"<a href=""https://www.youtube.com/watch?v=5uz6xOFWi4A&amp;t=3m15s"">3:15</a> GCSE physics this year had this as a question; using electronic car batteries to keep supply matching demand. Saw the question and thought instantly of this video", thanks Tom! Got a grade 9 which I wouldn’t have got without this video, thanks Tom!