In a nutshell, scientists from Southampton University used an alternating current, powered by a transformer, to recreate a bolt of electricity by passing 200,000 volts across an 11-inch gap. This generated the same heat, light and charge produced by a bolt of lighting, which was then used to charge the battery on a Nokia 925 phone.
According to The Daily Mail, „Neil Palmer from the university passed the extremely high voltage across a gap between two conducting tubes in order to generate the bolt. The charge was then passed through a second, controlling transformer, connected to the phone’s battery.
Official Source: http://www.dailymail.co.uk/sciencetech/article-2441940/Scientists-harness-power-electrical-strikes-charge-mobile-phone-seconds.html
http://www.youtube.com/watch?v=RJTl2oqaWPs&feature=player_embedded#t=0
