Laptop batteries have evolved to meet up with the power demand and size requirements of mobile computing. There is a trend towards packing more energy-efficient cells into smaller packages while keeping down the total weight.

1. [Short Guide on Laptop Batteries]
Laptop batteries have evolved to meet up with the power demand and size requirements of mobile
computing. There is a trend towards packing more energy-efficient cells into smaller packages while
keeping down the total weight.
The first laptop batteries are the Rechargeable Nickel Cadmium batteries. While batteries are no longer
used, they once were the only kinds available. The disadvantages of Nickel Cadmium batteries include
their weights, lower efficiencies and the “memory effect”. The memory effect is a common fault of
Nickel-based batteries. Even with Nickel Metal Hydride batteries that replaced Nickel Cadmium ones in
laptops, the memory effect can be noticed, even though it is less.
The memory effect affects the efficiency of Nickel-based laptop batteries by keeping the characteristics
of the last charging cycle. This means that if in the previous cycle the laptop battery is not fully charged,
the battery will remember this and cut down on the energy output of the next cycle.
However, for all the demerits of Nickel-based laptop batteries, they are cheap to produce and safe to
make. Nickel Metal Hydride batteries are more reliable and provide better output than Nickel Cadmium
ones.
Lithium Ion cells are today’s laptop battery leader. While there are different types of this kind, they are
all noted for their energy efficiencies, reduced weight, better output and ease of manufacturing
different sizes and shapes of them.
So what makes Lithium better for laptop batteries?
First the basic chemistry: Lithium is the lightest metal, it has the largest electrochemical potential and it
packs the biggest energy density for its weight. However, it is rather unstable as a metal especially
during charging. The workaround is to use non-metallic Lithium sources which are much safer while
sacrificing only a slight energy density.
Therefore, today’s Lithium Ion laptop batteries use intercalated Lithium compounds for electrodes
rather than Lithium metal. During discharge, Lithium ions carry current from the negative electrode to
the positive one. The reverse occurs while charging the battery.
Clear advantages of Lithium Ion batteries include:
• higher energy densities (at least twice that of Nickel Cadmium), low self-discharge (half of the
rate for Nickel-based batteries),
• low maintenance and no memory effects.

2. • They are also much lighter and can be made for specialty equipment with special power
requirements.
All of these make Lithium Ion cells ideal as laptop batteries.
However, Lithium Ion batteries are not without their demerits. They are more susceptible to aging, more
sensitive to high temperatures and are more expensive. To even make them more costly, these batteries
require special circuits to protect them from overheating and maintain output within safe limits. As
laptop batteries, they also require onboard computers to manage them. Furthermore, since
manufacturers are constantly developing better, slimmer and specialty Lithium Ion batteries, the metals
and chemicals in these cells are always changing, making it difficult for economy of scale of materials
and processes to reduce costs after a while.
In spite of the high cost and few limitations, Lithium Ion batteries still represent the biggest proportion
of laptop batteries. In fact, the most economical Lithium Ion battery is the kind produced for mobile
computing needs especially for laptops. This type of Lithium Ion batteries is cylindrical with a dimension
of 18 mm x 650 mm.
In all, scalability and better efficiency are the main reasons why Lithium Ion batteries are the
commonest and the most promising laptop batteries. These are the reasons why we use them too. They
are light, energy-efficient, durable, simple and require low maintenance. When you weigh all the factors
involved, you will see that Lithium Ion batteries represent the best choice both for users and
manufacturers, if you need true mobility and reliable power.
Source: Needbattery.com/laptop