Dell Precision Mobile Workstation M20 Quick Reference Guide 13
Charging the Battery
NOTE: The AC adapter charges a completely discharged battery in approximately 1 hour with the
computer turned off. Charge time is longer with the computer turned on. You can leave the battery in the
computer 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 your
User’s Guide
.
Removing a Battery
CAUTION: Before performing these procedures, disconnect the modem from the telephone wall jack.
For information about removing the second battery, see your
User’s Guide
.
NOTICE: If you choose to replace the battery with the computer in standby mode, you have up to 1
minute to complete the battery replacement before the computer shuts down and loses any unsaved
data.
1
Ensure that the computer is turned off, suspended in a power management mode, or
connected to an electrical outlet.
2
If the computer is connected to a docking device (docked), undock it. See the documentation
that came with your docking device for instructions.
3
Slide and hold the battery-bay (or module-bay) latch release on the bottom of the computer,
and then remove the battery from the bay.