The sprout battery was created by The Big Bang UK Young Scientists & Engineers Fair using five power cells, each holding 200 sprouts, producing 63 volts from the 1,000 Brussels sprouts (this comes into the extra low voltage category – like a telephone – and is safe to touch). Copper and Zinc electrodes are placed in each Brussels sprout to create a chemical reaction between the electrodes, generating a current which can be stored and used to power the LEDs on the tree. The power is stored in a capacitor and released through 100 high efficiency LEDs.