Finally, we now know the answer to an age-old question: can a bunch of lemons replace a car battery?
Many of you might remember a certain grade school science experiment that shows the awesome power contained within a single lemon. Or, more accurately, the power stored within a zinc nail, copper wire, and the electrolyte solution inside a lemon.
The lemon battery is a very simple device. First, you insert a zinc nail into the lemon and then connect it to a copper wire inserted somewhere else on the same lemon. The zinc oxidizes inside the lemon, releasing positively-charged zinc ions into the lemon, and electrons into the copper, where they combine with hydrogen to form hydrogen gas. The traveling electrons mean a small current is produced which can actually be used to power things.
In science class, lemon batteries typically don’t power much: usually a small LED light bulb. But what if you had a whole BUNCH of lemons all connected together? Would it produce enough power to replace a lead car battery?
To find out, Russian gearhead Garage 54 went to the grocery store and bought a whole bunch of lemons. Then, they cut one open and saw how much voltage each one produced. To start a car, you’d need at least 12 volts and around 400 amps. Each lemon produced just under one volt and a tiny amount of microamps (that’s one-millionth of an amp).
This is a problem. With such low amperage, the lemon battery is basically doomed to failure even with the 1,000 lemon halves that Garage 54 connected up on the floor. Worse, the oxidation reaction of the zinc tends to finish after 30-40 minutes, so they have to get every lemon hooked up in less time than it takes to watch the final episode of Game of Thrones.
They did the math, and found out to actually get a car to work would require roughly 32 million lemons, which would weigh over 5,000 tons. Which seems like a lot, but electric cars had a similar problem with lithium-ion batteries and they overcame that problem eventually. Maybe it's just a matter of time before we're all driving lemon-powered cars?