It is known that a battery is generally a collection of electrochemical cells that can help to power an electrical or electronic device. These cells have external connections that would give power to devices like flashlights, mobiles, and even cars. These batteries have two terminals - the positive one being the cathode and the negative one is called the anode. Batteries can be of two types - the primary and the secondary ones. The primary batteries are to be discarded after use and are becoming more and more uncommon due to their disposable nature and the growing concern of the environment. The secondary batteries can be recharged multiple times with the help of an electric current and thus find wide applications. Computer batteries can be said to belong to this category as well.
Computer batteries are used to power up computers when there is no direct power supply from the connection. But the term can actually be used to denote three different types of batteries - the backup battery or the CMOS battery that would help to hold the settings of the computer like time and date, the bridge battery and the main battery for providing an alternate power supply. The CMOS battery ensures that there would not be a need to reset the date, time and other system settings each time the computer is started. The bridge battery can be spotted only in the portable computers, which would allow the main battery to be replaced if necessary without the need for switching off. The main battery would power the computer when it is not connected to the power supply.
PC batteries can be noticed in the use of laptops. Though many of the models us lithium-ion batteries, thinner models of laptops also use the flatter lithium polymer technology. The nickel metal hydride batteries that existed prior to these models have been replaced. The battery life of the personal computers can vary a lot depending on the workload and the model of the device. While some can be powered only for a few hours, others can last for more than a day. However, it is true that the performance of a battery decreases over time with regular charging and discharging phases. The substantial reduction in capacity would become quite apparent and evident after some years of use. These are, however, highly dependent on the designs and the charging and discharging patterns of the battery.
PC batteries can also be in the form of uninterruptible power supplies that can be found in computers systems to provide power in emergency situations. These devices would offer an auxiliary source of power when the input power source or the main source fails. The supplied energy is stored in batteries, supercapacitors, and flywheels. The runtime of such a source might be short but it would generally be enough to get connected to another power source or to shut down the system properly.
Thus the batteries are mostly used to offer an alternative source of power to the systems while switching or when the direct power source is not available.