Tested the 2013 Charger RT Road & Track battery and it read 12.5V. Tested the battery draw while the car was in sleep mode and it read 11 milliamps, which is very acceptable.
I concluded a 4 1/2 year old battery, while still pretty good, can't take 4 days of checking systems readiness. A former Honda and Pontiac service tech recommended locking a keyless start car over moving the key fob proximity to Timbuktu. This places the car in sleep mode quickly. It seems to explain why this car can stand 5 days in an airport parking garage locked vs. 4 days unlocked in my garage.
How much does an original Squarebird clock draw?