You need to test it for ignition off draw. Like said in a previous response. A voltmeter or test lamp installed in between the negative cable and the negative battery post. The bulb or meter may show a draw for 30 minutes or so. Depending on radio and USB hub programming. If it doesn't shut down in that time frame it will kill the battery. My job encompasses these type repairs on prototypes at FCA . Sometimes they can be tough to track. If the CAN BUS stays awake the messaging will never shut down. Easy to tell if its the battery. Disconnect it for a few days. Reconnect it. Does it start? If yes you most likely have something pulling the battery down. It may take a scanner to locate the issue. You can try pulling fusses one at a time but it can be a long process. Start with the radio and USB. Most likely suspects. Make sure to trigger the door latch shut if you are testing with the door open.
Doug