Making Fruit Batteries Which One Works Best?

A battery comprises two electrodes, and an electrolyte to keep them apart. Making lemon batteries is a fun experiment. Today we decided to broaden the discussion to using other fruit. We suspect ripe lemons may still prove best as they contain a generous amount of acidic juice. But first, what is the science behind making fruit batteries?

The Science Behind Making Fruit Batteries

We need a galvanized nail and a penny for making fruit batteries. These two items will become the electrodes once we push them partly into the fruit. Now, if we connect these two with a piece of wire through an LED light we will complete the circuit and electricity will flow.

We could also generate electricity through a multi-meter. However, we think seeing an LED light up is more fun than watching readouts on a tiny screen. We can also make several fruit batteries, and connect them in series or parallel to see what happens. However, we would need approximately 6,000,000 lemons to turn an auto starter motor over.

What Other Fruits Could We Use Instead?

We can use several other fruits for making batteries. We could also use their juice in which case the galvanized can could be one of the electrodes. However, we recommend rather using whole fruit, because there is less chance of making a spill in mum’s kitchen.

Any citrus fruit such as lemons, limes, oranges and grapefruit will work because they all contain citric acid for the electrolyte. However sweet, ripe ones are less effective. We have also heard of experiments using apples and pears although these apparently don’t work as well.

Potatoes on the other hand make excellent batteries because they contain phosphoric acid. Indeed, some scientists have suggested using them to power lamps in poor countries where there are no electricity grids. If we boil a potato for eight minutes it works even better. That’s because the starch granules burst and they spill their moisture.

That is the science behind mashed potatoes by the way. However, after extensive tests we can report that lemons are still best for making fruit batteries.

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Preview Image: Apple Battery