Batteries and storage

The ninth entry is la durata in cicli, and the noun that carries it is wider in Italian than anything English has to set opposite it. La durata is built on durare, to last, and it answers two questions that English keeps firmly apart. The first is how long something goes on: la durata del film, la durata della riunione, la durata del contratto, and there « duration » fits exactly. The second is how long a thing survives before it is used up: la durata della batteria, la durata dello pneumatico, la durata di un utensile — and here « duration » is simply wrong. English reaches for « life » instead, and has built a small family on it: battery life, shelf life, service life, tool life, and the entry on this page, cycle life. So la durata in cicli is cycle life and never cycle duration. The test is short enough to carry about: if the thing wears out rather than finishes, the English word is « life ».