Dear Engineer: How do batteries work? 1

If you’ve got an engineering-related question, chances are we can probably answer it.

Dear Engineer,

How does a battery work? Engineers know the question to that right?


Kid in the College of Arts and Sciences


Dear Kid in the College of Arts and Sciences,

Batteries vary in type, but the fundamental notion is that it is a device store electrical energy in the form of chemical energy, and then transforms that energy into what we know as electricity. You cannot catch and store electricity, but you can store electrical energy in the chemicals inside a battery.

There are three key components of a battery: two terminals made of different chemicals (predictably metals), the anode and the cathode; and the electrolyte, which divides these terminals. Acting as a chemical medium, the electrolyte allows the flow of an electrical charge between the cathode and anode. When a low-current draining device is connected to a battery—like a watch—chemical reactions occur on the electrodes that create a flow of electrical energy to the device.

A disposable battery will produce electricity until it runs out of reactants. These kinds of batteries only operate in one direction, converting chemical energy into electrical energy. Rechargeable batteries (like the ones found in cell phones) can reverse their reaction. Rechargeable batteries (like the kind in your cellphone) are devised so that electrical energy from an outside source (a wall outlet) can be applied to the chemical system, and reverse its operation, restoring the battery to a full charge.

There are various factors that make batteries different from one another from their cell type (wet cell, dry cell) to the kind of metals (lithium, alkaline) that are utilized inside them.

Did you know that the very first battery (called the “voltaic pile“) was created in 1800 by Alessandro Volta?

Go explore!

- The Engineer

About Filmon Merid

Filmon Merid spends half his life in a wood shop, would like to live on a boat one day, and hates cherries and cherry flavored products. He is currently working on getting a computer science degree, but will attend school forever.

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