InfoIf you have MacBook or MacBook Pro, MacBook Air, you can enable displaying of battery status in Guest operating system.
"Enable battery in virtual machine" - If you enable this option, the battery status will be displayed in your virtual machine each time your Mac laptop computer runs on batteries.
You can change settings for "Enable battery in virtual machine" as described bellow:
1. Start Parallels Desktop
2. Start required Virtual Machine
3. Click Configure button in the Toolbar
4. Select Optimization option in the left pane
5. In the Optimize power consumption for section, select the Enable battery in virtual machine checkbox
6. Click OK
Now you can check the battery status in the Virtual Machine tray, when the power cable is unplugged from Mac.
NOTE: It is possible only if battery status dislplaying is supported by your Guest OS, for example in Linux OSes like OpenSuse 10.x ,11, Ubuntu 8.x, Windows XP, Windows Vista.
You can enable battery, if you are programming application related on ACPI, or calling ACPI API functions.