To do so, simply move the mouse around and look for a response from the cursor on your Mac's screen.

If your mouse isn't connected, it may not be on. You can turn on your mouse by flipping it over and sliding the switch near the front of the mouse up so that it displays green.
 It's in the top-left corner of your Mac's screen. Doing so will prompt a drop-down menu., This option is near the top of the drop-down menu., You'll see this option in the second row of options in the System Preferences window., It's in the bottom-left corner of this window; you should see a battery icon here, with the percentage of your mouse's remaining battery life listed to the right of the battery icon.
Make sure your mouse is connected to your Mac.
Click the Apple Menu icon.
Click System Preferences.
Click Mouse.
Look for the "Mouse battery level" value.
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