Our Volt has been stored in the Detroit area since January 3rd. GM told me to depleate the high voltage battery to the CS mode state of charge. They also wanted me to either disconnect or trickle charge the 12 volt battery. I have a friend that charges our 12 volt battery for about 20 minutes / week. Last winter our dealer had our Volt on display all winter with the 12 volt battery disconnected. The only problem was getting to the battery to re-connect it as the trunk latch is a 12 volt solenoid. We spend winter living on our boat in Florida so we will be repeating this program every year. We drove our Chrysler mini-van to Florida as we need much more room than our Volt can provide. We do miss the car now.