Differences between NiCad , NiMH and Lithium Ion batteries ?

What are the differences between
NiCad , NiMH and Lithium Ion
batteries ?


Batteries in portable consumer
devices such as a laptop , camcorder ,
cellular phone, etc . , are typically made
using either Nickel Cadmium (NiCad ) ,
Nickel Metal Hydride (NiMH ) or
Lithium Ion (Li - Ion ) battery cell
chemistry. Each type of rechargeable
battery chemistry has its own unique
characteristics :


NiCad Batteries
( Nickel Cadmium )

The main difference between the two
is that NiMH battery (the newer
technology of the two ) offers higher
energy density than NiCads . In other
words , the capacity of a NiMH is
approximately twice the capacity of its
NiCad counterpart. What this means
is for you is increased run - time from
the battery with no additional bulk or
weight . NiMH also offers another
major advantage : NiCad batteries tend
to suffer from what is called the
" memory effect "



NiMH Batteries
(Nickel Metal Hydride )

NiMH batteries are less prone to
develop this problem and thus require
less maintenance and conditioning .
NiMH batteries are also
environmentally friendlier than NiCad
batteries since they do not contain
heavy metals (which present serious
landfill problems).

Note :Not all devices can accept both
NiCad or NiMH batteries.




Li - Ion Batteries
(Lithium Ion )

Lithium- Ion (Li - Ion) has become the
new standard for portable power in
consumer devices . Li - Ion batteries
produce the same energy as NiMH
battery but weights approximately
20 % - 35 % less .

This is can make a
noticeable difference in devices such
as cellular phones , camcorders or
notebook computers where the
battery makes up a significant portion
of the total weight . Another reason Li -
Ion batteries have become so popular
is that they do not suffer from the
" memory effect " at all . They are also
environmentally friendly because they
don' t contain toxic materials such as
Cadmium or Mercury .



The Do' s and Don ' ts of Battery Use
Battery

Do' s :

Fully charge/ discharge battery up to 4
cycles before achieving full capacity of
a new battery.
Fully discharge and then fully charge
the battery every two to three weeks
for battery conditions .

Run the device under the battery ' s
power until it shuts down or until you
get a low battery warning. Then
recharge the battery as instructed in
the user ' s manual.

Remove from the device and stored in
a cool , dry , clean place if the battery
will not be in use for a month or
longer .

Recharge the battery after a storage
period .

Ensure maximum performance of the
battery by optimizing the device ' s
power management features . Refer to
the manual for further instructions.



Battery Don ' ts:

Do not short - circuit. A short - circuit
may cause severe damage to the
battery.

Do not drop , hit or otherwise abuse
the battery as this may result in the
exposure of the cell contents , which
are corrosive .

Do not expose the battery to moisture
or rain .

Keep battery away from fire or other
sources of extreme heat . Do not
incinerate . Exposure of battery to
extreme heat may result in an
explosion.