The main
laptop
battery (also called the power battery) is the battery pack which
allows a laptop or notebook to operate independently of an
AC power
source. These rechargeable batteries are designed to operate the
computer for a certain amount of time (generally 1 to 4 hours).
What are CMOS or Clock
Batteries?
CMOS & Clock Backup batteries
perform the same function in desktop and
laptop
computers: when the computer is turned off, the battery maintains
the time and date, thus insuring their accuracy when the system is once
again restarted. More importantly, the battery saves the computers BIOS
setup configuration, which allows the system to efficiently reboot once
it is restarted. The computer knows what type of hard drive it is
dealing with, etc. Not surprisingly, these batteries are known
alternatively as CMOS batteries, Real Time Clock (RTC) batteries, or
simply internal batteries.
The most common CMOS battery chemistries are Lithium, Nickel Cadmium
(NiCad) and alkaline. They are usually somewhere in the 3 to 7.2 volt
range and either solder onto the motherboard or plug in via a snap-in
connector (depending upon the computer manufacturers design).
In most cases, replacement of the CMOS
battery is an easy task. It is simply a matter of locating the battery
on the computer's motherboard, removing it and plugging in a new one. As
a rule, internal batteries should be replaced by the same type of
battery which was originally used in the machine or according to the
manufacturers specifications. The major exception to this rule are older
PCs which were manufactured with a NiCad battery soldered onto the
motherboard. These computers usually have a three or four pin male plug,
with two of the pins connected via a jumper (this is generally found in
the same area of the motherboard as the original battery). This plug
gives you the option of leaving the soldered battery in place and
replacing it with a plug-in lithium or alkaline battery. Removing the
jumper tells the computer to ignore the soldered battery and to look to
the pins for its power source. If the motherboard has this provision,
you can install a standard PC plug-in battery instead of removing the
soldered battery and re-soldering a new one (the standard PC plug-in
battery is Battery-Biz part number B-220 (lithium) or B-116 (alkaline).
These batteries are interchangeable). A word of warning: some computers
have 4 pins on the motherboard, whereas today's plug-in batteries come
with a 3 pin connector (one of the pinholes is closed in order to
prevent the user from inadvertently plugging the battery in with
reversed polarity). If this is the case, you should clip the pin from
the motherboard that corresponds to the sealed pinhole on the battery
plug. That pin is nonfunctional and by clipping it you ensure that
future batteries will not be installed on the motherboard with reversed
polarity.IMPORTANT NOTES:
NiCad batteries are rechargeable,
whereas Lithium and alkaline batteries are NOT. Therefore, Lithium and
alkaline batteries must be replaced by equivalent batteries of the same
type. Attempting to replace these non-rechargeable batteries with a
NiCad will result in a nonfunctional battery because the computer lacks
the proper charging circuitry to charge the NiCad battery.
If a motherboard lacks the above-discussed
male pins for an external battery, the NiCad battery MUST be unsoldered
and replaced by a NiCad battery ONLY. Attempting to use an alkaline or
lithium battery in place of NiCad on such a board could be hazardous.
These batteries are not designed to be recharged, and an attempt to do
so may cause the battery to "burst", or explode.
CMOS batteries generally last for two to
three years, although some (especially the lithium type) have been known
to last much longer. Ironically, the less the computer is used the
faster the CMOS battery will run out. This is because when the computer
is turned off the battery begins to function. It is recommended to
replace the CMOS battery approximately once every two years or when
servicing the computer. If the computer has been idle for an extended
length of time it is a good idea to change the battery. Changing the
battery is a relatively easy and inexpensive task, especially (as were
sure many of you out there know) when compared to trying to reboot and
configure a computer which has lost its BIOS settings.
What are RAM or Resume batteries?
Some notebook computers are
designed with a dedicated battery for backing up RAM (random access
memory) functions when the machine temporarily loses power from the main
battery. This feature allows users to change the main battery pack
without losing the current applications and settings residing in memory.
This is called a "battery hot swap" - switching the main battery pack
without having to turn off the computer.
These type of batteries are alternately
known as bridge batteries, RAM batteries, auxiliary batteries or resume
batteries.
Most RAM batteries are rechargeable NiCad or
NiMH and will last around 2-3 years. It is recommended that you replace
your notebook's RAM battery when replacing the CMOS battery.
Most RAM batteries are rechargeable NiCad
or NiMH and will last around 2-3 years. It is recommended that you
replace your notebook's RAM battery when replacing the CMOS battery.
Battery run-time on a laptop is
difficult to determine. Actual battery running time depends upon the
power demands made by the equipment. The use of the screen, the hard
drive and other accessories results in an additional drain upon the
battery, effectively reducing its running time. The total run-time of
the battery is also dependent upon the design of the equipment.
Generally, a new Dekcell battery will run 30% to 50% longer than the old
battery did when it was new.
Is it Possible to Upgrade the Device's
Battery to a Newer Chemistry?
NiCad, NiMH and Li-Ion are all fundamentally different technologies and
cannot be substituted for one another unless the device has been
pre-configured from the factory to accept more than one type of
rechargeable battery. The difference between them stems from the fact
that each technology requires a different charging pattern to be
properly recharged. Therefore, the portable device's charger must be
properly configured to handle a given type of rechargeable battery.
Refer to the owners manual to find out which
rechargeable battery types the particular device supports or use our
QuickFind search engine to find the device in our database. The database
will automatically list all of the battery types supported by the
machine.What is a "smart"
Battery?
Smart batteries have internal
circuit boards with smart chips which allow them to communicate with the
notebook and monitor battery performance, output voltage and
temperature. Smart batteries will generally run 15% longer due to their
increased efficiency and also give the computer much more accurate "fuel
gauge" capabilities to determine how much battery running time is left
before the next recharge is required.
How Can I Maximize Battery Performance?
There are several steps you can
take to insure that you get maximum performance from the battery:
Break In New Batteries
New batteries come in a
discharged condition and must be fully charged before use. It is
recommended that you fully charge and discharge the new battery two to
four times to allow it to reach its maximum rated capacity.
Prevent the Memory Effect
Keep the
laptop
battery healthy by fully charging and then fully discharging it at
least once every two to three weeks. Exceptions to the rule are Li-Ion
batteries which do not suffer from the memory effect.
Keep the
Laptop
Batteries Clean
It's a good idea to clean dirty
battery contacts with a cotton swab and alcohol. This helps maintain a
good connection between the battery and the portable device.
Exercise the Battery
Do not leave the battery dormant
for long periods of time. We recommend using the battery at least once
every two to three weeks. If a battery has not been used for a long
period of time, perform the new battery break in procedure described
above.Battery Storage
If you don't plan on using the
battery for a month or more, we recommend storing it in a clean, dry,
cool place away from heat and metal objects. NiCad, NiMH and Li-Ion
batteries will self-discharge during storage; remember to break them in
before use. Sealed Lead Acid (SLA) batteries must be kept at full charge
during storage. This is usually achieved by using special trickle
chargers. If you do not have a trickle charger, do not attempt to store
SLA batteries for more than three months.
For Notebook Users
To get maximum performance from
the battery, fully optimize the notebooks power management features
prior to use. Power management is a trade off: better power conservation
in exchange for lesser computer performance. The power management system
conserves battery power by setting the processor to run at a slower
speed, dimming the screen, spinning down the hard drive when it's not in
use and causing the machine to go into sleep mode when inactive. The
notebook users guide will provide information relating to specific power
management features.How Long Do
Batteries Last (What is the Life Span of the New Battery)?
The life span of a rechargeable
battery operating under normal conditions is generally between 500 to
800 charge-discharge cycles. This translates into one and a half to
three years of battery life for the average user. As the rechargeable
battery begins to die you will notice a decline in the running time of
the battery. When a new battery that originally powered the notebook for
two hours is only giving an hour's worth of use it's time for a new one.
The New Battery Isn't Charging. What's
the Deal?
New
laptop
batteries are shipped in a discharged condition and must charged
before use. We generally recommend an overnight charge (approximately
twelve hours). Refer to the user's manual for charging instructions.
Rechargeable batteries should be cycled (fully charged and then fully
discharged) two to four times initially to allow them to reach their
full capacity. (Note: it is normal for a battery to become warm to the
touch during charging and discharging).
New batteries are hard for the device to
charge; they have never been fully charged and are therefore "unformed".
Sometimes the device's charger will stop charging a new battery before
it is fully charged. If this happens, remove the battery from the device
and then reinsert it. The charge cycle should begin again. This may
happen several times during the first battery charge. Don't worry; it's
perfectly normal.
And now the disclaimer: Any statements and
data in this file are for general information purposes. They represent
the latest technical status at the time of publishing. Battery-Biz
reserves the right to change the data in this file without prior notice.
The technical information is given in a descriptive way and does not
guarantee any properties or enlarge any warranties given.
