Richard and Jonny find out all there is to know about batteries - from standard batteries to those powered by seawater, fruit and even…urine. Then they hit the racetrack to witness a world record land-speed attempt by a battery-powered milk float. Will it beat the current record of 73.39mph? Did you know that Nazi scientists created and marketed radioactive toothpaste? Or that it’s possible to make your own toothpaste? Richard experiments. Finally, Jonny slices open a cricket ball and we go behind-the-scenes at a tea manufacturer where each minute 2000 teabags are made.