When it comes time to purchase a laptop computer, or even a replacement battery for an existing laptop computer, you may face a choice between getting a 6-cell battery and a 12-cell battery. While the 12-cell battery promises extra capacity, it's important to know the differences between the two types of batteries so that you can judge whether or not the larger battery is worth the extra cost.
How a Laptop Battery Works
To best understand the differences between 6-cell and 12-cell batteries, you should have a basic understanding of how batteries work. A cell is simply a battery in its simplest form. The cell consists of three main parts: an anode and a cathode, which are separated by an electrolyte. In a standard Lithium-Ion battery, a reaction at the anode turns Lithium into a cation, which also creates a free electron. The cations move through the electrolyte to the cathode, while the electrons move through the wire to the cathode, where the ion and electrons will meet up again. Any motor positioned along the wire can use the electrons for power. Batteries are made up of a number of these cells, along with a small control board that ensures the battery is operating safely. Laptop batteries are rechargeable, which simply means that the chemical reaction can be reversed, moving the Lithium atoms back to the anode.
Each cell in a battery can be positioned in a series with, or parallel to, the the other cells. When the cells are aligned in a series, the voltages are added together allowing 3.6 Volt lithium-ion cells to be part of a battery that has a much higher voltage. When the cells are aligned parallel to each other, the voltage isn't added together, but the overall capacity of the battery is increased. Because of this, a 12-cell battery has twice the capacity of a 6-cell battery, while maintaining the same amount of voltage.
Size and Weight Differences
Because the 12-cell battery has six cells that a 6-cell battery does not have, the battery does have some physical differences. First, the 12-cell battery is twice the size of a 6-cell battery, making it bulge out from the bottom of many kinds of laptops. This isn't always a bad thing, as the extra space it creates will help keep the laptop running cooler when you use it on a desk or table. Second, the 12-cell battery will have twice the weight of a 6-cell battery. The battery is normally one of the heaviest components in a laptop, so this consideration should not be taken lightly if you plan on carrying the laptop around.
It takes extra components to create a 12-cell battery, as compared to a 6-cell one, so there is naturally a higher cost associated with the 12-cell battery. Additionally, 12-cell batteries cost more due to the extra capacity being regarded as superior to the 12-cell battery's drawbacks. While prices will vary wildly based on the battery's manufacturer and model, the 12-cell is rarely priced at more than twice the price of the 6-cell, making it a judgement call for the individual whether or not the 12-cell battery is worth the extra cost.