Section 2: Laptops and Portable Devices

Understanding and working with portable computing devices is becoming increasingly important in the current IT environment. With notebook computers accounting for over half of the new computers being purchased today, CompTIA’s acknowledgement that laptops and portable devices are important is shown with a whole section focused on mobile devices.

In this section, you will learn about mobile technologies, how they make laptop computers function, primary differences between desktop computers and laptops, upgrading laptop computers, diagnosing problems on laptop computers, and preventative maintenance techniques with laptops.

Fundamentals of Laptops

Laptop Technologies

Battery

One of the most obvious differences between a laptop and a desktop computer is the ability to use a laptop where you do not have an AC outlet. Battery technology has evolved over the past decade from manufacturers primarily using NiCad batteries to new Lithium Ion and NiMH batteries. Newer batteries (such as the ones in Apple’s portable computers) can get five or more hours of use – versus older NiCad batteries where you were lucky to get two hours!

Alkaline

You know alkaline batteries by the common ones you use everyday – AA, AAA, C, D are all Alkaline batteries. Alkaline batteries are frequently used in PDAs, but not used in laptops or notebooks.

NiCad (Nickel Cadium)

NiCad was one of the first rechargeable battery technologies used in laptop computers. It is heavier than competing battery technology and suffers from “memory effect.” Over time, these batteries lose the ability to fully recharge. Most NiCad batteries last for 3-4 hours, but over time, they can degrade to 2 hours, or even less than 1 hour of charge. NiCad are also the cheapest batteries to manufacture.

NiMH (Nickel Metal Hydride)

NiMH batteries weigh the same as NiCad batteries but do not last as long as Li-Ion batteries do. They are the most environmentally friendly of these batteries as they do not contain toxic chemicals. They are the most expensive of these battery types.

Li-Ion (Lithium Ion)

A Li-Ion battery is lightweight and holds a longer charge than NiMH or NiCad. Additionally, Li-Ion doesn’t have the “memory effect” – so it can be charged no matter how full it already is. A Lithium Ion battery is considered to be the best battery – it is the most expensive, but the combination of light weight and longer operation times means it is much more effective for portable computing than the competing technologies.

Memory Effect

You’ve probably heard the term “memory effect” before. Memory effect describes batteries which lose some of their ability to charge over time. Some batteries, such as NiCad batteries, require an occasional drain to 0% or 1% to be able to be fully recharged. If, over the life of using your battery, you consistently let the battery get down to about 50% charge, then recharge it, over time the battery has “memory effect” and is not able to be fully charged. Users with laptops with NiCad batteries should be informed that they need to frequently let the battery run down to 0% charge before recharging.

Exam Moment

Which of the three primary laptop battery types – NiCad, NiMH, and Li-Ion – is considered the best?

Answer: Li-Ion. Its combination of light weight and good performance outweighs the other two. It is the most expensive of the three, but by far, the best option.

AC Adapter

Notebook computers use an AC Adapter to charge the battery and run the computer while the battery is being charged. There are two primary type of AC Adapters: built-in and brick-style. A built-in AC adapter is integrated into the laptop itself and only requires a cable to the AC outlet. A brick style AC adapter is an external “brick-shaped” adapter which must be used to power the laptop.

IBM Brick Style AC Adapter

The AC Adapter’s primary purpose is to convert the AC power from the wall outlet into DC power which the computer uses.