During "The Raft" the kids park the car and leave the radio blaring while they swim out to the raft. As they are killed 1 by 1, "Poncho", the last survivor, is stuck on the raft overnight waiting for the blob to leave. In the morning he tries to outswim the blob and get to shore, and the radio is still blaring. They must be using an Energizer because any other car battery would be dead by this point.