Updated: 07/07/2020 by Computer Hope

A battery is a hardware component that supplies power to a device, enabling that device to work without a power cord. Batteries are often capable of powering a laptop computer for several hours depending on how much power it requires. Today, many high-end devices like computer laptops and cell phones use rechargeable batteries that allow a user to recharge the battery when depleted of energy. The picture below is an example of a laptop battery with a close-up of the battery rating.

Laptop computer battery

Computer batteries

There are three computer battery types used with computers. First is the backup battery, which is commonly called the CMOS battery that holds your computer's settings, such as the time and date. Without a CMOS battery, you would have to reset the time, date, and other system settings each time the computer starts.

Second, the bridge battery is only found in portable computers as a temporary backup for the main battery. A bridge battery lets you remove the main battery and replace it with a good battery without having to turn off the computer.

Third, the main battery in portable computers is an alternate source of energy for when the computer is not connected to a wall outlet.

Battery technologies

There are different battery technologies that allow a battery to work. Below is a list of some major types you're most likely to encounter.

Battery backup, Battery terms, Phone terms, UPS