The App Magic Battery shows the battery level of supported input devices and headphones that are connected via Bluetooth in the menu bar. Internal batteries are also supported.
 

Magic Battery supports all Apple input and audio devices. Battery information will be shown in the menu bar and the main window.

The following devices are supported:

Input devices:
• Apple Magic Mouse
• Apple Magic Mouse 2
• Apple Magic Trackpad 2
• Apple Wireless Keyboard
• Apple Wireless Trackpad
• Logitech MX Anywhere 3

Headphones:
• AirPods
• AirPods Pro
• AirPods Max
• Beats Solo 3
• Beats X
• Beats Studio 3 Wireless

Other devices:
• Apple iPad (all models)
• Apple iPhone (all models)

The app features:
• Modern GUI for displaying connected devices and their battery levels.
• Shows the percentage of the internal battery including how long the battery will last.
• You can choose between a detailed, a compact or an icon-only view. In the detailed view, the battery level is shown next to the device icon. In the icon-only view, the battery levels are shown once the menu of the app is opened. The compact view shows all the information in a way that very little space is used.
• Apple Silicon support.
• Connected or disconnected devices are detected automatically. The view is then adjusted accordingly.
• Receive notifications when the battery level of a device is reaches 20%.
• Support for auto-start: The app is started as soon as the user is logged in (optional).

 

Supported Operation System:
• 64-bit processor
• macOS 11.0 or later

 

Mac App Store : https://apps.apple.com/app/magic-battery/id1240063289