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Using a Battery

Dell™ Latitude™ D420 User's Guide

Battery Performance

NOTE: For information about the Dell warranty for your computer, see the Product Information Guide or separate paper warranty document that shipped with your computer.

For optimal computer performance and to help preserve BIOS settings, operate your Dell™ portable computer with the main battery installed at all times. One battery is supplied as standard equipment in the battery bay.

NOTE: Because the battery may not be fully charged, use the AC adapter to connect your new computer to an electrical outlet the first time you use the computer. For best results, operate the computer with the AC adapter until the battery is fully charged. To view battery charge status, access the Control Panel® Power Options, and then click the Power Meter tab.

NOTE: Battery operating time (the time the battery can hold a charge) decreases over time. Depending on how often the battery is used and the conditions under which it is used, you may need to purchase a new battery during the life of your computer.

Battery operating time varies depending on operating conditions.

Operating time is significantly reduced when you perform operations including, but not limited to, the following:

• Using optical drives
  
  
• Using wireless communications devices, PC Cards, ExpressCards, media memory cards, or USB devices
  
  
• Using high-brightness display settings, 3D screen savers, or other power-intensive programs such as 3D games
  
  
• Running the computer in maximum performance mode (see Configuring Power Management Settings)
  
  

NOTE: It is recommended that you connect your computer to an electrical outlet when writing to a CD or DVD.

You can check the battery charge before you insert the battery into the computer (see Checking the Battery Charge). You can also set power management options to alert you when the battery charge is low (see Configuring Power Management Settings).

CAUTION: Using an incompatible battery may increase the risk of fire or explosion. Replace the battery only with a compatible battery purchased from Dell. The lithium ion battery is designed to work with your Dell computer. Do not use a battery from another computer with your computer.

CAUTION: Do not dispose of batteries with household waste. When your battery no longer holds a charge, call your local waste disposal or environmental agency for advice on disposing of a lithium-ion battery. See "Battery Disposal" in the Product Information Guide.

CAUTION: Misuse of the battery may increase the risk of fire or chemical burn. Do not puncture, incinerate, disassemble, or expose the battery to temperatures above 65°C (149°F). Keep the battery away from children. Handle damaged or leaking batteries with extreme care. Damaged batteries may leak and cause personal injury or equipment damage.

Checking the Battery Charge

The Dell QuickSet Battery Meter, the Microsoft Windows Power Meter window and icon, the battery charge gauge and health gauge, and the low-battery warning provide information about the battery charge.

Dell™ QuickSet Battery Meter

If Dell QuickSet is installed, press <Fn><F3> to display the QuickSet Battery Meter. The Battery Meter displays status, battery health, charge level, and charge completion time for the battery in your computer.

For more information about QuickSet, right-click the icon in the taskbar, and click Help.

Microsoft® Windows® Power Meter

The Windows Power Meter indicates the remaining battery charge. To check the Power Meter, double-click the icon on the taskbar.

If the computer is connected to an electrical outlet, a icon appears.

Charge Gauge

By either pressing once or pressing and holding the status button on the charge gauge on the battery, you can check:

• Battery charge (check by pressing and releasing the status button)
  
  
• Battery health (check by pressing and holding the status button)
  
  

The battery operating time is largely determined by the number of times it is charged. After hundreds of charge and discharge cycles, batteries lose some battery health (charge capacity). That is, a battery can show a status of "charged" but maintain a reduced battery health (charge capacity).

Check the Battery Charge

To check the battery charge, press and release the status button on the battery charge gauge to illuminate the charge-level lights. Each light represents approximately 20 percent of the total battery charge. For example, if the battery has 80 percent of its charge remaining, four of the lights are on. If no lights appear, the battery has no charge.

Check the Battery Health

NOTE: You can check battery health in one of two ways: by using the charge gauge on the battery as described below and by using the Battery Meter in Dell QuickSet. For information about QuickSet, right-click the icon in the taskbar, and click Help.

To check the battery health using the charge gauge, press and hold the status button on the battery charge gauge for at least 3 seconds. If no lights appear, the battery is in good condition, and more than 80 percent of its original charge capacity remains. Each light represents incremental degradation. If five lights appear, less than 60 percent of the charge capacity remains, and you should consider replacing the battery. See Specifications for more information about the battery.

Low-Battery Warning

NOTICE: To avoid losing or corrupting data, save your work immediately after a low-battery warning. Then connect the computer to an electrical outlet. If the battery runs completely out of power, hibernate mode begins automatically.

By default, a pop-up window warns you when the battery charge is approximately 90 percent depleted. You can change the settings for the battery alarms in QuickSet or the Power Options Properties window. See Configuring Power Management Settings for information about accessing QuickSet or the Power Options Properties window.

Conserving Battery Power

Perform the following actions to conserve battery power:

• Connect the computer to an electrical outlet when possible because battery life is largely determined by the number of times the battery is used and recharged.
  
  
• Place the computer in standby mode or hibernate mode when you leave the computer unattended for long periods of time (see Power Management Modes).
  
  
• Use the Power Management Wizard to select options to optimize your computer's power usage. These options can also be set to change when you press the power button, close the display, or press <Fn><Esc>.
  
  

NOTE: See Power Management Modes for more information on conserving battery power.

Power Management Modes

Standby Mode

Standby mode conserves power by turning off the display and the hard drive after a predetermined period of inactivity (a time-out). When the computer exits standby mode, it returns to the same operating state it was in before entering standby mode.

NOTICE: If your computer loses AC and battery power while in standby mode, it may lose data.

To enter standby mode:

• Click Start® Shut Down® Stand by.
  
  

or

• Depending on how you set the power management options in the Power Options Properties window or the QuickSet Power Management Wizard, use one of the following methods:
  
  
• Press the power button.
  
  
• Close the display.
  
  
• Press <Fn><Esc>.
  
  

To exit standby mode, press the power button or open the display depending on how you set the power management options. You cannot make the computer exit standby mode by pressing a key or touching the touch pad.

Hibernate Mode

Hibernate mode conserves power by copying system data to a reserved area on the hard drive and then completely turning off the computer. When the computer exits hibernate mode, it returns to the same operating state it was in before entering hibernate mode.

NOTICE: You cannot remove devices or undock your computer while your computer is in hibernate mode.

Your computer enters hibernate mode if the battery charge level becomes critically low.

To manually enter hibernate mode:

• Click Start® Turn off computer, press and hold <Shift>, and then click Hibernate.
  
  

or

• Depending on how you set the power management options in the Power Options Properties window or the QuickSet Power Management Wizard, use one of the following methods to enter hibernate mode:
  
  
• Press the power button.
  
  
• Close the display.
  
  
• Press <Fn><F1>.
  
  

NOTE: Some PC Cards or ExpressCards may not operate correctly after the computer exits hibernate mode. If this occurs, remove and reinsert the card (see Installing a PC Card or 34-mm ExpressCard), or simply restart (reboot) your computer.

To exit hibernate mode, press the power button. The computer may take a short time to exit hibernate mode. You cannot make the computer exit hibernate mode by pressing a key or touching the touch pad. For more information on hibernate mode, see the documentation that came with your operating system.

Configuring Power Management Settings

You can use the QuickSet Power Management Wizard or Windows Power Options Properties to configure the power management settings on your computer.

• To access the QuickSet Power Management Wizard, double-click the icon in the taskbar. For more information about QuickSet, click the Help button in the Power Management Wizard.
  
  
• To access the Power Options Properties window, click Start® Control Panel® Performance and Maintenance® Power Options. For information on any field in the Power Options Properties window, click the question mark icon on the title bar and then click the area where you need information.
  
  

Charging the Battery

NOTE: With Dell™ ExpressCharge™, when the computer is turned off, the AC adapter charges a completely discharged battery to 80 percent in about 1 hour and to 100 percent in approximately 2 hours. Charge time is longer with the computer turned on. You can leave the battery in the computer for as long as you like. The battery's internal circuitry prevents the battery from overcharging.

When you connect the computer to an electrical outlet or install a battery while the computer is connected to an electrical outlet, the computer checks the battery charge and temperature. If necessary, the AC adapter then charges the battery and maintains the battery charge.

If the battery is hot from being used in your computer or being in a hot environment, the battery may not charge when you connect the computer to an electrical outlet.

The battery is too hot to start charging if the light flashes alternately green and orange. Disconnect the computer from the electrical outlet and allow the computer and the battery to cool to room temperature. Then connect the computer to an electrical outlet to continue charging the battery.

For more information about resolving problems with a battery, see Power Problems.

Replacing the Battery

CAUTION: Before performing these procedures, turn off the computer, disconnect the AC adapter from the electrical outlet and the computer, disconnect the modem from the wall connector and computer, and remove any other external cables from the computer.

CAUTION: Using an incompatible battery may increase the risk of fire or explosion. Replace the battery only with a compatible battery purchased from Dell. The battery is designed to work with your Dell™ computer. Do not use a battery from other computers with your computer.

NOTICE: You must remove all external cables from the computer to avoid possible connector damage.

To remove the battery:

1. If the computer is connected to a docking device (docked), undock it. See the documentation that came with your docking device for instructions.
   
   
2. Ensure that the computer is turned off.
   
   
3. Slide the two battery-bay release latches on the bottom of the computer until the latches click.
   
   
4. Slide the battery away from the computer.
   
   

1

battery

2

battery-bay release latches (2)

To replace the battery, place the battery in the bay and press down until the battery-bay latch release clicks.

Storing a Battery

Remove the battery when you store your computer for an extended period of time. A battery discharges during prolonged storage. After a long storage period, recharge the battery fully before you use it (see Charging the Battery).

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