Dell Latitude D820: Low-Battery Warning Charging the Battery Replacing the Battery

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Quick Reference Guide

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 the specifications in your 

User’s Guide

. 

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. 

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.

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.

NOTICE: 

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

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. 

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.