They believe a mobile phone sized battery (as in to power a mobile) would be able to turn your car over!
http://www.bbc.co.uk/news/technology-22191650
http://www.bbc.co.uk/news/technology-22191650
Another pipe dreamROSS said:Wonder if this will turn out like the battery they said you could roll up like a tobacco pouch. That vanished without a commercial application.