Batteries are important to future transportation, but there has been a single-minded focus on them for too long, says professor of history David Hirsch: "Batteries are only one piece of a complex suite of long-term solutions to the problem of over-reliance on internal combustion. Yet too often the public debate begins and ends with groups of scientists and engineers praising the super-battery of the future and other groups, often economists or incumbent vehicle manufacturers, talking about the liabilities of the battery of today."