A battery that can charge in under 30 seconds has been shown off at a technology conference in Tel Aviv. Israeli start-up StoreDot displayed the device - made of biological structures - at Microsoft's Think Next Conference. A Samsung S4 smartphone went from a dead battery to full power in 26 seconds in the demonstration. The battery is currently only a prototype and the firm predicts it will take three years to become a commercially viable product. In the demonstration, a battery pack the size of a cigarette packet was attached to a smartphone. "We think we can integrate a battery into a smartphone within a year and have a commercially ready device in three years," founder Dr Dorn Myersdorf told the BBC.