The most recent iteration of the Magic Mouse has its Lightning charging port on the bottom, unlike the Magic Keyboard and Magic Trackpad, which work when plugged in. To check if your Magic Mouse, TrackPad or Magic Keyboard needs charging before it alerts you, look in one of these spots. If your menu bar is displaying the Bluetooth icon, click it, and the charge level should show up. Or click the Control Center icon on the menu bar and click Bluetooth. You can also look in System Preferences, in either the Bluetooth preference pane, Trackpad preference pane or the Mouse preference pane. In our experience, the Bluetooth menu is the easiest, but Control Center and the Preference panes are the most reliable—sometimes the charge level doesn’t appear in the menu.