Updated: 04/26/2017 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 such as computer laptops and cell phones use rechargeable batteries that allow a user to recharge the battery once depleted of energy. The picture below is an example of what a laptop battery may look like when removed from the laptop, with a close-up of the battery rating.

Laptop computer battery

Computer batteries

There are three computer batteries types used with computers. First, is the backup battery, which is commonly referred to as 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.

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

Finally, 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 listing of some of the major types you're most likely to encounter.

Battery backup, Battery terms, Phone terms, UPS