Saiful Islam drops a nail through a lithium battery, and explains what it is that causes mobile pho’– how to store energy. Over the course of the lecture, he tackles his toughest challenge yet: trying to work out how to store enough energy to power a mobile phone for a whole year and still fit it in his pocket! With the UK generating nearly twenty times as much energy today as it did 80 years ago, finding better ways to store it is vital for all of our futures. This year celebrates the 80th anniversary of the BBC first broadcasting them on TV. To help mark this occasion, Saiful is joined by former Christmas Lecturers on stage, and repeats and re-imagines some of the most famous experiments and demonstrations. Live experiments include an attempt to break the world-record for the most powerful battery made of lemons and a clear-eyed look at the most energy-packed fuel in the world – hydrogen. Along the way he’ll investigate the chemistry of batteries and tell us what the future of energy has in store for us. Subscribe for regular science videos: http://bit.ly/RiSubscRibe The Ri is on Twitter: http://twitter.com/ri_science and Facebook: http://www.facebook.com/royalinstitution and Tumblr: http://ri-science.tumblr.com/ Our editorial policy: http://www.rigb.org/home/editorial-policy Subscribe for the latest science videos: http://bit.ly/RiNewsletter