Dell LATITUDE D400 - Manual (Page 66)

Health Gauge
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 charge capacity, or battery health. To check the battery health, 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 operating time.
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, or install a second battery in the module bay. If the battery runs completely out of
power, standby mode begins automatically.
A pop-up window warns you when the battery charge is approximately 90 percent depleted. For more information on low-
battery alarms, see " Power Management ."
Charging the Battery
NOTE: Charge time is longer with the computer turned on. You can leave the battery in the computer as long as you
like. The battery 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 warm from being used in your computer or being in a warm environment, the battery may not charge when
you connect the computer to an electrical outlet.
The battery is too warm 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 on resolving problems with a battery, see " Power Problems ."