A Guide to the Process of How Batteries Are Made

We rely on batteries more than we may realize. From prepping for the holidays (are there children’s toys that don’t require batteries?) to starting our cars to interference-free nights of Netflix and chilling, batteries power our lives. Interestingly, our thoughts about batteries tend to stop once we buy the package. But what happens before the batteries hit the shelves? What is the process of how batteries are made? We’ve put together a guide so you can find out.

Choosing a Steel Container

The first step in the battery production process is determining the size of the battery. Battery sizes range from the common AA, AAA, C, or D to vehicle batteries to batteries for industrial machinery. Once the appropriate size is determined, the corresponding steel container is chosen.

Creating Cathode Rings

Next, a skilled battery maker mixes a variety of ingredients, including manganese dioxide, graphite, and electrolyte. They then press the grainy black substance into the cathode rings. Once the battery maker completes this step, they place the cathode rings into the battery’s steel container.

Inserting the Separator

The separator is a rolled-up strip of paper that is sealed on the bottom. Battery makers place this small paper tube in the center of the cathode rings. At this point in the production process, the battery container is still open. This is also the stage where the battery begins its journey across the assembly line.

Adding Electrolyte

The next step in our guide to the process of how batteries are made is the addition of a substance called electrolyte. Electrolyte is a chemical component that enables the electrical charge between the cathode rings and the battery’s anode.

Battery makers pour the electrolyte into the container, and the separator and cathode rings absorb it. The absorption process can take just about 20 minutes to complete.

Creating and Adding Zinc Gel

During the electrolyte absorption process, battery workers blend a special solution of zinc powder and potassium hydroxide. They mix these ingredients until they form a blue gel-like substance. After the workers create the zinc gel and the electrolyte is absorbed, they pour the zinc gel into the inside of the separator tube. This gel is the anode of the battery.

Adding the Seals

Once workers complete the inner workings of the battery, the battery is live, as it can now produce electricity. To prevent a loss in power, workers quickly add seals. The first “seal” is a brass spike, which workers drive into the center of the container. This spike also functions by collecting the battery’s current. The workers add two more seals—a plastic seal and a metal end cap—and officially seal the battery.

Adding the Label

The final step in creating a battery is placing a label on the container. This label includes important information such as the battery type, size, and any pertinent warnings. Most often, people print these labels on loose, heat-sensitive plastic and shrink them to fit securely around the container.

After the completion of the production process, many manufacturers encapsulate industrial batteries with RIM, or reaction-injection molding. Manufacturers choose to take this next step for a variety of reasons. The most common reasons they encapsulate batteries are to increase resistance against shock and corrosion and defend against moisture and corrosion.

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Written by Logan Voss

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