The battery icon changes appearance to display the current state of your battery, so that you can view how much charge remains on your battery at a glance.
When the battery charge is above 25 percent, the battery icon is green.
When the battery charge reaches 25 percent, a yellow triangle with an exclamation point (!) appears above the green battery icon.
When the charge reaches the low-battery level, an "X" appears above the green battery icon.
If you hover over the battery icon, you can see the percentage of remaining battery charge, the amount of time remaining before the battery dies, and the power plan that you're using.
If your battery charge is low, and you have customized your power plan settings to notify you when the charge reaches the low-battery level, that notification appears above the battery icon.
When you right-click the battery icon, a menu appears with the following options:
Power Options. Opens the Select a power plan page, where you can change power settings or select a power plan.
Windows Mobility Center. Opens Windows Mobility Center, where you can adjust several of the most commonly used mobile PC settings from a single location. For example, you can change your display brightness, adjust speaker volume, check the status of your battery, and more.
Show System Icons. Opens the Taskbar and Start Menu Properties dialog box, where you can hide the battery icon by clearing the Power check box.
When you click the battery icon, the battery meter appears. It lists all available batteries and their remaining charge.
You can also select any of the default power plans from the battery meter. To change a power plan's settings or to select a power plan that isn't shown on the battery meter, click More power options.