I noticed that my battery has a bubble wrap like pouch arround it. I found a electrical plug which I assume is for an engine block heater as opposed to a battery heater? I have not been able to find time to trace the electrical plug down. I assume it is for a freeze plug engine heater. So is the bag like thing around the battery to protect it from heat? does everyone else also have one. I never saw one listed in aftermarket parts places.