The lemon battery, it’s a perennial kids science favourite and perfect for a rainy Saturday morning (if it’s not raining why aren’t you kids outside playing instead of surfing the Pipes on the InterWebs, huh?) Anyway, with a single lemon, a few bits of wire, a copper penny, and a zinc-galvanized nail you can generate electricity (just over one volt).
However, one lemon is not enough to light an LED or power a pocket calculator, for that you’ll need not only more voltage but a higher current, which means more power – Power (Watts) equals voltage (in Volts) multiplied by current in Amps. Four lemons produce enough power to make an LED glow dimly. But, that low current is probably not going to be enough to power your iPod, which is a higher current device. For that you will need what is called a lithium-ion battery and iPods (other mp3 players are available) usually come with such a battery built in, so there’s no need to worry about carrying a dozen lemons and a bag of nails with you for portable music.
The following video explains the ins and outs, quite literally, of making a lemon battery, it’s very methodical and shows you the precise steps needed even if the narration is a bit stiff.
More science videos from the same labs available here