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.
1Ensure that the computer is turned off, suspended in a power management mode, or connected to an electrical outlet.
2If the computer is connected to a docking device (docked), undock it. See the documentation that came with your docking device for instructions.
3Slide and hold the
Dell Precision Mobile Workstation M20 Quick Reference Guide
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