at least run your engine once or twice a week. or get one of those solar battery chargers and plug it to the battery .