A Python CLI for Windows to notify when battery is below certain set percentage

Windows Management Instrumentation module(WMI)

You can install it using pip. Use command pip install battery_status in terminal. Alternatively you can use easy_install battery_status to install it.

Since this is a background application, you can run it in Bash using commands check_battery_status for checking battery percentage and start_battery_notifier for getting notification on 20 percentage or less. You will hear sound as notification.