He emphasized that before cost and performance of electric vehicle batteries come safety, reliability and durability, which will take time to establish. One battery fire of sufficient seriousness to reach major media would have, he said, "very significant negative impact." Everyone, of course, remembers the laptop computers of a few years ago whose lithium-ion batteries caught fire when they overheated. Li-ion batteries large enough to power cars or motorcycles are a thousand or more times the size of those found in laptops, and their cooling issues can be serious. This requires that battery makers be extremely cautious in preparing for this market—while forecasts of billion-dollar business drive a rush to become part of it. Let's hope they get the balance between caution and speed right.