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Batteries: Dell Latitude L400 User's Guide
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Batteries: Dell™ Latitude™ L400 User's
Guide
About the Batteries
Your computer includes a 4-cell or 6-cell lithium ion battery that provides power when
an electrical outlet is not available. The battery is installed on the underside of the
computer and forms part of the bottom of the computer. Lithium ion batteries are longer
lived than conventional batteries and do not require replacement as often. You do not need
to drain a lithium ion battery completely before recharging it.
Do not place spent batteries with common household waste products.
See Battery Disposal for more information.
Keep the following information in mind when you are running your
computer from the battery:
- Battery performance (life between charges) varies, depending on which power management
features are enabled and which application programs you are using.
- The integrated battery
charge gauge lets you check the charge status of an
installed or uninstalled battery at any time.
- The battery’s self-test capability alerts you to battery
conditions such as low charge.
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NOTE: If the battery is totally drained the alert
functions will not operate. |
- The Battery Auto-Learning utility helps maintain battery gauge
accuracy.
- A battery has a life span of up to 300 full
charges, provided it is charged at normal room temperature. The battery degrades with time
and at that point should be operating at approximately 80 percent of its original
capacity.
NOTICE: The batteries are designed to work only with Dell
Latitude L400 computers. Do not use Latitude L400 batteries with other computers, and do not use batteries from
other computers with Dell Latitude L400 computers.
The battery is partially charged when you receive it. Dell recommends that you charge
your battery to full capacity before using it to power the computer.
If you are powering the computer from a battery, try to conserve
battery power. A number of factors affect battery operating time:
- Power conservation features that you use
- Type of display and microprocessor installed
- Brightness setting of the display
- Use of storage media
- Number and type of external devices and type of PC Cards that you use
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NOTE: You can extend battery life by removing PC
Cards when they are not being used. |
- Kinds of application programs that you run
- Capacity of the memory module installed (the higher the capacity, the
more power used)
When you activate standby mode (known as suspend
in Microsoft® Windows NT®), the computer can
remain in standby mode on battery power for approximately one week (if the battery was
fully charged before activating suspend or standby mode).
If you are going to store the computer, disconnect all devices and
turn off the computer. Remove the battery when you store your computer for an extended
period of time. A battery will drain when not in use during prolonged storage. After a
long storage period, recharge the battery fully before you attempt to run your computer
from battery power.
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NOTE: To extend battery life, store batteries at
room temperature. |
Each time you connect the computer to an electrical outlet or install a battery in a
computer that is connected to an electrical outlet, the computer checks the battery's
charge. The AC adapter charges the battery (if needed) and then maintains the battery's
charge.
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NOTE: For maximum battery performance, charge the
battery only at room temperature. |
The battery status indicator (see Figure 1)
normally turns green while the battery
is charging and then flashes green when the charge cycle is
complete. It takes about 1.5 hours to completely charge the battery, whether the computer
is turned on or off.
Figure 1. Battery Status Indicator
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| 1 |
Battery status indicator |
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NOTE: You can leave the battery in the computer as
long as you like. The battery's integrated circuitry prevents the battery from
overcharging. |
If your battery is hot from being used in your computer or being in
a hot environment, take note of the following precautions:
- A hot battery will not charge when you connect the AC adapter to the
computer. This safety feature is important because charging a hot battery shortens the
battery’s life span and may damage the battery and the computer.
- If the computer is not allowed to return to room temperature, the
battery stops charging before it reaches its full capacity.
To replace a battery in the battery bay (see Figure
2), perform the following steps .
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NOTES: If necessary, print these instructions for
reference before proceeding. Dell recommends that you
turn the computer off before replacing the battery.
If you want to replace the battery while the computer is running,
you must first connect the computer to an electrical outlet or enter standby
(or suspend) mode or
hibernate
(S2D) (or suspend-to-disk [S2D])
mode. You cannot replace the battery while the computer is running on battery power. |
- If the computer is docked, undock it. (See the documentation that
came with your docking device.)
NOTICE: If you choose to replace the battery with the
computer in suspend (or standby) mode, you have up to 2 minutes to complete the battery
replacement.
- Connect the computer to an electrical outlet and then preserve your
data by placing the computer in standby (or suspend) mode.
Press <Fn><Esc> (or <Scroll Lock><Esc> on an external
keyboard if the External Hot Key option
is enabled in the system setup program).
- Remove the battery from the battery
bay.
Close the computer display and turn the computer over. Slide the battery bay latch to the
unlock position (see Figure 2), causing the battery to pop up
slightly on one side. While keeping the latch in the unlock position, pivot the battery up
and out of the bay. Release the latch.
Figure 2. Removing a Battery
- Position the new battery as shown in Figure 2, and lower the outside
edge of the battery into the battery compartment.
Four small tabs on the battery fit into four slots in the side wall of the computer.
- Press the battery firmly into place, flush with the surrounding
surface.
Make sure that the battery latch is completely closed before turning the computer
right-side up.
- If you put the computer into standby (or suspend) mode in step 2,
press the power button to resume normal operation.
Battery Charge Gauge
The battery charge gauge, located on the battery and accessible on the underside of the
computer, consists of four indicators and a test button. Each indicator represents 25
percent of full charge. If only one indicator lights
up, recharge the battery before using it.
To check the charge level, press the battery test button (see Figure 3). The appropriate number of indicators lights up for a few
seconds to indicate the amount of charge remaining in the battery.
Figure 3.
Battery Charge Gauge
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| 1 |
Battery charge indicators (4) |
| 2 |
Battery test button |
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NOTES: A charge indicator that blinks rapidly
indicates a temporary failure or a potentially recoverable failure such as overheating.
Allow the battery to cool for several minutes before checking the charge level
again. If the battery has permanently failed or
completely discharged, no charge indicators will light when you press the battery test
button. If you install a failed or completely discharged battery in the computer and the battery status indicator
turns red, the battery has failed. If the battery status indicator turns red, allow the
battery to charge overnight and check it the next day. If the battery is fully discharged,
it takes a much longer time than usual to recharge it.
To purchase a new battery, call Dell or
access the Dell World Wide Web site at http://www.dell.com. Dispose of the old battery properly. |
The battery charge
gauge uses its four indicator lights to show the percent of
charge remaining in the battery:
- If one indicator lights up, the battery has 1 to 25 percent of its
charge remaining.
- If two indicators light up, the battery has 26 to 50 percent of its
charge remaining.
- If three indicators light up, the battery has 51 to 75 percent of its
charge remaining.
- If four indicators light up, the battery has 76 to 100 percent of its
charge remaining.
First Low-Battery Warning
Low-battery operation differs depending on your operating
system:
- For Advanced Configuration and Power Interface
(ACPI) compliant systems such as Windows® 98, Windows 2000, and Windows Me, you can
configure low-battery notifications and actions through the Power Management
Properties window (Windows 98) or the Power Options Properties
window (Windows 2000 or Windows Me).
- For Advanced Power Management (APM) compliant
systems such as Windows NT, the first low-battery warning occurs when the battery has
about 20 minutes of life remaining under current conditions and the computer is not
connected to an electrical outlet. The first low-battery warning is indicated in three
ways: a battery warning icon appears on the screen, a triple beep sounds from the speaker,
and the battery status indicator (see Figure 1) flashes amber.
NOTICE: When you receive a
low-battery warning, save your work immediately. Then replace
the battery or connect your computer to an electrical outlet.
Second Low-Battery Warning
Low-battery operation differs depending on your operating
system:
- For ACPI compliant systems such as Windows 98, Windows 2000, and Windows Me, you can
configure low-battery notifications and actions through the Power Management
Properties window (Windows 98) or the Power Options Properties
window (Windows 2000 and Windows Me).
- For APM compliant
systems such as Windows NT, the second low-battery warning occurs when the battery has
about 15 minutes of life remaining under current conditions and the computer is not
connected to an electrical outlet. The second low-battery warning is indicated in three
ways: the battery status indicator (see Figure 1) turns solid amber, a triple beep sounds from the speaker,
and the computer enters suspend mode immediately after the beep.
If no further input/output
(I/O) activity occurs within a few seconds, the computer enters S2D mode. If the
computer has no S2D file, it stays in suspend mode, in which it can preserve
data for several hours.
If the computer is already in suspend
mode when the second low-battery warning occurs, the computer enters S2D mode immediately. If S2D mode has been
disabled, the computer reenters suspend mode.
NOTICE: To avoid losing data and possibly corrupting data areas
on your hard-disk drive, save your work immediately after a second low-battery warning.
Then connect your computer to an electrical outlet, or place the computer in suspend (or
standby) mode. If the battery runs completely out of power, the computer turns off without
properly closing any open files.
Detecting Battery Problems
A battery problem may prevent the battery from being charged to its full potential and
can lead to unpredictable operation. To obtain a new battery, call
Dell or access the Dell World Wide Web site at http://www.dell.com.
To avoid installing a defective battery in your computer, first
check the battery's charge, indicated by the battery charge indicators on the battery
itself, by pressing the battery test button (see Figure 3).
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NOTE: If the battery has 0 (zero) percent charge,
you cannot use the battery test button to check the battery's capacity. The battery charge
indicators will not light if the battery is completely drained. |
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CAUTION: Do not puncture or incinerate
the battery. |
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NOTE: To purchase
a new battery, call Dell or access the Dell World Wide Web site
at http://www.dell.com. |
Your computer system uses both a lithium-ion battery pack and a
nickel-metal hydride (NiMH) coin cell battery. For instructions about replacing the
lithium-ion battery pack in your computer, see "Replacing
the Battery." The NiMH battery is a long-life battery, and it is very possible
that you will never need to replace it. However, if this battery ever needs to be
replaced, the procedure must be performed by an authorized service technician.
Do not dispose of these batteries along with household waste.
Contact your local waste disposal agency for the address of the nearest battery deposit
site.
About Battery Power
You automatically conserve battery power each time you connect the computer to an
electrical outlet. The battery is even being recharged when you use AC power. The
battery's life expectancy is largely determined by the number of charges it receives, so
use an electrical outlet to run the computer whenever possible.
You can customize power management by individually controlling the
computer's power conservation features. These features reduce
power consumption by monitoring application programs and computer devices for inactivity
and slowing down or stopping some of the computer’s internal devices.
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NOTES: When you use power conservation features,
you often trade some of the performance of the computer for increased battery operating
time. For example, if you turn off the hard-disk drive, you may experience a delay the
next time the computer tries to access the hard-disk drive. Other power conservation features, such as suspend (or standby)
mode, stop almost all system activity. They allow you to maximize power conservation when
your work is interrupted. |
Experiment with power conservation features to achieve the optimum
power conservation for your work environment.
The Battery Auto-Learning utility, available through
the system setup program, helps maintain battery gauge accuracy on your Latitude L400
computer.
The utility allows the battery to learn its full
charge capacity. The computer uses the full charge capacity value to determine the length
of time that the battery can operate on a single charge. An incorrect full charge capacity
value causes the computer to report the remaining battery life incorrectly to the
operating system, which may result in shorter than expected battery life.
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NOTE: The full charge capacity may
vary among batteries and may decrease as the battery goes through multiple charge and
discharge cycles. |
To run the utility, use the Run Battery
Learning option on the Power screen of the system
setup program.
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NOTES: The learning process may take
up to six hours to complete. You can stop the process at any time by pressing <Esc>.
Use the utility if you suspect that the accuracy of
the gauge is incorrect. However, do not run the utility more than once every two
monthsrunning the utility more often reduces the service life of the battery.
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Turning On the Computer
To turn on the computer, press the power button.
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NOTES: If your computer's operating system is
"locked up"—that is, it does not respond to commands—press and hold
down the power button for at least five seconds to turn off the computer. If the operating system locks up and does not respond to the power
button, you can restart the computer using the reset switch on the bottom of the
computer. To do so, straighten a paper clip and press it into the reset switch access hole for about one second. |
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