During a storm last week we lost all electric power. Temperature about 20 deg. (F) Volt was in garage, charging with 115v. Next day, with house power restored, I disconnected Volt charging cable to do an errand. Many error messages, headlights on but dim and then everything totally dark. Gear shift frozen. I jump started it (using battery terminals in trunk) but car would not move. I was able to move gear shift to Neutral so car would roll. Called for tow to dealer who replaced 12v. battery ($400 for diagnosis, battery and charge). My question: what actions should I take on Volt when we have a storm power outage?