Have a 2005 roadster just purchased in July. Live in PA and have it garaged. It sat for 2 weeks late November and when I attempted to start it it was completely dead. Used a battery charger and it fired up so I went to Pep boys and put a new battery in. Car has now only sat for 5 days and it is dead again with a new battery. Live in PA and temp been in 30's but garage is around 50. Do I have more than a battery problem?