I really need some help here. I 2010 supercharged RT. I garage it. and dont use it every day some times not for a week or 2. I am having battery issues. it will die on me within a week of it sitting and its only a year old. I bought a 900 volt jump starter but it wont jump the car. I know it could be a bad battery. any ideas of how to keep it charged while the car is sitting? I dont have an outlet in the garage.