An anonymous reader quotes a report from The Telegraph: A new type of battery that lasts for days with only a few seconds' charge has been created by researchers at the University of Central Florida. The high-powered battery is packed with supercapacitors that can store a large amount of energy. It looks like a thin piece of flexible metal that is about the size of a finger nail and could be used in phones, electric vehicles and wearables, according to the researchers. As well as storing a lot of energy rapidly, the small battery can be recharged more than 30,000 times. Normal lithium-ion batteries begin to tire within a few hundred charges. They typically last between 300 to 500 full charge and drain cycles before dropping to 70 per cent of their original capacity. To date supercapacitors weren't used to make batteries as they'd have to be much larger than those currently available. But the Florida researchers have overcome this hurdle by making their supercapacitors with tiny wires that are a nanometer thick. Coated with a high energy shell, the core of the wires is highly conductive to allow for super fast charging. The battery isn't yet ready to be used in consumer devices, the researchers said, but it shows a significant step forward in a tired technology.