In a world gone portable, batteries are key. without those unassuming little power supplies to run our laptops, cell phones and personal digital assistants, we might as well return to the days of paper and pigeons. For as much as batteries offer, though, they still annoy us with their frequent need for recharging or replacement altogether. Lately, the zinc-air battery has been turning up as a new choice of power for handheld electronics, providing up to three times the energy of common alkaline batteries in a more compact package.

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